WO2012177072A2

WO2012177072A2 - Dehumidification-type air cleaner and control method thereof

Info

Publication number: WO2012177072A2
Application number: PCT/KR2012/004937
Authority: WO
Inventors: Hyun-Jin Hong; Chan-Jung Park; Hyung-Tae Kim; Sang-Woo Kang; Dong-Min Oh; Myung-Jin Park; Chan-Yong Lee; Sang-Gu SIM; Sung-Jin Kim
Original assignee: Woongjin Coway Co., Ltd
Priority date: 2011-06-24
Filing date: 2012-06-22
Publication date: 2012-12-27
Also published as: WO2012177072A3; CN103620313B; JP2014517251A; CN103620313A

Abstract

There are provided a dehumidification-type air cleaner and a control method thereof. A dehumidification-type air cleaner includes, an air purification operation of setting a rotational speed of a intake fan according to a pre-set purification mode and filtering out contaminants from external air introduced according to a rotation of the intake fan, a dehumidification operation signal input operation of receiving a dehumidification operation signal for operating a dehumidifying unit to remove vapor included in the external air, a dehumidifying operation of resetting the rotational speed of the intake fan according to the dehumidification operation signal when the purification mode is a general purification mode, and operating the dehumidifying unit to perform a dehumidification operation and a function purification operation of maintaining the rotational speed of the intake fan when the purification mode is a function purification mode and not performing the dehumidifying operation.

Description

DEHUMIDIFICATION-TYPE AIR CLEANER AND CONTROL METHOD THEREOF

The present invention relates to a dehumidification-type air cleaner and a control method thereof, and more particularly, to an air current force (or air volume) control method for controlling an air current force of a dehumidification-type air cleaner to effectively provide an air cleaning function and a dehumidification function with the dehumidification-type air cleaner, and a dehumidification-type air cleaner using the same.

In general, an air cleaner intakes contaminated indoor air to filter out contaminants such as dust, odor particles, or the like, contained therein, to thus produce purified air. The purified air is expelled to the outside of the air cleaner, namely, to an indoor area to purify the entirety of air in the indoor area. Here, however, an air cleaner cannot remove moisture included in the air, so a separate dehumidifier is required to be provided.

Thus, recently, a dehumidification-type air cleaner in which a dehumidification function, added to an air cleaner to allow the air cleaner to simultaneously perform an air cleaning function and a dehumidification function has been actively developed.

However, the magnitudes of an air current force used during air purification and that of an air current force used during dehumidification are different, leading to a problem in relation to controlling an air current force in a dehumidification-type air cleaner.

In detail, when the air cleaning function is undertaken with the air current force used for dehumidification, air cleaning performance of the dehumidification-type air cleaner is degraded, while in the case that the dehumidification function is undertaken with the air current force used for air cleaning, the dehumidification function is not properly implemented, degrading reliability of the dehumidification-type air cleaner.

An aspect of the present invention provides an air current force control method and a dehumidification-type air cleaner using the same.

According to an aspect of the present invention, there is provided a method for controlling an air current force of a dehumidification-type air cleaner, including: an air purification operation of setting a rotational speed of a intake fan according to a pre-set purification mode and filtering out contaminants from external air introduced according to a rotation of the intake fan; a dehumidification operation signal input operation of receiving a dehumidification operation signal for operating a dehumidifying unit to remove vapor included in the external air; a dehumidifying operation of resetting the rotational speed of the intake fan according to the dehumidification operation signal when the purification mode is a general purification mode, and operating the dehumidifying unit to perform a dehumidification operation; and a function purification operation of maintaining the rotational speed of the intake fan when the purification mode is a function purification mode and not performing the dehumidifying operation.

In the dehumidification operation signal input operation, when humidity of the external air is equal to or greater than a reference humidity value, the dehumidification operation signal may be received.

In the dehumidifying operation, the rotational speed of the intake fan may be reset to a pre-set dehumidification operational speed according to the humidity value of the external air.

The method may further include: an air purification returning operation of resetting the rotational speed of the intake fan to a pre-set purification driving speed according to the amount of contaminants in the external air measured by a dust sensor, when the humidity of the external air falls to below the reference humidity value.

The method may further include: a sleep mode changing operation of measuring an external illumination value (i.e., a value of intensity of illumination or an illuminance value), stopping the operation of the dehumidifying unit, entering a sleep mode, and resetting the rotational speed of the intake fan to a noiseless speed, when the measured illumination value is lower than a reference illumination value.

The method may further include: a laundry drying operation of increasing the rotational speed of the intake fan to a laundry drying operational speed, while operating the dehumidifying unit, when a laundry drying signal is input.

According to another aspect of the present invention, there is provided a dehumidification-type air cleaner including: a filter unit filtering out contaminants included in the air introduced thereinto; a dehumidifying unit removing vapor included in the introduced air; an intake fan rotated by a motor to allow external air to be introduced into the dehumidification-type air cleaner; and a controller operating the dehumidification-type air cleaner in a purification mode in which the contaminants are filtered out by adjusting a rotational speed of the intake fan without driving the dehumidifying unit, and determining whether to operate the dehumidifying unit and resetting the rotational speed of the intake fan according to a type of the purification mode, when a dehumidification operation signal for operating the dehumidifying unit is input.

When humidity of the external air is equal to or greater than a reference humidity value, the controller may receive the dehumidification operation signal.

When the purification mode is a general purification mode, the controller may set the operation of the dehumidifying unit and the rotational speed of the intake fan according to the dehumidification operation signal, and when the purification mode is a function purification mode, the controller may maintain the operation according to the function purification mode.

The controller may receive an external illumination value, and when the received illumination value is lower than a pre-set value, the controller may stop the operation of the dehumidifying unit and operate the dehumidification-type air cleaner in a sleep mode.

When a laundry drying signal is input, the controller may operate the dehumidifying unit and simultaneously increase the rotational speed of the intake fan to a laundry drying speed.

According to another aspect of the present invention, there is provided a dehumidification-type air cleaner including: a filter unit filtering out contaminants included in the air introduced thereinto; a dehumidifying unit removing vapor included in the introduced air; an intake fan rotated by a motor to allow external air to be introduced into the dehumidification-type air cleaner; a sensor unit including an illumination sensor measuring an illumination value, a humidity sensor measuring a humidity value of the air, and measuring an amount of dust in the air; and a controller controlling the intake fan to operate at multiple revolution per minute (RPM) speeds set in proportion to humidity values and amounts of dust, wherein the controller measures an illumination value, a humidity value, and an amount of dust, and when the measured illumination values are equal to or greater than a reference illumination used for determining daytime and nighttime, the controller controls the intake fan to operate at multiple RPM speeds in proportion to the measured humidity values, and when the measured illumination value is lower than a reference illumination, the controller controls the intake fan to operate at the lowest RPM speed based on the measured humidity value and a reference humidity.

In the case in which the controller controls the intake fan to operate at the lowest RPM speed, when the measured humidity value is equal to or greater than the pre-set reference humidity, the controller controls the intake fan to operate at the lowest RPM speed among the multiple RPM speeds set in proportion to the humidity values, and when the measured humidity value is lower than the reference humidity, the controller may control the intake fan to operate at the lowest RPM speed among the multiple RPM speeds set in proportion to the amounts of dust.

The controller may drive the intake fan during a certain period of time after the RPM controlling of the intake fan according to the comparison results is terminated.

The filter unit may include a first filter unit removing large dust particles from the air and a second filter unit including a high efficiency particulate arresting air (HEPA) filter removing fine dust particles and microorganisms and a deodorization filter removing odors from the air.

The dehumidifying unit may include an evaporator evaporating a liquid refrigerant; a compressor compressing a gaseous refrigerant evaporated from the evaporator; and a condenser condensing the refrigerant compressed by the compressor and recirculating the condensed refrigerant to the evaporator.

The condenser and the evaporator may be disposed to be spaced apart from one another on a path along which air introduced by the intake fan is expelled.

The condenser and the evaporator may be disposed on the same plane, perpendicular to the path along which the air introduced by the intake fan is expelled.

The filter unit may be disposed in a forward portion of the dehumidifying unit on the path along which the air introduced by the intake fan is expelled.

The first filter unit and the second filter unit may be separately disposed on the path along which the air introduced by the intake fan is expelled, such that the first filter unit is disposed in a forward portion of the dehumidifying unit and the second filter unit is disposed at a rear stage of the dehumidifying unit.

The deodorization filter may be disposed in a forward portion of the HEPA filter on the path along which the air introduced by the intake fan is expelled.

The first filter unit may be disposed in a forward portion of the dehumidifying unit and the second filter unit may be disposed at a rear stage of the dehumidifying unit on the path along which the air introduced by the intake fan is expelled.

According to another aspect of the present invention, there is provided a method for controlling a dehumidification-type air cleaner including a filter unit filtering out contaminants included in the air introduced thereinto, a dehumidifying unit removing vapor included in the introduced air, an intake fan rotated by a motor to allow external air to be introduced into the dehumidification-type air cleaner, a sensor unit including an illumination sensor measuring an illumination value, a humidity sensor measuring a humidity value of the air, and measuring an amount of dust in the air, and a controller controlling the intake fan to operate at multiple revolution per minute (RPM) speeds set in proportion to humidity values and amounts of dust, including: measuring the illumination value, the humidity value, and the amount of dust; comparing the measured illumination value with a reference illumination used as a reference for determining daytime and nighttime; when the measured illumination value is equal to or greater than the reference illumination according to the comparison results, controlling the intake fan to operate at multiple RPM speeds in proportion to the measured humidity value; and when the measured illumination value is lower than the reference illumination according to the comparison results, controlling the intake fan to operate at the lowest RPM speed based on the measured humidity value and a pre-set reference humidity.

The controlling of the intake fan to operate at the lowest RPM speed may include: comparing the measured humidity value with the reference humidity; and when the measured humidity value is equal to or greater than the reference humidity according to the comparison results, controlling the intake fan to operate at the lowest RPM speed among the multiple RPM speeds set in proportion to the humidity values, and when the measured humidity value is lower than the reference humidity, controlling the intake fan to operate at the lowest RPM speed among the multiple RPM speeds set in proportion to the amounts of dust.

The method may further include driving the intake fan during a certain period of time after the RPM controlling of the intake fan according to the comparison results is terminated.

In the case of the dehumidification-type air cleaner and the control method thereof according to an embodiment of the present invention, when a range of an air current force for air cleaning and that of an air current force for dehumidification are different, an air cleaning function and a dehumidification function can be effectively implemented according to respective circumstances, and reliability operation of the dehumidification-type air cleaner can be implemented.

Also, with the dehumidification-type air cleaner and the control method thereof according to an embodiment of the present invention, since the dehumidification-type air cleaner can operate in a sleep mode in which noise generation is minimized, a user may not experience interruptions therefrom when sleeping. Namely, noise can be reduced according to a surrounding environment, e.g., at nighttime, a time in which the sleep mode is applied by appropriately controlling an RPM of a intake fan according to an illumination value (i.e., a value of intensity of illumination or an illuminance value), thus maintaining an agreeable, comfortable indoor environment.

In addition, in the case of the dehumidification-type air cleaner and the control method thereof, according to an embodiment of the present invention, an excellent laundry (or clothes) drying function can be provided by providing a large air current force.

In addition, in the case of the dehumidification-type air cleaner and the control method thereof according to an embodiment of the present invention, since a high efficiency particulate arresting air (HEPA) filter and a deodorization filter are disposed in a rear end portion of a dehumidification module, a degradation in the performance and shortening of the lifespan of both the HEPA filter and the deodorization filter can be prevented.

In addition, in the case of the dehumidification-type air cleaner and the control method thereof according to an embodiment of the present invention, frost generated on an evaporator can be effectively removed by adjusting a driving speed of the intake fan without an additional component.

In addition, in the case of the dehumidification-type air cleaner and the control method thereof according to an embodiment of the present invention, a dehumidifying unit can be quickly, effectively dried in consideration of humidity and dehumidifying unit temperature.

In addition, in the case of the dehumidification-type air cleaner and the control method thereof according to an embodiment of the present invention, the dehumidification function can be stably provided even in a high-temperature environment such as that of summer, and an overload generated in the dehumidification-type air cleaner can be relieved without any additional configuration.

