IES66502B2 - A ventilator unit - Google Patents

Abstract

A ventilator unit 1 comprising a generally rectangular casing with a base plate 2 supporting four upstanding walls namely a front wall 3, a back wall 4 and a pair of end walls 5, 6 across which is mounted a cover plate 8. A duct region 12 of the casing has a cranked deflector plate 25 defining in combination with the duct region 12 an enclosed elongate airstream passageway 26 between the fan 22 and the air outlet 16. The deflector plate 25 terminates in a free end, a short distance away from the end wall 6 defining a bend 27 in the passageway 26 to change the direction of the airstream in the duct region 2 through 180° to reduce noise during operation. A generally U shaped baffle 29 is mounted in the bend 27 to divide the airstream into two separate airstreams with different airstream velocities to further reduce operating noise.

Description

A ventilator unit” Introduction The present invention relates to a room ventilator unit, A variety of room ventilator units are known. For example it is known to provide an extractor fan to remove stale air from a room. However, such fans do not provide any filtration for replacement air. It is also known to provide ventilator units known as positive flow dynamic systems which deliver air into a room and filter incoming air. However, such units tend to generate a considerable amount of noise in operation.

There is therefore a need for a room ventilator unit which will overcome at least some of these problems.

Statements of Invention Accordingly there is provided ventilator unit comprising:- a plenumatic room an external air inlet; an internal air outlet; an enclosed duct connecting the air inlet and the air outlet; a fan and an associated fan controller, the fan controller controlling an airstream in the duct between the air inlet and the air outlet; and noise attenuation means downstream of the air inlet for reducing noise below 50dB in the room.

A plenumatic room ventilator formed in this way provides a room with a controlled supply of fresh filtered air at minimum cost. s Γι ι ; ! z v-*’ a—’ -K-* ¢,:..

In one arrangement the noise attenuation means is provided by a deflector plate in the duct region defining an elongate airstream passageway having at least one bend therein to change the direction of the airstream through at least 80° within the duct region.

Thus, the noise of the unit is further reduced without the need for expensive sound proofing materials.

In another a arrangement the passageway is formed to change the direction of the airstream through at least 170° within the duct region.

Preferably the passageway is formed to change the direction of the airstream through at least 260° within the duct region. In this way the natural flow dynamics of the airstream passing through the unit are used to reduce unit noise.

Preferably the plenumatic room ventilator unit has a baffle mounted in the duct to divide the airstream into two separate airstreams with different airstream velocities such that having passed the baffle the two separate airstreams mix together. This significantly reduces the noise of the unit as the risk of airstream whistle is avoided.

Ideally the baffle is mounted in a bend. In this way optimum use of the noise reducing elements of both baffle and bend is obtained.

Preferably, the fan is mounted on a plurality of shock absorbers for reducing noise output from the fan.

Preferably the fan controller incorporates an ambient oxygen level sensor mounted in the room. This allows an operator to pre-set a desired amount of oxygen in the room. The controller may then accurately monitor air condition to automatically switch on or off the fan as necessary to maintain the desired oxygen level to overcoming pollutants such as cigarette smoke which reduce oxygen content. A unit of this type may also include a remote control receiver device to facilitate adjustment.

Preferably the fan controller maintains air pressure in the room at greater than atmospheric pressure.

Preferably the fan controller maintains air pressure in the room at greater than fifteen psi and ideally the air pressure is between sixteen and seventeen psi. This pressure guarantees that air is continuously replaced as air lost by natural seepage for example under doors is quickly replaced by filtered air ensuring a pleasant environment for persons in the room is maintained.

In one embodiment the unit includes an air filter unit downstream of the air inlet, thus, the unit may be configured for a particular requirements such as a pollen filter for hay-fever suffers or an activated charcoal filter for removing smells. Additionally a diffuser filter may be included to further reduce unit noise.

Preferably, the air filter unit is upstream of the fan to allow the fan to draw air through the filter.

Ideally, the air filter unit is demountable, thus the filter unit may be easily removed from the unit to allow replacement of filters.

In a preferred embodiment the internal air outlet has a deflector plate to control the flow of airstream within the room. Preferably air directing means is a plate downstream of the air outlet mounted within the room. This guarantees that air is directed away from persons in the room preventing draughts and also allows the unit to be hidden away from view.

According to one aspect of the invention there is provided a plenumatic ventilator unit comprising:a unit casing, the casing having - 4 a base plate on which is mounted a plurality of upstanding walls namely, a front wall, a back wall and a pair of opposed walls, and a cover plate; spaced apart end an external air inlet in the back wall; an internal air outlet in the front wall; and a divider plate mounted within the casing for dividing the casing into a control region and a duct containing region, the control region having a fan and an associated fan controller, the fan controller controlling the speed of the airstream between the air inlet and the air outlet; a deflector plate defining an elongate airstream passageway in the duct region having at least one bend therein to change the direction of the airstream through at least 80° within the duct region.

Thus the unit may be easily varied in size and may easily be accommodated in a solid or cavity wall or may be mounted in a window sill. The unit may be easily retrofitted to any site and this provides ease of access for maintenance purposes.

Ideally the unit has a baffle mounted in the duct region to divide the airstream into two separate airstreams with different airstream velocities.

Ideally the deflector plate is mounted on the divider plate, extends across portion of the air outlet and terminates adjacent to but spaced apart from one end wall.

Preferably the control region has an air filter unit upstream of the fan.

In a preferred embodiment the casing is mounted in a window sill.

Preferably the external air inlet has a louvred grille for preventing the ingress of water.

Detailed Description The invention will be more clearly understood from the following description of a number of embodiments thereof, given by way of example only with reference to the accompanying drawings in which:Fig. 1 is a perspective view of a room ventilator unit according to the invention? Fig. 2 is a plan view of the room ventilator unit of Fig. 1 with a cover plate removed? Fig. 3 is a front view of the room ventilator unit of Figs. 1 and 2 mounted in a window sill? Fig. 4 is a sectional view of the room ventilator of Figs. 1 and 2 mounted in a wall with internal components of the unit omitted for clarity? Fig. 5 is a plan view with the cover plate removed of another room ventilator unit according to the invention? and Figs. 6 to 13 are schematic views of alternative room ventilator units of the invention.

Referring to the drawings and initially to Figs. 1 and 2, there is illustrated a room ventilator unit indicated generally by the reference numeral 1. The ventilator unit 1 comprises a generally rectangular casing having a base plate 2 supporting four upstanding walls namely a front wall 3, a back wall 4 and a pair of end walls 5,6 across which is mounted a cover plate 8.

A divider plate 10 mounted on the base plate 3 divides the casing into a control region 11 and a duct region 12. - 6 A hole in the back wall 4 provides an external air inlet 15 to allow an airstream into the control region 11 and