In addition, in the case of the dehumidification-type air cleaner and the control method thereof according to an embodiment of the present invention, noise and vibrations cannot be abruptly generated during a dehumidifying operation of the dehumidification-type air cleaner. Thus, a user can be prevented from being startled otherwise by noise and vibrations, and the user can have confidence in the performance of the dehumidification-type air cleaner and whether or not the dehumidification-type air cleaner is operating normally. Also, since the user has confidence in the operation of the dehumidification-type air cleaner, user satisfaction can be increased.

FIG. 1 is a schematic view illustrating a dehumidification-type air cleaner according to a first embodiment of the present invention;

FIG. 2 is a schematic view illustrating a dehumidification-type air cleaner according to a second embodiment of the present invention;

FIG. 3 is a schematic view illustrating a dehumidification-type air cleaner according to a third embodiment of the present invention;

FIG. 4 is a schematic view illustrating a dehumidification-type air cleaner according to a fourth embodiment of the present invention;

FIG. 5 is a flow chart illustrating a process of a method of controlling a dehumidification-type air cleaner according to an embodiment of the present invention;

FIG. 6 is a flow chart illustrating a process of a method of controlling a dehumidification-type air cleaner according to another embodiment of the present invention;

FIG. 7 is a flow chart illustrating a process of a method of controlling a dehumidification-type air cleaner according to another embodiment of the present invention;

FIG. 8 is a flow chart illustrating a process of a method of controlling an air current force of a dehumidification-type air cleaner according to an embodiment of the present invention;

FIG. 9 is a flow chart illustrating a process of a method of defrosting a dehumidification-type air cleaner according to an embodiment of the present invention;

FIG. 10 is a flow chart illustrating a process of a method of drying a heat exchanger of a dehumidification-type air cleaner according to an embodiment of the present invention;

FIG. 11 is a flow chart illustrating a process of a method of drying a heat exchanger of a dehumidification-type air cleaner according to another embodiment of the present invention;

FIG. 12 is a flow chart illustrating a process of a method of controlling an overload of a dehumidification-type air cleaner according to an embodiment of the present invention; and

FIG. 13 is a flow chart illustrating a process of controlling reducing of noise of a compressor of a dehumidification-type air cleaner according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. In describing the present invention, if a detailed explanation for a related known function or construction is considered to unnecessarily divert from the gist of the present invention, such explanation will be omitted but would be readily understood by those skilled in the art. In the drawings, the shapes and dimensions of elements may be exaggerated for clarity, and the same reference numerals will be used throughout to designate the same or like components.

It will be understood that when an element is referred to as being "connected to" another element, it can be directly connected to the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly connected to" another element, there are no intervening elements present. In addition, unless explicitly described to the contrary, the word "comprise" and variations such as "comprises" or "comprising", will be understood to imply the inclusion of stated elements but not the exclusion of any other elements.

FIG. 1 is a schematic view illustrating a dehumidification-type air cleaner according to a first embodiment of the present invention.

With reference to FIG. 1, a dehumidification-type air cleaner 100 according to an embodiment of the present invention may include a filter unit 110, a dehumidifying unit 120, an intake fan 130, sensor units S1, S2, and S3, and a controller 140. Here, a path P illustrated in FIG. 1 denotes a path of air introduced into the dehumidification-type air cleaner 100. The introduced air may sequentially pass through the filter unit 110 and the dehumidifying unit 120.

The dehumidification-type air cleaner 100 according to an embodiment of the present invention will be described with reference to FIG. 1.

The filter unit 110 may filter out contaminants included in the air introduced thereto. The filter unit 110 may remove the contaminants such that it adsorbs contaminants in the air introduced by the intake fan 130.

The filter unit 110 may be divided into

first filter units

111 and 112 and

second filter units

113 and 114. The respective filter units may include a plurality of filters.

In detail, the

first filter units

111 and 112 may include a pre-filter 111, a functional filter 112, and the like, and the

second filter units

113 and 114 may include a high efficiency particulate arresting air (HEPA) filter 113, a deodorization filter 114, and the like.

The pre-filter 111 may serve to remove relatively large dust motes, pet hair, or the like, and the functional filter 112 may serve to remove pollen, rat mites, harmful microorganisms, bacteria, yellow dust, and the like. Here, the functional filter may perform various additional functions besides the function of filtering out contaminants included in the air, and may include a vitamin filter introducing a vitamin component to expelled air, or the like.

Besides, the filter unit 110 may include various types of filters and is not limited to the number of filters illustrated in FIG. 1.

The dehumidifying unit 120 may remove vapor included in the introduced air. The dehumidifying unit 120 may employ a cooling scheme of cooling introduced air too reduce an amount of vapor that may be included therein.

In detail, the dehumidifying unit 120 may include an evaporator evaporating a liquid refrigerant, a compressor 122 compressing a gaseous refrigerant evaporated by the evaporator 121, and a condenser 123 condensing the refrigerant compressed by the compressor 122 to re-circulate it to the evaporator 121, and adjust humidity in the introduced air.

As for an operational principle of the dehumidifying unit 120, as the evaporator 121 evaporates a liquid refrigerant into a gaseous refrigerant, ambient heat is absorbed to cool ambient air, and the compressor 122 intakes the gaseous refrigerant evaporated by the evaporator 121 and increases the refrigerant to saturation pressure and expels the same. Thus, as the refrigerant passes through the compressor 122, the refrigerant may be changed to have a high temperature and high pressure. Also, the condenser 123 allows the high temperature and high pressure refrigerant, which has been compressed by the compressor 122, to be heat-exchanged with ambient air having a relatively low temperature and condensed to have a room temperature and high pressure so as to be re-liquefied. Thus, the liquefied refrigerant is supercooled to have a temperature lower than a normal condensation temperature and expelled from the condenser 123.

Meanwhile, the liquid refrigerant expelled from the condenser 123 passes through an expansion valve (not shown) to have a low pressure so as to be in a state in which evaporation may easily occur, and the low pressure liquid refrigerant is re-circulated to the evaporator 121 to cool air around the evaporator 121. In this process, vapor included in the air is condensed (or congeals) on a surface of the evaporator 121 and is discharged through a drain hose (not shown) to lower humidity in the air. In this manner, by the dehumidifying unit 120 comprised of the evaporator 121, the compressor 122, and the condenser 123, air is expelled to an indoor area through the evaporator 121 and the condenser 123, and the indoor air is reintroduced to the evaporator 121, and this circulation process is repeatedly performed to dehumidify the indoor area. Here, the compressor 122 may compress the refrigerant by using an electric motor, and the compressor, namely, the operation of the electric motor, may be controlled by the controller 140.

The intake fan 130 is rotated by a motor to introduce external air into the interior of the dehumidification-type air cleaner 100. In detail, as illustrated, air introduced by the intake fan 130 passes through the filter unit 110 and the dehumidifying unit 120. The motor rotating the intake fan 130 may be a further motor, different from the electric motor operating the compressor 122. A rotational speed (or rotational velocity) of the intake fan 130 may be controlled by the controller 140, and an amount of external air introduced into the dehumidification-type air cleaner 100 may vary according to the rotational speed.

The dehumidification-type air cleaner 100 may operate in a purification mode in which contaminants in the air are removed by using the filter unit 110 without using the dehumidifying unit 120 or in a dehumidification mode in which vapor in the air is removed by using the dehumidifying unit 120. Here, the rotational speed of the intake fan 130 may vary according to the mode of the dehumidification-type air cleaner 100, and in particular, when the dehumidification-type air cleaner 100 operates in the purification mode, it may operate at a rotational speed higher than that at which the dehumidification-type air cleaner 100 operates in the general dehumidification mode.

For example, a rotational speed of the intake fan 130 in the purification mode may be set to be within a range about 300 rpm to 1000 rpm, and the intake fan 130 may have a rotational speed ranging from 400 rpm to 650 rpm. Dehumidification capability of the dehumidifying unit 120 may vary according to an amount of external air supplied to the dehumidifying unit 120, and if an excessively small or excessively large amount of external air is supplied to the dehumidifying unit 120, the dehumidification capability of the dehumidifying unit 120 may be drastically degraded. Thus, when the dehumidification-type air cleaner 100 operates in the dehumidification mode, the rotational speed of the intake fan 130 may be set to be within a range narrower than that of the purification mode.

The purification mode may include a normal purification mode in which a rotational speed of the intake fan 130 is set according to an air current force (or air volume) requested by a user and contaminants in the air introduced by the intake fan 130 are removed by the filter unit 110 and a functional purification mode in which the intake fan 130 is operated according to a rotational speed of the intake fan 130 set according to respective functions to perform the respective functions. The functional purification mode may include, for example, a yellow dust mode, a laundry drying mode, a nighttime sleep mode, and the like.

In the case of the yellow dust mode, the rotational speed of the intake fan 130 may be set to quickly remove yellow dust introduced into an indoor area and toxic substances such as various heavy metals, harmful microorganisms, and the like, included in the yellow dust. Namely, in the case of the yellow dust mode, the rotational speed of the intake fan 130 is set to be high so as to quickly remove the contaminants. Conversely, the nighttime sleep mode is a mode requiring silence with respect to the dehumidification-type air cleaner 100 for the user, so the intake fan 130 is set to have a low rotational speed so as to generate a small amount of noise according to the operation of the dehumidification-type air cleaner 100. Namely, for the respective functional purification modes, the rotational speeds of the intake fan 130 may be appropriately set beforehand, according to the foregoing respective functions.

Also, the dehumidification-type air cleaner 100 may be operated in an automatic mode. Namely, when humidity in the air exceeds a reference level of humidity (e.g., 50%) while the dehumidification-type air cleaner 100 is operating in the purification mode, the dehumidification-type air cleaner 100 may be changed to operate in the dehumidification mode, and thereafter, when humidity is drops below the reference level of humidity, according to the dehumidification operation of the dehumidifying unit 120, the dehumidification-type air cleaner 100 may be changed to operate in the purification mode.

Besides, the speed of resolution of the intake fan 130 may be controlled according to respective functions performed by the controller 140. In detail, the rotational speed may be set in relation to air current force controlling, defrosting, heat-exchanger drying, overload controlling, and compressor start noise reduction controlling. A specific algorithm for setting the speeds of resolution of the intake fan 130 according to the respective functions will later be described.

The sensor units S1, S2, and S3 may include a humidity sensor S1 measuring a humidity value of air, a dust sensor S2 measuring an amount of dust in the air, and an illumination sensor S3 measuring an illumination value. The measured humidity value, amount of dust, and illumination value may be delivered to the controller 140. Although not shown, the sensor units may further include a sensor measuring a surface temperature and humidity of the evaporator 121. Besides, various types of sensors may be further included in the sensor units.

The controller 140 may adjust the speed of resolution of the intake fan 130 according to various functions desired to be executed, and in order to adjust the rotational speed, the controller 140 may receive a humidity value, an amount of dust, an illumination value, and the like, from the sensor units. In detail, the controller 140 may perform various functions such as air current force controlling, defrosting, heat-exchange drying, overload controlling, compressor start noise reduction controlling, and the like, and a specific control algorithm of the controller 140 will be described later.

According to the foregoing configuration as shown in FIG. 1, the filter unit 110 and the dehumidifying unit 120 are separated, so the dehumidification-type air cleaner 100 has a technical effect that it can be easily assembled and managed. In addition, since the HEPA filter 113 is positioned at a front stage of the dehumidifying unit 120 in the path P, an accumulation of dust in the

heat exchangers

121 and 123 of the dehumidifying unit 120 can be prevented.

FIG. 2 is a schematic view illustrating a dehumidification-type air cleaner according to a second embodiment of the present invention. With reference to FIG. 2, unlike the dehumidification-type air cleaner 100, a dehumidification-type air cleaner 200 according to the second embodiment of the present invention has a structure in which a first filter unit 110A and a second filter unit 110B are separated, based on the dehumidifying unit 120. Thus, air introduced by the intake fan 130 sequentially passes through the first filter unit 110A, the dehumidifying unit 120, and the second filter unit 110B as indicated by the path P. In particular, since the deodorization filter 114 is disposed at a rear stage of the dehumidifying unit 120 as shown in the path P, air can be discharged after an odor according to the

heat exchanges

121 and 123 of the dehumidifying unit 120 is removed. Thus, in comparison to the dehumidification-type air cleaner 100 of FIG. 1, more agreeable indoor air can be obtained through the dehumidification-type air cleaner 200. Also, since the deodorization filter 114 is disposed in front of the HEPA filter 113 as shown in the path P, permeation of the HEPA filter 113 by an odor can be prevented. In addition, since the HEPA filter 113 is disposed at a rear stage of the dehumidifying unit 120, dehumidified dry air can pass through the HEPA filter 113, obtaining a technical effect of preventing a degradation in performance of the HEPA filter 113, especially during summer.

FIG. 3 is a schematic view illustrating a dehumidification-type air cleaner according to a third embodiment of the present invention. Unlike the dehumidification-type air cleaner 200 of FIG. 2, a dehumidification-type air cleaner 300 of FIG. 3 has a structure in which the

heat exchangers

121 and 130 of the dehumidifying unit 120 are disposed on a plane perpendicular to that of the path P along which air introduced by the intake fan 130 is discharged. Meanwhile, like the dehumidification-type air cleaner 200 of FIG. 2, the first filter unit 110A and the second filter unit 110B are separated based on the dehumidifying unit 120, obtaining the same advantages as those described above with reference to FIG. 2.

FIG. 4 is a schematic view illustrating a dehumidification-type air cleaner according to a fourth embodiment of the present invention. Unlike the dehumidification-type air cleaner 100 of FIG. 1, a dehumidification-type air cleaner 400 of FIG. 4 has a structure in which the condenser 121 and the evaporator 123 of the dehumidifying unit 120 are disposed on a plane perpendicular to that of the path P along which air introduced by the intake fan 130 is discharged. Meanwhile, like the dehumidification-type air cleaner 100 of FIG. 1, the first filter unit 110 including both the first filter unit 110A and the second filter unit 110B are disposed at a front stage of the dehumidifying unit 120, obtaining the same advantages as those described above with reference to FIG. 1.

FIG. 5 is a flow chart illustrating a process of a method of controlling a dehumidification-type air cleaner according to an embodiment of the present invention, in which, in particular, the dehumidification-type air cleaner is controlled by using an illumination value measured by the illumination sensor S3. Of course, the control method described with reference to FIG. 5 may be applied to all of the apparatuses having the foregoing configurations illustrated in FIGS. 1 through 4.

With reference to FIGS. 1 through 5, first, the sensor units S1, S2, and S3 measure an illumination value L0, a humidity value H0, and an amount of dust D0 (S500). The measured illumination value L0, humidity value H0, and amount of dust D0 are delivered to the controller 140.

Next, the controller 140 compares the measured illumination value L0 with a reference illumination L1 (S501). When the measured illumination value L0 is equal to or greater than the reference illumination L1 according to the comparison results, the controller 140 determines that it is daytime and performs step S502, while in the case that the measured illumination value L0 is lower than the reference illumination L1, the controller 140 determines that it is nighttime and performs step S505. Here, the reference illumination L1 is an illumination value as a reference used for determining daytime and nighttime.

In step S502, the controller 140 compares the measured humidity value H0 with a reference humidity H1. When the measured humidity value H0 is equal to or greater than the reference humidity H1 according to comparison results, the controller 140 determines that humidity is high and performs step S503, while in the case that the measured humidity value H0 is lower than the reference humidity H1, the controller 140 performs step S508.

Step S503 is performed when it is daytime and the intake fan 130 is controlled in an environment having a high level of humidity. In detail, the controller 140 may control the rotational speed of the intake fan 130 according to the measured humidity value H0 and the speed of the intake fan 130 may be controlled to have any one of pre-set RPM values. For example, when the measured humidity value H0 is higher than the reference humidity by 30% or more, the controller 140 controls the intake fan 130 to rotate at a revolution per minute (RPM) speed of R5. When the measured humidity value H0 is higher than the reference humidity by 20% to less than 30%, the controller 140 controls the intake fan 130 to rotate at a revolution per minute (RPM) speed of R6. When the measured humidity value H0 is higher than the reference humidity by 10% to less than 20%, the controller 140 controls the intake fan 130 to rotate at a revolution per minute (RPM) speed of R7. Here, relationships R5 > R6 > R7 may be established. In particular, after the controller 140 controls the intake fan 130 to rotate at a particular RPM (one of R5, R6, and R7), when a certain period of time, e.g., three seconds, has lapsed, the controller 140 may apply power to the compressor 122 of the dehumidifying unit 120 (S504). In this manner, since the certain period of time is provided (awaited) after the intake fan 130 is controlled, the dehumidifying unit 120 may be operated after the intake fan 130 is rotated at an RPM of a steady state.

In particular, when the intake fan 130 is first operated and the dehumidifying unit 120 is then operated, noise uniquely generated when the compressor 122 of the dehumidifying unit 120 starts can be buried in noise generated by the intake fan 130. Then, a problem in which the user is startled by abrupt noise and vibrations according to an operation of the compressor 122 can be prevented.

The foregoing humidity values (reference humidity levels 10%, 20%, and 30%) are merely illustrative and may be naturally changed according to an embodiment as necessary. Also, in another embodiment of the present invention, power may be first applied to the compressor 122 (S504) and the rotational speed of the intake fan 130 may then be controlled (S503).

Meanwhile, step S508 is performed when it is daytime and the intake fan 130 is controlled in an environment having a low level of humidity. In this case, the controller 140 turns off the power of the controller 122. The reason is because the dehumidifying unit 120 is not required to be operated because the measured humidity value H0 is lower than the reference humidity H1. Thus, in this case, the controller 140 performs an air purification operation by controlling the rotational speed of the intake fan 130 in proportion to the measured amount of dust D0 (S509). For example, when the measured amount of dust H0 is higher than a reference amount of dust D1, the controller 140 controls the intake fan 130 to rotate at an RPM of R1. As the measured amount of dust D0 is reduced at a relatively uniform ratio over the reference amount of dust D1, the controller 140 may control the intake fan 130 to rotate at a gradually reduced RPM such as from R2, R3, and R4. Here, relationships of R1 > R2 > R3 > R4 may be established.

Meanwhile, when the measured illumination value L0 is lower than a reference illumination L1 (e.g., nighttime), the controller 140 compares the measured humidity value H0 with the reference humidity H1 (S505). When the measured humidity value H0 is equal to or greater than the reference humidity H1 according to the comparison results, the controller 140 performs step S506, and when the measured humidity value H0 is smaller than the reference humidity H1, the controller 140 may perform step S507.

Step S506 may be performed when it is nighttime and the intake fan 130 is controlled in an environment having a high level of humidity. In this case, the controller 140 operates the dehumidifying unit 120 and controls the intake fan 130 to flow at the lowest RPM speed, i.e., R7, among multiple RPM speeds (R5 to R7) set according to humidity values. Namely, at nighttime, the user may sleep, so a dehumidifying operation may be performed in a sleep mode in which noise generated by the dehumidification-type air cleaner is minimized.

Step S507 is performed when it is nighttime and the intake fan 130 is controlled in an environment having a low level of humidity. The controller 140 may control the intake fan 130 to rotate at the lowest RPM speed, i.e., R4, among the multi-stage RPMs (R1 to R4) set according to the amounts of dust. Namely, an air cleaning operation is performed in a sleep mode in which noise generated according to a rotation of the intake fan 130 is minimized.

Meanwhile, even after the driving of the dehumidifying unit 120 is terminated, the controller 140 may control the intake fan 130 to be driven for a certain period of time. Namely, in order to dry the water remaining in the dehumidifying unit 120, external air may be supplied to the dehumidifying unit 120 by the intake fan 130 to accelerate evaporation of the remaining water. In detail, if the water remaining in the dehumidifying unit 120, such as the water remaining on a surface of the evaporator 121, or the like, after the dehumidifying operation is not removed, harmful microorganisms, mold, or the like, may propagate to contaminate the interior of the dehumidification-type air cleaner and generate a disagreeable odor, or the like. Thus, the controller 140 may drive the intake fan 130 for a certain period of time even after the operation of the dehumidifying unit 120 is terminated, in order to remove the water remaining in the dehumidifying unit 120.

As described above, even when the measured humidity value H0 is high, if the measured illumination value L0 is smaller than the reference illumination L1, the intake fan 130 is controlled to rotate at the lowest RPM speed in an environment such as, for example, nighttime, thus reducing noise and maintaining an agreeable and comfortable indoor environment.

FIG. 6 is a flow chart illustrating a process of a method of controlling a dehumidification-type air cleaner according to another embodiment of the present invention, in which the dehumidification-type air cleaner is operated to execute only a dehumidification function. Of course, the control method described with reference to FIG. 6 may be applied to all of the apparatuses having the foregoing configurations illustrated in FIGS. 1 through 4

With reference to FIG. 6, first, the sensor units S1, S2, and S3 measure an illumination value L0 and a humidity value H0 (S600). The measured illumination value L0 and humidity value H0 are delivered to the controller 140.

Next, the controller 140 compares the measured illumination value L0 with the reference illumination L1 (S601). When the measured illumination value L0 is equal to or greater than the reference illumination L1 according to the comparison results, the controller 140 determines that it is daytime and performs step S602, while in the case that the measured illumination value L0 is lower than the reference illumination L1, the controller 140 performs step S610. Here, the reference illumination L1 is an illumination value as a reference used for determining daytime and nighttime.

In step S602, the controller 140 compares the measured humidity value H0 with a reference humidity H1. When the measured humidity value H0 is equal to or greater than the reference humidity H1 according to comparison results, the controller 140 determines that humidity is high and performs step S603, while in the case that the measured humidity value H0 is lower than the reference humidity H1, the controller 140 performs step S620.

Step S603 is performed when it is daytime and the intake fan 130 is controlled in an environment having a high level of humidity. In detail, the controller 140 may control the intake fan 130 to rotate at multiple stages of RPM (R5 to R7) according to the measured humidity value H0. For example, when the measured humidity value H0 is higher than the reference humidity by 30% or more, the controller 140 controls the intake fan 130 to rotate at a revolution per minute (RPM) speed of R5. When the measured humidity value H0 is higher than the reference humidity by 20% to 30% or below, the controller 140 controls the intake fan 130 to rotate at a revolution per minute (RPM) speed of R6. When the measured humidity value H0 is higher than the reference humidity by 10% to 20% below, the controller 140 controls the intake fan 130 to rotate at a revolution per minute (RPM) speed of R7. Here, relationship R5 > R6 > R7 may be established. In particular, after the controller 140 controls the intake fan 130 to rotate at a particular RPM speed (one of R5, R6, and R7), when a certain period of time, e.g., three seconds, has lapsed, the controller 140 may apply power to the compressor 122 of the dehumidifying unit 120 (S604). In this manner, since the certain period of time is provided (awaited) after the intake fan 130 is controlled, the dehumidifying unit 120 may be operated after the intake fan 130 is rotated at the RPM of a steady state. The foregoing humidity values (reference humidity levels 10%, 20%, and 30%) are merely examples and may be changed according to an embodiment as necessary.

Meanwhile, step S620 is performed when it is daytime and the intake fan 130 is controlled in an environment having a low level of humidity. In this case, the controller 140 turns off the power of the controller 122. The reason for this is because the dehumidifying unit 120 is not required to be operated because the measured humidity value H0 is lower than the reference humidity H1.

Meanwhile, when the measured illumination value L0 is lower than a reference illumination L1 (e.g., nighttime), the controller 140 compares the measured humidity value H0 with the reference humidity H1 (S610). When the measured humidity value H0 is equal to or greater than the reference humidity H1 according to the comparison results, the controller 140 performs step S611, and when the measured humidity value H0 is smaller than the reference humidity H1, the controller 140 may perform step S612.

Step S611 may be performed when it is nighttime and the intake fan 130 is controlled in an environment having a high level of humidity. In this case, the controller 140 may control the intake fan 130 to rotate at the lowest amount of RPMs, i.e., R7, among the multiple RPM speeds (R5 to R7) set with respect to humidity values.

Similarly, step S612 is performed when it is nighttime and the intake fan 130 is controlled in an environment having a low level of humidity. In this case, the controller 140 turns off the power of the controller 122. The reason is because the dehumidifying unit 120 is not required to be operated because the measured humidity value H0 is lower than the reference humidity H1.

Meanwhile, even after the operation of the dehumidifying unit 120 is terminated, the controller 140 may control the intake fan 130 to be driven for a certain period of time. Through such controlling, an effect of drying the water remaining in the dehumidifying unit 120 can be obtained.

FIG. 7 is a flow chart illustrating a process of a method of controlling a dehumidification-type air cleaner according to another embodiment of the present invention, in which the dehumidification-type air cleaner is operated to execute only an air purification function. Of course, the control method described with reference to FIG. 7 may be applied to all of the apparatuses having the foregoing configurations illustrated in FIGS. 1 through 4

With reference to FIG. 7, first, the sensor units S1, S2, and S3 measure an illumination value L0 and an amount of dust D0 (S700). The measured illumination value L0 and amount of dust D0 are delivered to the controller 140.

Next, the controller 140 compares the measured illumination value L0 with the reference illumination L1 (S701). When the measured illumination value L0 is equal to or greater than the reference illumination L1 according to the comparison results, the controller 140 determines that it is daytime and performs step S702, while in the case that the measured illumination value L0 is lower than the reference illumination L1, the controller 140 performs step S704. Here, the reference illumination L1 is an illumination value used as a reference for determining daytime and nighttime.

In step S702, the controller 140 compares the measured amount of dust D0 with a reference amount of dust D1. When the measured amount of dust D0 is equal to or greater than the reference amount of dust D1 according to comparison results, the controller 140 determines that amount of dust is large and performs step S703, while in the case that the measured amount of dust D0 is lower than the reference amount of dust D1, the controller 140 terminates the process.

Step S703 is performed when it is daytime and the intake fan 130 is controlled in an environment having a large amount of dust. In detail, the controller 140 controls the intake fan 130 to rotate at multiple RPM speeds (R1 to R4) according to the measured amount of dust D0. For example, when the measured amount of dust D0 is larger than the reference amount of dust D1, the controller 140 controls the intake fan 130 to rotate at the RPM of R1. Similarly, as the measured amount of dust D0 is reduced at a relatively uniform ratio over the reference amount of dust D1, the controller 140 may control the intake fan 130 to rotate at a gradually reduced RPM such as from R2, R3, and R4. Here, relationships of R1 > R2 > R3 > R4 may be established.

Step 704 is performed when it is nighttime and the intake fan 130 is controlled in an environment in which the measured amount of dust D0 is smaller than the reference amount of dust D1. In this case, the controller may control the intake fan 130 to rotate at the lowest RPM speed, i.e., R4, among the multiple RPM speeds (R1 to R4) set with respect to the amounts of dust.

As described above, according to an embodiment of the present invention, by appropriately controlling the RPM of the intake fan 130 according to an illumination value, noise can be reduced according to a surrounding environment, e.g., at nighttime during which a sleep mode is applied, obtaining a technical effect of maintaining an agreeable, comfortable environment. Also, according to another embodiment of the present invention, the foregoing control methods can be applicable to apparatuses having various structures, and in particular, since the HEPA filter and the deodorization filter are disposed at a rear stage of the dehumidifying unit, a degradation in the performance and shortening of the lifespan of the HEPA filter and the deodorization filter can be prevented.

Meanwhile, the controller 140 may perform various functions including the foregoing functions. In detail, the controller 140 may execute functions such as air current force controlling, defrosting, heat exchanger drying, overload controlling, compressor start noise reduction controlling, and the like. Hereinafter, an operation of the controller 140 for performing the foregoing respective functions will be described in detail.

First, air current force controlling will be described.

While the dehydration type air cleaner is being operated in the purification mode in which contaminants are filtered out by adjusting a rotational speed of the intake fan 130 without driving the dehumidifying unit 120, when a dehumidification operation signal for operating the dehumidifying unit 120 is input, the controller 140 may determine whether to operate the dehumidifying unit 120 or reset the rotational speed of the intake fan 130. Namely, in the case of the dehumidification-type air cleaner operating in the purification mode, if the humidity of external air is higher than a reference humidity value, or according to a user input, a dehumidification operation signal for operating the dehumidifying unit 120 may be input to the controller 140.

As described above, the operation range of the rotational speed of the intake fan 130 of the dehumidification-type air cleaner is larger than that of the rotational speed of a general dehumidification device. Thus, when the dehumidification-type air cleaner is operated in the purification mode, the rotational speed of the intake fan 130 may be outside the range of the rotational speed of the dehumidification device. In this case, whether to adjust the rotational speed of the intake fan 130 to a speed previously set in the purification mode or whether to adjust the rotational speed of the intake fan 130 according to the dehumidification operation signal may be a question.

If the rotational speed of the intake fan 130 is adjusted to the speed previously set in the purification mode, the rotational speed of the intake fan 130 is sufficiently fast to drastically degrade the dehumidification effect of the dehumidifying unit 120, and conversely, if the rotational speed of the intake fan 130 is set according to the dehumidification operation signal, the rotational speed of the intake fan 130 is changed, especially in the functional purification mode, potentially resulting in a failure of obtaining an effect intended through the functional purification mode.

In order to prevent this, the purification mode is divided into a general purification mode and a functional purification mode, and in the case of the general purification mode, the controller 140 may set the operation of the dehumidifying unit 120 and the rotational speed of the intake fan 130 according to the dehumidification operation signal, and when the purification mode is the functional purification mode, the controller 140 may maintain an operation according to the functional purification mode.

The general purification mode may be a mode in which air purification is performed on air introduced based on an air current force set by the user, and so on, and in this mode, any additional function or effect cannot be expected in the case of the air current force set by the user. Also, the input of the dehumidification operation signal means that a dehumidification operation is currently required to be performed, so the dehumidification function may be preferentially performed. Thus, when the dehumidification operation is input while the dehumidification-type air cleaner is being operated, the dehumidification function may be performed by using the dehumidifying unit 120, and the operational speed of the intake fan 130 may be reset to a dehumidification operational speed according to the dehumidification operation signal.

Meanwhile, the functional purification mode is a mode for executing pre-set functions (a yellow dust mode, a laundry drying mode, a sleep mode, and the like), and the rotational speed and a corresponding air current force of the intake fan 130 are essential to perform each function. Thus, in the functional purification mode, the rotational speed of the intake fan 130 set in the functional purification mode may be maintained as it is in spite of the dehumidification operation signal.

Also, in relation to the operation of the dehumidifying unit 120, the rotational speed of the intake fan 130 according to the dehumidification operation signal and that of the intake fan set in the functional purification mode are different. Thus, when the dehumidifying unit 20 is operated in the state of the rotational speed of the intake fan 130 set in the functional purification mode, a dehumidification effect of the dehumidifying unit 120 may be drastically degraded. This may reduce reliability of the dehumidification-type air cleaner for a user anticipating a dehumidification effect, so it may be configured such that the dehumidification function is not provided in the functional purification mode.

Here, after the dehumidification-type air cleaner enters the dehumidification mode, the humidity of external air may be reduced to below the reference humidity value according to the dehumidification operation. In this case, the controller 130 may stop the dehumidification operation and return to the purification mode, and in this case, the rotational speed of the intake fan 130 may be reset according to an amount of contaminants in the external air measured by the dust sensor S2.

In addition, the controller 140 may receive an external illumination value from the illumination sensor S3, and when the received illumination value is lower than a pre-set value, the controller 140 may operate the dehumidification-type air cleaner to enter the sleep mode, stopping the operation of the dehumidifying unit 120. Here, the controller 140 may receive an external illumination value measured by the illumination sensor S3 and recognize brightness of the outside of the dehumidification-type air cleaner.

When the external illumination value is lower than the pre-set value, the controller 140 determines that it is dark and operates the dehumidification-type air cleaner to a sleep mode. The sleep mode is a mode in which the dehumidification-type air cleaner is operated by minimizing noise generated by the dehumidification-type air cleaner. Here, the largest proportion of noise generated by the dehumidification-type air cleaner may be caused by noise resulting from the rotation of the intake fan 130 and a sound generated as a refrigerant is compressed by the compressor 122 of the dehumidifying unit 120 by using an electric motor.

Thus, when the dehumidification-type air cleaner is in the sleep mode, the controller 140 may stop the operation of the dehumidifying unit 120, specifically, the compressor 122, and may set the rotational speed of the intake fan 130 such that the intake fan 130 is operated at a speed lower than a pre-set noiseless speed.

Here, however, when the user directly inputs the dehumidification operation signal, although the external illumination value of the illumination sensor S3 is lower than the pre-set value, the dehumidification-type air cleaner may not be operated to the sleep mode. Namely, in this case, the controller 140 may operate the dehumidifying unit 120 to perform a dehumidification function according to a user intention to remove vapor from the air.

In detail, the dehumidification-type air cleaner may be operated in a manual mode in which the user directly inputs a dehumidification operation signal to make the dehumidification-type air cleaner perform a dehumidification operation and an automatic mode in which when the user inputs a target humidity, an indoor level of humidity is measured, and when the measured indoor level of humidity is higher than the target humidity, a dehumidification operation is automatically performed. Thus, when the dehumidification-type air cleaner is operated in the automatic mode, it may be changed to be operated in the sleep mode, while in the case that the dehumidification-type air cleaner is operated in the manual mode, the dehumidification-type air cleaner may perform a dehumidification function without being changed to the sleep mode.

A defrosting operation will hereinafter be described.

When the dehumidification-type air cleaner performs a dehumidification operation in a low temperature environment, vapor in the air condensed on the evaporator 121 may be frozen on the surface of the evaporator 121. Namely, the surface of the evaporator 121 may be frosted and a dehumidification capability of the evaporator 121 may be degraded.

In the related art, in order to remove the frost formed on the evaporator 121, the operation of the intake fan 130 is stopped and a hot refrigerant generated in the compressor 122 is directly bypassed to the evaporator 121. However, in order to directly bypass the hot refrigerant to the evaporator 121, an additional component is required, and an unfamiliar noise is generated in defrosting the evaporator 121 with a hot refrigerant, potentially causing the user (or the consumer) to mistake it for a fault, or the like.

Thus, in the present embodiment, the controller 130 may determine whether to change the dehumidification-type air cleaner to a defrosting mode for removing frost formed on the evaporator 121 (or defrosting the evaporator 121), and when the dehumidification-type air cleaner is changed to the defrosting mode, the controller 140 may cut off power of the compressor 122 and increase the rotational speed of the intake fan 130 to a defrosting driving speed, thus removing frost.

First, the controller 140 may receive a temperature signal from a temperature sensor that measures a surface temperature of the evaporator 121. When the received temperature signal is lower than a defrosting reference temperature, the controller 140 may change the dehumidification-type air cleaner to the defrosting mode. Here, when the temperature signal is maintained for a reference time duration or more below the defrosting reference temperature, the dehumidification-type air cleaner may be changed to the defrosting mode, or the dehumidification-type air cleaner may be repeatedly changed to the defrosting mode at pre-set periods to perform a defrosting operation. In addition, in general, whether to change the dehumidification-type air cleaner to the defrosting mode may be determined based on the temperature signal, and when the temperature signal is not input or when an input temperature signal is outside of a pre-set range, the dehumidification-type air cleaner may be changed to the defrosting mode at pre-set periods. Here, when the temperature signal is not input or when an input temperature signal is outside of a pre-set range, it may be determined that there is an error in the temperature sensor generating the temperature signal.

For example, when a surface temperature of the evaporator 121 measured by the temperature sensor which measures a surface temperature of the evaporator 121 is maintained at a temperature below a defrosting reference temperature (e.g., -1℃) for a reference time duration (e.g., 5 seconds) or more, the dehumidification-type air cleaner may be changed to the defrosting mode. Namely, when the evaporator 121 is maintained at a temperature lower than the defrosting reference temperature for a certain duration of time or more, vapor of external air liquefied in the evaporator 121 is frozen on the surface of the evaporator 121 to generate frost.

When the dehumidification-type air cleaner enters the defrosting mode, the controller 140 may cut off power of the compressor 122 to stop a phase change of the refrigerant. Without the phase change of the refrigerant, condensation of vapor on the evaporator 121 is stopped, thus preventing additional frosting on the evaporator 121.

Thereafter, the rotational speed of the intake fan 130 may be increased to a defrosting driving speed faster than the dehumidification operational speed used for the dehumidification operation. When the rotational speed of the intake fan 130 is increased, a large amount of external air may be introduced into the evaporator 121. Here, the external air may have a temperature higher than the surface temperature of the evaporator 121, transmitting heat to the evaporator 121, and frost may be frequently exposed to the external air supplied by the intake fan 130 so as to be immediately evaporated to form vapor. Accordingly, the temperature of the evaporator 121 is increased to defrost the surface of the evaporator 121 (namely, as the temperature of the evaporator 121 is increased, the frost formed on the surface of the evaporator 121 may disappear according to the increased temperature).

Thus, the defrosting function can be performed without the necessity of an additional component, and since the defrosting function is performed in a state in which the power of the compressor 122 is cut off, energy can be reduced. Also, in this case, since the defrosting is performed by increasing the rotational speed of the intake fan 130, noise according to the operation of the intake fan 130 is merely generated without other noise.

Thereafter, when the temperature signal becomes higher than the frosting reference temperature while the dehumidification-type air cleaner is being operated in the defrosting mode, the controller 140 may supply power to the compressor 122 and reduce the rotational speed of the intake fan 130 to the dehumidification operational speed. Namely, after the surface of the evaporator 121 is defrosted in the defrosting mode, the dehumidification-type air cleaner may be required to be operated again in the dehumidification mode in which humidity is removed from external air. Thus, when the surface temperature of the evaporator 121 measured by the temperature sensor is higher than the defrosting reference temperature, the dehumidification-type air cleaner may be changed from the defrosting mode to the dehumidification mode. Namely, the controller 140 may monitor the temperature of the evaporator 121 by using the temperature sensor, and when the temperature of the evaporator 121 is higher than the defrosting reference temperature, the controller 140 may determine that the frost formed on the evaporator 121 has been entirely removed, and return the dehumidification-type air cleaner again to the dehumidification mode.

In order to return the dehumidification-type air cleaner to the dehumidification mode, the controller 140 may supply power to the compressor 122 and reduce the rotational speed of the intake fan 130 to the dehumidification operational speed. When power is supplied to the compressor 122, a continuous phase change of the refrigerant may be resumed, and accordingly, air introduced into the evaporator 121 is cooled and vapor may be re-condensed. Also, in order to effectively remove vapor included in the air introduced into the evaporator 121, the rotational speed of the intake fan 130 may be reduced to the dehumidification operational speed.

A heat exchanger drying operation will hereinafter be described.

When the dehumidification operation of the dehumidification-type air cleaner is stopped, moisture remains in the

heat exchangers

121 and 123 of the dehumidifying unit 120. If the moisture remaining within the

heat exchangers

121 and 123 is not immediately removed, harmful microorganisms, mold, or the like, may propagate therein, and the interior of the

heat exchangers

121 and 122 may be contaminated by the propagation of harmful microorganisms, mold, or the like, and a disagreeable odor may be generated therein.

Thus, the controller 140 may determine whether to change the dehumidification-type air cleaner to a heat exchanger drying mode to remove the remaining moisture, especially in the

heat exchangers

121 and 123 of the dehumidifying unit 120. When the dehumidification-type air cleaner is changed to the heat exchanger drying mode, the controller 140 may control the operation of the intake fan 130 to provide external air to the

heat exchangers

121 and 123.

First, whether or not the dehumidification-type air cleaner is in the heat exchanger drying mode may be determined according to whether or not a control signal for stopping the operation of the compressor 122 is input to the controller 140.

The heat exchanger drying mode is an operation mode in which the

heat exchangers

121 and 123 are immediately dried to prevent propagation of harmful microorganisms, mold, or the like, in the dehumidifying unit 120 when the user stops the dehumidification function of the dehumidification-type air cleaner. Namely, the

heat exchangers

121 and 123 are dried at the same time when the dehumidification function is stopped, thereby preventing a generation of a disagreeable odor due to harmful microorganisms, mold, or the like, when the dehumidification-type air cleaner is driven again later. Thus, since the heat exchanger drying mode should be performed after the dehumidification function is stopped, it is required to recognize whether or not the dehumidification function has been stopped. In order to perform the dehumidification function, the refrigerant should be first compressed. Thus, whether or not the dehumidification function has been stopped may be recognized by determining whether or not the refrigerant has been compressed.

Thus, when the control signal for stopping the operation of the compressor 122 is input, the controller 140 determines that the dehumidification function has been stopped, and changes the dehumidification-type air cleaner to the heat exchanger drying mode.

Here, however, in the case of the dehumidification-type air cleaner, it may happen that the dehumidification operation is terminated and the dehumidification-type air cleaner is subsequently operated in the purification mode. Namely, the

heat exchangers

121 and 123 may be dried according to the rotation of the intake fan 130 used in the purification mode. Thus, the controller 140 may consider whether or not a control signal for stopping the operation of the intake fan 130 is input together with the control signal for stopping the operation of the compressor 122.

In addition, the controller 140 may receive the control signal for stopping the operation of the compressor 122 from a protection circuit, or the like, preventing an overload of the compressor 122, in addition to user input or a previously programmed operational time duration.

When the dehumidification-type air cleaner is changed to the heat exchanger drying mode, the controller 140 may set an operational speed and an operational time duration of the intake fan 130 according to a heat exchanger temperature value and a heat exchanger humidity value.

In detail, when the heat exchanger temperature value and the heat exchanger humidity value are higher than a reference temperature value and a reference humidity value, the controller 140 may set the intake fan 130 to operate at a first operational speed during a first operational time duration. Here, when the rotational speed of the intake fan 130 is divided into three speed levels, high, medium, and low, from fast to slow, the first operational speed may correspond to the medium speed level, and when the operational time duration of the intake fan 130 is divided into three stages of high, medium, and low from longer to shorter, the first operational time duration may correspond to the high stage. Namely, when the heat exchanger temperature value and the heat exchanger humidity value are high, the intake fan 130 may be operated at a fast rate for a long period of time to sufficiently dry the

heat exchangers

121 and 123.

Next, when the heat exchanger temperature value is lower than the reference temperature value but the heat exchanger humidity value is higher than the reference humidity value, the intake fan 130 may be set to operate at a second operational speed for a second operational time duration. Here, the second operational speed may correspond to the low speed level and the second operational time duration may correspond to the medium stage.

Finally, when the heat exchanger temperature value is lower than the reference temperature value and the heat exchanger humidity value is lower than the reference humidity value, the intake fan 130 may be set to operate at a third operational speed for a third operational time duration. Here, the third operational speed may correspond to the low speed level, like the second operational speed, and the third operational time duration may correspond to the low stage.

Here, a case in which the heat exchanger temperature value is higher than the reference temperature value but the heat exchanger humidity value is lower than the reference humidity value may also be considered. In this case, an operation of drying the

heat exchangers

121 and 123 may be omitted.

The controller 140 according to another embodiment of the present invention may set an operational speed and an operational time duration of the intake fan 130 with only the heat exchanger humidity value. Namely, the operational speed and the operational time duration of the intake fan 130 may be set by comparing the heat exchanger humidity value with a pre-set minimum humidity value and a pre-set maximum humidity value.

In detail, when the heat exchanger humidity value is greater than the pre-set maximum humidity value, the operational speed of the intake fan 130 may be set to the medium speed level and the operational time duration of the intake fan 130 may be set to the high stage to reliably remove a large amount of moisture existing in the

heat exchangers

121 and 123.

Also, when the heat exchanger humidity value is smaller than the pre-set maximum humidity value but greater than the pre-set minimum humidity value, the operational speed of the intake fan 130 may be set to the low speed level and the operational time duration of the intake fan 130 may be set to the medium stage. Namely, the operational speed and the operational time duration of the intake fan 130 are slightly lowered or reduced to effectively remove the humidity.

Finally, when the heat exchanger humidity value is greater smaller than the pre-set minimum humidity value, the operational speed of the intake fan 130 may be set to the low speed level and the operational time duration of the intake fan 130 may be set to the low stage to control the operation of the intake fan 130 according to the situation having a small level of humidity.

Overload controlling will hereinafter be described.

When a dehumidification operation is performed by using the dehumidifying unit 120, in particular, when a dehumidification operation is performed in a high temperature environment such as summer, heat-exchanging may not be smoothly performed in the

heat exchangers

121 and 123, potentially resulting in the compressor 122 being overheated and damaged, or the operation of the compressor 122 may be stopped. In order to prevent this, the controller 140 may determine whether to change the dehumidification-type air cleaner to an overload mode for resolving the overload applied to the dehumidifying unit 120. When the dehumidification-type air cleaner is changed to the overload mode, the controller 140 may increase the rotational speed of the intake fan 130 to an overload driving speed.

In detail, the controller 140 may determine whether to change the dehumidification-type air cleaner to the overload mode by using an external temperature of the dehumidification-type air cleaner measured by the temperature sensor for measuring an external temperature or the size of a supply current introduced to the electric motor of the compressor 122. Namely, when the input external temperature value is greater than an overload reference value, the controller 140 may determine that the dehumidifying unit 120 is overloaded, and when the size of the supply current is greater than a reference current value, the controller 140 may determine that the dehumidifying unit 120 is overloaded. When the controller 140 determines that the dehumidifying unit is overloaded, the controller 140 may change the operation mode of the dehumidification-type air cleaner to the overload mode. In addition, even when the temperature of the heat exchanger is higher than the pre-set temperature value, the controller 140 may determine the overload and change the dehumidification-type air cleaner to the overload mode.

When the operation mode of the dehumidification-type air cleaner corresponds to the overload mode, the dehumidification-type air cleaner may preferentially perform an operation for resolving the overloaded dehumidifying unit 120. Namely, the controller 140 may increase the rotational speed of the intake fan 130 to the overload driving speed. The overload driving speed is a rotational speed exceeding that for a general dehumidifying operation. As the intake fan 130 is operated at the overload driving speed, the dehumidifying unit 120 may be cooled. When the dehumidifying unit 120, specifically, the compressor 122, is cooled, the overloaded state of the dehumidifying unit 120 may be resolved.

In addition, the controller 140 may be operated in a recommended humidity mode according to a recommended humidity operation command input by the user by using an interface unit (not shown) that may be attached to the outside of the dehumidification-type air cleaner. Namely, when the user inputs the recommended humidity operation command, a recommended humidity operation signal may be input to the controller 140.

When the recommended humidity operation signal is input, the controller 140 may receive an external humidity value measured by the humidity sensor S1. When the external humidity value exceeds a reference humidity value, e.g., 60%, the controller 140 may operate the dehumidifying unit 120 to control vapor in the air such that the external humidity value is reduced to below 60%. When the external humidity value is within a recommended humidity range, e.g., 40% to 60%, the dehumidifying operation may be stopped. Here, the reference humidity value and the recommended humidity range may not be limited to the foregoing value and range and may be variably set.

Compressor start noise reduction controlling will hereinafter be described.

When a dehumidification operation signal is input, first, the controller 140 may increase the rotational speed of the intake fan 130 to a pre-set rotational speed. Thereafter, the dehumidifying unit 120 may be driven only when the rotational speed is higher than the pre-set rotational speed.

In order for the dehumidification-type air cleaner to perform a dehumidification function, both the intake fan 130 and the dehumidifying unit 120 are required to be operated. Here, when the dehumidifying unit 120 initially operates, noise and vibrations may be generated due to the operation of the dehumidifying unit 120, and here, the user may be startled by the abrupt noise and vibrations according to the operation of the dehumidifying unit 120 and may determine that there is a fault in the operation of the dehumidification-type air cleaner.

Meanwhile, in general, noise generated according to the rotation of the intake fan 130 is less audible than noise generated according to the operation of the dehumidifying unit 120, and users may be familiar enough not to be startled by noise generated according to the rotation of the intake fan 130.

Thus, the controller 140 may drive the intake fan 130 before the operation of the dehumidifying unit 120. With noise generated according to the driving of the intake fan 130, the user may recognize that the dehumidification-type air cleaner has started to operate, and thereafter, although the dehumidifying unit 120 operates to generate noise and vibrations, the user may recognize it as a normal operation of the dehumidification-type air cleaner. Also, the noise generated according to the operation of the dehumidifying unit 120 may be buried in noise generated according to the driving of the intake fan 130, so the user may recognize a relatively low level of noise generated according to the operation of the dehumidifying unit 120.

In detail, in order to properly obtain the effect of first driving the intake fan 130, the dehumidifying unit 120 may be operated after the intake fan 130 is operated at a pre-set speed or higher. Namely, since the size of noise generated according to the rotation of the intake fan 130 should sufficiently cover noise generated by the dehumidifying unit 120, the rotational speed of the intake fan 130 may be previously set to generate noise having a magnitude intended by the intake fan 130.

After receiving the dehumidification operation signal, the controller 1400 may operate the intake fan 130, and upon receiving the rotational speed of the intake fan 130 from the intake fan 130, the controller 140 may repeatedly compare the received rotational speed with a pre-set rotational speed. Thereafter, when the rotational speed of the intake fan 130 is measured to be higher than the pre-set rotational speed, the controller 140 may transmit a control signal to the dehumidifying unit 120 to start operations of the dehumidifying unit 120. Alternatively, a time duration taken for the intake fan 130 to reach the pre-set rotational speed is previously set, and when the pre-set time duration has lapsed, the controller 140 may operate the dehumidifying unit 120.

Here, the controller 140 may specifically control the operation of the compressor 122 of the dehumidifying unit 120. As discussed above, the compressor 122 may serve to compress a refrigerant by using an electric motor, so noise and vibrations generated by the dehumidifying unit 120 may result from the electric motor of the compressor 122.

Thus, when the rotational speed of, specifically, the intake fan 130 is higher than the pre-set rotational speed, the controller 140 may drive the compressor 122. Here, when the intake fan 130 is operated at the pre-set rotational speed, noise having a level equal to or greater than that of noise generated when the compressor 122 starts to be operated is generated.

The controller 140 may receive a dehumidification operation signal. When the controller 140 receives the dehumidification operation signal, the controller 140 may control the dehumidification-type air cleaner such that the dehumidifying unit 120 performs the dehumidification function. The dehumidification operation signal may be input by the user through an interface unit (not shown) provided at the outside of the dehumidification-type air cleaner or may be input when the humidity value of the external air is higher than the reference humidity value.

After the compressor 122 is driven, the controller 140 may reset the rotational speed of the intake fan 130 to the dehumidification operational speed. When the compressor 122 is driven, noise and vibrations may be reduced in comparison to the case in which the compressor 122 starts. Thus, when the compressor 122 starts to be driven, the rotational speed of the intake fan 130 is reduced to be rotated at a speed appropriate for the dehumidifying operation, i.e., a dehumidification operational speed.

FIG. 8 is a flow chart illustrating a process of a method of controlling an air current force of the dehumidification-type air cleaner according to an embodiment of the present invention.

With reference to FIG. 8, the method of controlling an air current force of the dehumidification-type air cleaner according to an embodiment of the present invention may include an air purification step (S810), a dehumidification operation signal input step (S820), a purification mode type determination step (S830), a dehumidification step (S840), and a function purification step (S850).

Hereinafter, the method of controlling an air current force of the dehumidification-type air cleaner according to an embodiment of the present invention will be described.

In the air purification step (S810), a rotational speed of the intake fan may be set according to a pre-set purification mode, and contaminants included in external air introduced according to a rotation of the intake fan may be filtered out. The purification mode may include a general purification mode and a functional purification mode. The general purification mode may be a mode in which a rotational speed of the intake fan is set according to an air current force requested by the user and contaminants included in the air introduced by the intake fan are removed by using a filter. The functional purification mode may be a mode in which the intake fan is operated according to each rotational speed thereof previously set according to respective functions to thus perform the respective functions. The functional purification mode may include, for example, a yellow dust mode, a laundry drying mode, a sleep mode, and the like. In the case of the yellow dust mode, concentration yellow dust introduced into an indoor area during yellow dust season and that of various harmful contaminants included in the yellow dust may be high, so the yellow dust mode may be a mode in which the harmful materials introduced into the dehumidification-type air cleaner may be quickly processed. The sleep mode may be a mode in which the dehumidification-type air cleaner is operated such that noise thereof is minimized. In the sleep mode, a rotational speed of the intake fan is set to be minimal.

In the dehumidification operation signal input step (S820), a dehumidification operation signal for operating the dehumidifying unit to remove vapor included in the external air may be received. While the dehumidification-type air cleaner operates in the purification mode, the dehumidification operation signal may be received, and here, the dehumidification operation signal may also include information regarding the rotational speed of the intake fan. In this case, whether to set the rotational speed of the intake fan 130 to a speed previously set in the purification mode or whether to set the rotational speed of the intake fan 130 according to a intake fan rotational speed of the dehumidification operation signal may be in question. Namely, if the rotational speed of the intake fan 130 is adjusted to the speed previously set in the purification mode, the rotational speed of the intake fan 130 is fast enough to drastically degrade the dehumidification effect of the dehumidifying unit 120, and conversely, if the rotational speed of the intake fan 130 is set according to the dehumidification operation signal, the rotational speed of the intake fan 130 is changed, especially in the functional purification mode, potentially resulting in a failure of obtaining an effect intended through the functional purification mode. Here, the dehumidification operation signal may be directly received from the user, or even when the humidity of the external air is higher than the reference humidity value, the dehumidification operation signal may be received.

In the purification mode type determination step (S830), whether or not the purification mode is a general purification mode or the functional purification mode may be determined. As discussed above, the purification mode may be divided into the general purification mode and the functional purification mode, so it may be discriminated to which mode the dehumidification-type air cleaner corresponds currently. Here, when the purification mode is the general purification mode, the dehumidification step (S840) may be performed, and when the purification mode is the functional purification mode, the function purification step (S850) may be performed. The foregoing problem may be solved by differentiating the steps to be performed according to the purification mode.

In the dehumidification step (S840), when the purification mode is the general purification mode, the rotational speed of the intake fan may be reset according to the dehumidification operation signal and the dehumidifying unit may be operated to perform a dehumidifying operation. The general purification mode is a mode in which air purification is performed on air introduced based on an air current force set by the user, and so on, and in this mode, any additional function or effect cannot be expected in the case of the air current force set by the user. Also, the input of the dehumidification operation signal means that a dehumidification operation is required to be performed, so the dehumidification function may be considered to be preferentially performed. Thus, when the dehumidification operation is input while the dehumidification-type air cleaner is being operated, the dehumidification function may be performed by using the dehumidifying unit 120, and the operational speed of the intake fan 130 may be reset to a dehumidification operational speed according to the dehumidification operation signal. In the dehumidification step (S840), the dehumidification-type air cleaner may perform a dehumidification operation and remove vapor from the air. Here, the rotational speed of the intake fan may be reset to a dehumidification operational speed previously set according to the humidity value of the external air.

In the function purification step (S850), when the purification mode is the functional purification mode, the rotational speed of the intake fan may be maintained and the dehumidification operation may not be performed. The functional purification mode may be a mode for executing pre-set functions such as the yellow dust mode, the laundry drying mode, the sleep mode, and the like, and in order to perform the functions, it is essential to maintain the rotational speed of the intake fan at the rotational speed set in the functional purification mode. Thus, in the functional purification mode, the rotational speed of the intake fan set in the functional purification mode may be maintained as it is in spite of the dehumidification operation signal. Also, in relation to the dehumidifying operation, when the dehumidifying operation is performed while the rotational speed of the intake fan set in the functional purification mode is maintained as it is, the dehumidification effect may be drastically degraded and this may damage reliability of the user of the dehumidification-type air cleaner. Thus, when the dehumidification-type air cleaner operates in the functional purification mode, the dehumidification-type air cleaner may not perform a dehumidifying operation in spite of the dehumidification operation signal. Here, the dehumidification-type air cleaner may display the fact that it cannot perform the dehumidifying operation on a display unit that may be provided in a housing of the dehumidification-type air cleaner.

In addition, although not shown, the method for controlling an air current force of the dehumidification-type air cleaner may further include an air purification returning step in which the dehumidification-type air cleaner is returned to the purification mode when the humidity of the external air falls so as to be lower than the reference humidity value, after the dehumidification step (S840). Namely, the user may want to maintain a certain level of humidity together with air purification, and in this case, the dehumidification-type air cleaner may be required to be returned to the purification mode after the dehumidification step (S840). Here, in order to set the rotational speed of the intake fan, an amount of contaminants in the external air may be measured by a dust sensor, based on which a rotational speed of the intake fan may be set. In detail, a purification driving speed of the intake fan corresponding to the amount of dust measured by the dust sensor is set beforehand, based on which the rotational speed of the intake fan may be reset.

Also, in the method for controlling an air current force of the dehumidification-type air cleaner, an external illumination value is measured, and when the measured illumination value is lower than a reference illumination value, the dehumidification-type air cleaner is changed to a sleep mode, stopping the operation of the dehumidifying unit. The external illumination value may be a value measured by the illumination sensor provided outside the dehumidification-type air cleaner. When the external illumination value measured by the illumination sensor is lower than a pre-set value, it may be determined that it is dark and operates the dehumidification-type air cleaner to a sleep mode.

The sleep mode is a mode in which the dehumidification-type air cleaner is operated such that a user s sleep is not interrupted by noise generated by the dehumidification-type air cleaner, and in this mode, the dehumidification-type air cleaner may be operated by minimizing noise generated therefrom. In detail, the largest proportion of noise generated by the dehumidification-type air cleaner may be caused by noise resulting from the rotation of the intake fan and a sound generated as a refrigerant is compressed by the compressor of the dehumidifying unit by using an electric motor. Thus, when the dehumidification-type air cleaner is in the sleep mode, the operation of the compressor of the dehumidifying unit may be stopped and the intake fan may be set to operate at a rotational speed lower than a pre-set sleep mode rotational speed.

Here, however, when the user directly inputs the dehumidification operation signal, although the external illumination value of the illumination sensor is lower than the pre-set value, the dehumidification-type air cleaner may not be operated in the sleep mode. Namely, in this case, the dehumidifying unit may be operated to perform a dehumidification function according to a user intention to remove vapor from the air.

Also, in the method for controlling an air current force of the dehumidification-type air cleaner, when a laundry drying signal is input, the dehumidifying unit is operated and the rotational speed of the intake fan may simultaneously be increased to a laundry drying speed. The laundry drying signal may be input through an interface unit that may be provided on the housing of the dehumidification-type air cleaner. When the laundry drying signal is received, the laundry can be quickly dried by controlling the operation of the dehumidification-type air cleaner.

In detail, a method of simultaneously operating the dehumidifying unit and increasing the rotational speed of the intake fan to the laundry drying speed may be utilized. In general, when an air current speed is excessively fast while a dehumidifying device is performing a dehumidification function, a dehumidification function cannot be properly performed. However, in relation to drying of the laundry, it may be more effective to provide a larger amount of air volume to remove humidity included in the laundry. Thus, the rotational speed of the intake fan may be set to the laundry drying rotational speed higher than the maximum rotational speed used in performing the dehumidification function. Namely, although dehumidification performance according to the performing of dehumidification function of the dehumidifying unit may be degraded, the laundry may be dried quickly by increasing the air volume supplied to the laundry.

For reference, in the above description, it is expressed such that the respective steps are sequentially performed, but these steps may be performed in parallel or the order of the respective steps may be changed to be performed.

FIG. 9 is a flow chart illustrating a process of a method of defrosting the dehumidification-type air cleaner according to an embodiment of the present invention.

With reference to FIG. 9, a defrosting method according to an embodiment of the present invention may include a dehumidifying operation (S910), a defrosting mode changing operation (S920), a defrosting operation (S930), and a dehumidification mode returning steep (S940).

Hereinafter, a method of defrosting the dehumidification-type air cleaner according to an embodiment of the present invention will be described with reference to FIG. 9.

In the dehumidifying operation (S910), a refrigerant is compressed with a compressor, liquefied by a condenser, and evaporated by using an evaporator to thus cool introduced air, whereby the dehumidification-type air cleaner can operate in a dehumidification mode in which humidity in the introduced air is removed. The dehumidifying operation (S910) may be a general dehumidifying method for removing humidity in the air by using a compressor, a condenser, and an evaporator.

In the defrosting mode changing operation (S920), whether or not to change the dehumidification-type air cleaner to a defrosting mode to remove frost formed on the evaporator may be determined. When dehumidification is performed in a low temperature environment, humidity in the air is frozen on the surface of the evaporator, forming frost on the surface of the evaporator. When the surface of the evaporator is frosted, humidity cannot be smoothly removed from the evaporator, so the frost is required to be removed. Here, the dehumidification-type air cleaner may be changed from the dehumidification mode in which humidity is removed in such a manner as that of the dehumidifying operation to a defrosting mode to remove frost.

In the defrosting mode changing operation (S920), when a surface temperature of the evaporator is lower than a defrosting reference temperature, the dehumidification-type air cleaner may be changed to the defrosting mode. In order to effectively remove humidity, preferably, a defrosting operation is performed only when the evaporator is frosted, so it may be important to determine a point in time at which the dehumidification-type air cleaner is to be changed to the defrosting mode. In order to determine a point in time at which the dehumidification-type air cleaner is to be changed to the defrosting mode, a surface temperature of the evaporator may be utilized, and the surface temperature of the evaporator may be measured with a temperature sensor. In detail, a surface temperature of the evaporator is measured by using the temperature sensor, and when the measured surface temperature is lower than the defrosting reference temperature, it may be considered that the evaporator is defrosted. The defrosting reference temperature may be a temperature at which liquefied vapor starts to be frozen in the evaporator. Besides, when the temperature signal is maintained at the defrosting reference temperature for a reference time or more, the dehumidification-type air cleaner may be changed to the defrosting mode, or the dehumidification-type air cleaner may be repeatedly changed to the defrosting mode at pre-set periods to perform a defrosting operation. In addition, in general, whether to change to the defrosting mode may be determined based on the temperature signal, and when the temperature signal is not input or when the input temperature signal is outside of a pre-set range, the dehumidification-type air cleaner may be changed to the defrosting mode at pre-set periods. When the temperature signal is not input or when the input temperature signal is outside of the pre-set range, it may be determined that there is an error in the temperature sensor for generating the temperature signal.

In the defrosting operation (S930), when the dehumidification-type air cleaner is changed to the defrosting mode, power to the compressor may be cut off and a driving speed of the intake fan may be increased to a defrosting driving speed. When it is determined that frost is formed on the surface of the evaporator, the dehumidification-type air cleaner may be changed to the defrosting mode to defrost the evaporator. In the defrosting mode, introduced air may stop being cooled in the evaporator by cutting off power thereto. This is to prevent frost from being additionally formed through cooling of the evaporator. Also, the driving speed of the intake fan may be increased to the defrosting driving speed to allow a large amount of external air to be supplied to the evaporator. The external air may have a temperature higher than that of the evaporator so it may transmit heat to the evaporator. Due to the heat transmitted by the external air, the surface temperature of the evaporator may be increased, and accordingly, frost formed on the surface of the evaporator can be removed.

In the dehumidification mode returning operation (S940), when the evaporator is defrosted in the defrosting mode, the dehumidification-type air cleaner may be returned to the dehumidification mode. Namely, after the frost formed on the evaporator is removed, the dehumidification-type air cleaner is required to be returned to the dehumidification mode in order to remove humidity from the introduced air. In detail, in the defrosting mode returning operation S940, when the surface temperature of the evaporator is increased to be higher than the defrosting reference temperature, power may be supplied to the compressor and the driving speed of the intake fan may be reduced to the dehumidification operational speed. When the surface temperature of the evaporator is higher than the defrosting reference temperature, frost may not exist on the surface of the evaporator, so it may be considered that the frost on the surface of the evaporator have been removed. Thus, when the surface temperature of the evaporator is higher than the defrosting reference temperature, the dehumidification-type air cleaner may be returned to the dehumidification mode. In order to return to the dehumidification mode, power may be supplied to the compressor and the evaporator may cool introduced air to remove vapor therefrom. Also, for the purpose of effective dehumidification, the driving speed of the intake fan may be reduced from the defrosting driving speed to the dehumidification operational speed.

FIG. 10 is a flow chart illustrating a process of a method of drying a heat exchanger of a dehumidification-type air cleaner according to an embodiment of the present invention. FIG. 11 is a flow chart illustrating a process of a method of drying a heat exchanger of a dehumidification-type air cleaner according to another embodiment of the present invention.

A method for drying a heat exchanger (or a heat exchanger drying method) will be described with reference to FIGS. 10 and 11.

With reference to FIG. 10, a heat exchanger drying method according to an embodiment of the present invention may include a dehumidification stopping operation (S1010), a sensor measuring operation (S1020), an operation setting operation (S1030), and an intake fan driving operation (S1040).

In the dehumidification stopping operation (S1010), a dehumidification operation of the dehumidification-type air cleaner may be stopped. Since drying of the heat exchanger should be performed after the dehumidification operation of the dehumidification-type air cleaner is finished, the dehumidification operation of the dehumidification-type air cleaner may first be stopped. The dehumidification operation may be stopped according to user input or may be stopped when a pre-set dehumidification operation time has lapsed. Alternatively, when a level of humidity of external air is less than a reference humidity value, the dehumidification operation may be stopped.

In the sensor measuring operation (S1020), when the dehumidification operation is stopped, an internal temperature and humidity of the dehumidification-type air cleaner may be measured by using the temperature and humidity sensor provided in the dehumidification-type air cleaner. Here, the temperature and humidity sensor may measure temperature and humidity of the heat exchanger. An operation of the intake fan for drying the heat exchanger may be controlled according to the measured temperature and humidity values.

In the operation setting operation (S1030), the operation of the intake fan may be set according to the measured temperature and humidity value. Here, in the operation setting operation (S1030), an operational mode of the intake fan may be set according to the temperature and humidity, and an operational speed and an operation time of the intake fan may be determined according to the respective operational modes. In detail, in the operation setting operation (S1030), first, when a heat exchanger temperature value (T sensor) is greater than a reference temperature value (T reference) and the heat exchanger humidity value (H sensor) is greater than a reference humidity value (H reference), the dehumidification-type air cleaner may be set to a first operational mode (S1031). When a heat exchanger temperature value (T sensor) is lower than the reference temperature value (T reference) and the heat exchanger humidity value (H sensor) is greater than a reference humidity value (H reference), the dehumidification-type air cleaner may be set to a second operational mode (S1032). When a heat exchanger temperature value (T sensor) is lower than the reference temperature value (T reference) and the heat exchanger humidity value (H sensor) is lower than a reference humidity value (H reference), the dehumidification-type air cleaner may be set to a third operational mode (S1033). Namely, the operational mode of the intake fan may be set according to the respective heat exchanger temperature values and humidity values.

In the intake fan driving operation (S1040), the intake fan may be driven according to the pre-set operation of the intake fan. In detail, in the first operational mode, the intake fan may be operated at a first operational speed during a first operational time duration (S1041). Here, when the rotational speed of the intake fan 130 is divided into three levels of speed, high, medium, and low, from fast to slow, the first operational speed may correspond to the medium level speed, and when the operational time duration of the intake fan is divided into three stages, high, medium, and low, from longer to shorter, the first operational time duration may correspond to the high stage.

Next, in the second operational mode, the intake fan may be operated at a second operational speed during a second operational time duration (S1042). Here, the second operational speed may correspond to the low level speed and the second operational time duration may correspond to the medium stage.

Finally, in the third operational mode, the intake fan may be operated at a third operational speed during a third operational time duration (S1042). Here, the third operational speed may correspond to the low level speed and the third operational time duration may correspond to the low stage.

With reference to FIG. 11, a heat exchanger drying method according to another embodiment of the present invention may include a dehumidification stopping operation (S1110), a sensor measuring operation (S1120), an operation setting operation (S1130), and an intake fan driving operation (S1140).

The dehumidification stopping operation (S1110), the sensor measuring operation (S1120), and the intake fan driving operation (S1140) have been described above, so a detailed description thereof will be omitted.

Here, in the operation setting operation (S1130), unlike the operation setting operation of FIG. 7, the operation of the intake fan may only be set with a humidity value of the heat exchanger. Namely, the operational mode of the intake fan may be set by comparing the heat exchanger humidity value (H sensor) with a pre-set minimum humidity value H_min and a pre-set maximum humidity value H_max. In detail, when the heat exchanger humidity value (H sensor) is greater than the pre-set maximum humidity value, the intake fan may set to the first operational mode (S1131), and when the heat exchanger humidity value (H sensor) is smaller than the pre-set maximum humidity value and greater than the pre-set minimum humidity value H_min, the intake fan may be set to the second operational mode (S1132). Finally, when the heat exchanger humidity value (H sensor) is smaller than the pre-set minimum humidity value so the intake fan does not correspond to the first operational mode and the second operational mode, the intake fan may set to the third operational mode.

When the operational mode of the intake fan is set in the operation setting operation (S1130), the intake fan may be driven at a corresponding operational mode during a corresponding operational time duration in the intake fan driving operation (S1140). Namely, when the intake fan corresponds to the first operational mode, the intake fan is operated at the first operational speed during the first operational time duration (S1141). When the intake fan corresponds to the second operational mode, the intake fan is operated at the second operational speed during the second operational time duration (S1142). When the intake fan corresponds to the third operational mode, the intake fan is operated at the third operational speed during the third operational time duration (S1143).

The intake fan driving operation (S1140) is the same as that described above with reference to FIG. 10, so a detailed description thereof will be omitted.

FIG. 12 is a flow chart illustrating a process of a method of controlling an overload of a dehumidification-type air cleaner according to an embodiment of the present invention.

With reference to FIG. 12, a method of controlling an overload of a dehumidification-type air cleaner according to an embodiment of the present invention may include a filtering operation (S1210), a dehumidifying operation (S1220), an overload mode changing operation (S1230), an overload operation (S1240), a dehumidification mode returning operation (S1250), and a recommended humidity operating operation (S1260).

Hereinafter, the method of controlling an overload of a dehumidification-type air cleaner according to an embodiment of the present invention will be described.

In the filtering operation (S1210), with respect to air introduced according to an air flow formed by the intake fan, contaminants included in the air may be filtered out by using a filter unit. The filter unit may be divided into a first filter unit for filtering out contaminants when air is introduced into the dehumidification-type air cleaner and a second filter unit for filtering out contaminants when the introduced air is expelled to the outside of the dehumidification-type air cleaner. The respective filter units may include a plurality of filters. The first filter unit may include a pre-filter, a functional filter, and the like, and the second filter unit may include a HEPA filter, a deodorization filter, and the like.

In the dehumidifying operation (S1220), a refrigerant is compressed with a compressor, liquefied by a condenser, and evaporated by using an evaporator to thus cool introduced air, whereby the dehumidification-type air cleaner can operate in a dehumidification mode in which humidity in the introduced air is removed. When the dehumidification-type air cleaner performs a dehumidifying operation to remove vapor from the air, the dehumidification-type air cleaner may operate in the dehumidification mode using the compressor, the condenser, the evaporator, and the like. However, heat exchange in the evaporator may be significantly affected by an external temperature of the dehumidification-type air cleaner, and when the external temperature is equal to or higher than an overload temperature, heat exchange in the evaporator may not be smoothly performed. In this case, the compressor may be overheated to allow a high level of current to flow therein, and in order to protect the compressor, the operation of the compressor may be stopped. A state in which the compressor is overheated to allow a high level of current to flow therein because heat exchange in the evaporator is not smooth may be known as an overload.

In the overload mode changing operation (S1230), whether or not to change to an overload mode to resolve the overload applied to the compressor may be determined. When the operation of the compressor is stopped due to the overload, the dehumidification-type air cleaner may stop the dehumidifying operation, so in order to prevent this, controlling may be performed. First, in order to determine whether or not the compressor is overloaded, an external temperature of the dehumidification-type air cleaner or the size of a current supplied to the compressor may be measured and the measured values may be compared with reference values. Namely, when the measured external temperature value and the size of the current supplied to the compressor are greater than an overload reference temperature value and a reference current value, it may be determined that the compressor is overloaded. When the compressor is determined to be overloaded, the dehumidification-type air cleaner is controlled to be operated in the overload mode in order to resolve the overload of the compressor.

In the overload operation (S1240), when the dehumidification-type air cleaner is changed to the overload mode, the rotational speed of the intake fan may be increased to an overload driving speed. The intake fan serves to allow external air to be introduced into the dehumidification-type air cleaner and may form an air flow through rotation. The intake fan may perform an operation for an air purification function as well as a dehumidification function, so it may have a rotational speed range larger than that of a general dehumidifier. Thus, the intake fan may operate at the overload driving speed faster than the rotational speed of a general dehumidifier in the overload mode, and the external air supplied by the intake fan may absorb heat from the compressor to thus cool the compressor. As discussed above, when the compressor is cooled, there is no need to stop the operation of the compressor to protect the compressor, so the dehumidifying operation may be continuously performed.

In the dehumidification mode returning operation (S1250), when the overload applied to the compressor is resolved in the overload operation (S1240), the dehumidification-type air cleaner may be returned to the dehumidifying operation. Since the speed of the intake fan was increased to the overload driving speed to cool the compressor in the overload operation (S1240), dehumidification performance of the dehumidification-type air cleaner may be lessened in comparison to the general dehumidifying operation. Thus, when the external temperature value falls to below the overload reference temperature or when the current supplied to the compressor is lowered to below the reference current value, the dehumidification-type air cleaner may be returned to the dehumidification mode from the overload mode.

In the recommended humidity operating operation (S1260), when a recommended humidity operation signal is input, external humidity is measured. When the measured humidity exceeds a reference humidity value, e.g., 60%, the dehumidifying operation (S1220) may be performed. The dehumidification-type air cleaner may operate in the recommended humidity mode, and in this case, the user may perform inputting by using an interface unit that may be attached to the outside of the dehumidification-type air cleaner. In the recommended humidity mode, an external humidity value measured by the humidity sensor may be received, and when the external humidity value exceeds 60%, the dehumidifying operation (S1220) may be performed. Thereafter, when the external humidity value is within a recommended humidity range, e.g., from 40% to 60%, the operation in the dehumidifying operation (S1220) may be stopped.

For reference, in the above description, the respective operations are described as being sequentially performed, but these operations may be performed in parallel or the order of the operations may be changed in the actual performing of the operations.

With reference to FIG. 13, a method of dehumidifying a dehumidification-type air cleaner according to an embodiment of the present invention may include a dehumidification operation signal input operation (S1310), an intake fan operating operation (S1320), a rotational speed checking operation (S1330), and a dehumidifying unit driving operation (S1340).

Hereinafter, the method of dehumidifying a dehumidification-type air cleaner according to an embodiment of the present invention will be described with reference to FIG. 13.

In the dehumidification operation signal input operation (S1310), the dehumidifying unit of the dehumidification-type air cleaner may receive a dehumidification operation signal for controlling the dehumidifying unit to perform a dehumidifying operation to remove vapor from the air. The dehumidification operation signal may be a signal for operating the dehumidifying unit of the dehumidification-type air cleaner to remove vapor from the air introduced into the dehumidification-type air cleaner. The dehumidification operation signal may be received from the user through an interface unit (not shown) positioned outside the dehumidification-type air cleaner. The dehumidification-type air cleaner may separately perform a dehumidification function of removing vapor from the air and an air purification function of removing contaminants in the air or may perform the both functions simultaneously. The dehumidification operation signal may only be input when the dehumidification function is performed or when both the dehumidification function and the air purification function are simultaneously performed.

In the intake fan operating operation (S1320), when the dehumidification operation signal is input, the intake fan may be operated to allow external air to be introduced into the dehumidification-type air cleaner. When the dehumidification operation signal is input, first, the intake fan may be operated, and here, noise may be generated due to the operation of the intake fan. In order to perform the dehumidifying operation, the intake fan should be operated together with the dehumidifying unit provided in the dehumidification-type air cleaner, and here, only the intake fan may be operated before operating the dehumidifying unit.

In the rotational speed checking unit (S1330), whether or not the rotational speed of the intake fan is equal to or faster than a pre-set rotational speed may be determined. After the intake fan is operated, the rotational speed of the intake fan may be determined. As mentioned above, rotating the intake fan first is to generate noise first by the operation of the intake fan and then operating the dehumidifying unit. Thus, the rotational speed of the intake fan may be gradually increased until when it reaches the pre-set rotational speed. In general, the amount of generated noise is increased as the rotational speed of the intake fan is increased, so the rotational speed of the intake fan may be checked to determine whether or not noise generated by the intake fan is increased to reach a target level of noise. Here, the size of the target noise may be equal to or greater than noise generated when the dehumidifying unit is operated.

In the dehumidifying unit driving operation (S1340), when the rotational speed of the intake fan is equal to or faster than the pre-set rotational speed, the dehumidifying unit of the dehumidification-type air cleaner may be driven. Namely, when the rotational speed of the intake fan is equal to or faster than the pre-set rotational speed, the amount of noise generated by the intake fan may be equal to or greater than the target noise. Thus, at this point of time, although the dehumidifying unit of the dehumidification-type air cleaner is driven, the user may not be startled by noise and vibrations according to the driving of the dehumidifying unit and may not mistake it as malfunctioning of the dehumidification-type air cleaner. Here, driving of the dehumidifying may specifically mean that the compressor, a constituent element of the dehumidifying unit, is driven. The compressor compresses a refrigerant, and since the compressor compresses a refrigerant by using an electric motor, a large amount of noise and vibrations may be generated when the compressor is operated. Thus, when the intake fan operates at a rotational speed equal to or faster than a pre-set rotational speed, specifically, the compressor of the dehumidifying unit may start to be driven.

Although not shown, after the dehumidifying unit is driven, a dehumidification operational speed resetting operation of resetting the rotational speed of the intake fan to a dehumidification operational speed may be additionally performed. After the dehumidifying unit, specifically, the compressor, is driven, noise and vibrations generated by the compressor may be reduced. Thus, when the compressor starts to be driven, the rotational speed of the intake fan may be reduced and the intake fan may be rotated at a speed appropriate for the dehumidifying operation, namely, at a dehumidification operational speed.

While the present invention has been shown and described in connection with the embodiments, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

A method for controlling an air current force of a dehumidification-type air cleaner, the method comprising:

an air purification operation of setting a rotational speed of a intake fan according to a pre-set purification mode and filtering out contaminants from external air introduced according to a rotation of the intake fan;

a dehumidification operation signal input operation of receiving a dehumidification operation signal for operating a dehumidifying unit to remove vapor included in the external air;

a dehumidifying operation of resetting the rotational speed of the intake fan according to the dehumidification operation signal when the purification mode is a general purification mode, and operating the dehumidifying unit to perform a dehumidification operation; and

a function purification operation of maintaining the rotational speed of the intake fan when the purification mode is a function purification mode and not performing the dehumidifying operation.
The method of claim 1, wherein, in the dehumidification operation signal input operation, when humidity of the external air is equal to or greater than a reference humidity value, the dehumidification operation signal is received.
The method of claim 2, wherein, in the dehumidifying operation, the rotational speed of the intake fan is reset to a pre-set dehumidification operational speed according to the humidity value of the external air.
The method of claim 2, further comprising an air purification returning operation of resetting the rotational speed of the intake fan to a pre-set purification driving speed according to the amount of contaminants in the external air measured by a dust sensor, when the humidity of the external air falls to below the reference humidity value.
The method of claim 1, further comprising a sleep mode changing operation of measuring an external illumination value, stopping the operation of the dehumidifying unit, entering a sleep mode, and resetting the rotational speed of the intake fan to a noiseless speed, when the measured illumination value is lower than a reference illumination value.
The method of claim 1, further comprising a laundry drying operation of increasing the rotational speed of the intake fan to a laundry drying operational speed, while operating the dehumidifying unit, when a laundry drying signal is input.
A dehumidification-type air cleaner comprising:

a filter unit filtering out contaminants included in the air introduced thereinto;

a dehumidifying unit removing vapor included in the introduced air;

an intake fan rotated by a motor to allow external air to be introduced into the dehumidification-type air cleaner; and

a controller operating the dehumidification-type air cleaner in a purification mode in which the contaminants are filtered out by adjusting a rotational speed of the intake fan without driving the dehumidifying unit, and determining whether to operate the dehumidifying unit and resetting the rotational speed of the intake fan according to a type of the purification mode, when a dehumidification operation signal for operating the dehumidifying unit is input.
The dehumidification-type air cleaner of claim 7, wherein when humidity of the external air is equal to or greater than a reference humidity value, the controller receives the dehumidification operation signal.
The dehumidification-type air cleaner of claim 7, wherein when the purification mode is a general purification mode, the controller sets the operation of the dehumidifying unit and the rotational speed of the intake fan according to the dehumidification operation signal, and when the purification mode is a function purification mode, the controller maintains the operation according to the function purification mode.
The dehumidification-type air cleaner of claim 9, wherein the controller receives an external illumination value, and when the received illumination value is lower than a pre-set value, the controller stops the operation of the dehumidifying unit and operates the dehumidification-type air cleaner in a sleep mode.
The dehumidification-type air cleaner of claim 9, wherein when a laundry drying signal is input, the controller operates the dehumidifying unit and simultaneously increases the rotational speed of the intake fan to a laundry drying speed.
A dehumidification-type air cleaner comprising:

a filter unit filtering out contaminants included in the air introduced thereinto;

a dehumidifying unit removing vapor included in the introduced air;

an intake fan rotated by a motor to allow external air to be introduced into the dehumidification-type air cleaner;

a sensor unit including a humidity sensor measuring a humidity value of the air and a dust sensor measuring an amount of dust in the air; and

a controller operating the dehumidifying unit when the measured humidity value is greater than a reference humidity, setting a rotational speed of the intake fan according to the measured humidity value, stopping the operation of the dehumidifying unit when the measured humidity value is lower than the reference humidity, and setting the rotational speed of the intake fan according to the measured amount of dust.
The dehumidification-type air cleaner of claim 12, wherein the sensor unit further comprises an illumination sensor measuring an external illumination,

wherein when the measured illumination value is lower than a reference illumination, the controller stops the operation of the dehumidifying unit.
The dehumidification-type air cleaner of claim 13, wherein when the measured illumination value is lower than a reference illumination, the controller resets the rotational speed of the intake fan to a noiseless speed.
The dehumidification-type air cleaner of claim 12, wherein a rotational speed range of the intake fan controlled according to the measured humidity value is different from a rotational speed range of the intake fan controlled according to the measured amount of dust.
The dehumidification-type air cleaner of claim 15, wherein the rotational speed range of the intake fan controlled according to the measured humidity value is included in the rotational speed range of the intake fan controlled according to the measured amount of dust.
The dehumidification-type air cleaner of claim 12, wherein when the surface temperature of the dehumidifying unit is lower than a defrosting reference temperature, the controller changes the dehumidification-type air cleaner to a defrosting mode, and in the defrosting mode the controller stops the operation of the dehumidifying unit and the rotational speed of the intake fan set to a defrosting driving speed.
The dehumidification-type air cleaner of claim 17, wherein when the measured surface temperature of the dehumidifying unit is outside of a pre-set range, the controller repeatedly changes the dehumidification-type air cleaner to the defrosting mode at pre-set periods.
The dehumidification-type air cleaner of claim 12, wherein when a control signal for stopping the operation of the dehumidifying unit is input, the controller changes the dehumidification-type air cleaner to a heat exchanger drying mode, and in the heat exchanger drying mode, the controller sets an operational speed and an operational time duration of the intake fan according to the temperature and humidity of the dehumidifying unit.
The dehumidification-type air cleaner of claim 19, wherein when the temperature of the dehumidifying unit is greater than a reference temperature value and the humidity of the dehumidifying unit is greater than the reference humidity value, the controller sets the intake fan to operate at a first operational speed during a first operational time duration,

when the temperature of the dehumidifying unit is lower than a reference temperature value and the humidity of the dehumidifying unit is greater than the reference humidity value, the controller sets the intake fan to operate at a second operational speed during a second operational time duration, and

when the temperature of the dehumidifying unit is lower than a reference temperature value and the humidity of the dehumidifying unit is smaller than the reference humidity value, the controller sets the intake fan to operate at a third operational speed during a third operational time duration.
The dehumidification-type air cleaner of claim 12, wherein when a temperature value of the introduced air is equal to or greater than an overload reference temperature or when the size of a supply current supplied to the dehumidifying unit is equal to or greater than a reference current value, the controller changes the dehumidification-type air cleaner to an overload mode, and in the overload mode, the controller sets the rotational speed of the intake fan to an overload driving speed.
The dehumidification-type air cleaner of claim 12, wherein when a dehumidification operation signal for operating the dehumidifying unit is input, the controller increases the rotational speed of the intake fan to a pre-set rotational speed, and when the rotational speed of the intake fan reaches the pre-set rotational speed, the controller operates the dehumidifying unit.
A method for controlling a dehumidification-type air cleaner including a filter unit filtering out contaminants included in the air introduced thereinto, a dehumidifying unit removing vapor included in the introduced air, and a controller controlling a rotational speed of an intake fan and an operation of the dehumidifying unit, the method comprising:

measuring a humidity value and an amount of dust of introduced air by using a humidity sensor and a dust sensor;

operating the dehumidifying unit and setting a rotational speed of the intake fan according to the measured humidity value, when the measured humidity value is equal to or greater than a reference humidity; and

stopping the operation of the dehumidifying unit and setting a rotational speed of the intake fan according to the measured amount of dust, when the measured humidity value is smaller than a reference humidity.
The method of claim 23, further comprising measuring an external illumination by using an illumination sensor, and stopping the operation of the dehumidifying unit when the measured illumination value is lower than a reference illumination.
The method of claim 24, wherein when the measured illumination value is lower than the reference illumination, the rotational speed of the intake fan is reset to a noiseless speed.
The method of claim 23, wherein a rotational speed range of the intake fan controlled according to the measured humidity value is different from a rotational speed range of the intake fan controlled according to the measured amount of dust.
The method of claim 26, wherein the rotational speed range of the intake fan controlled according to the measured humidity value is included in the rotational speed range of the intake fan controlled according to the measured amount of dust.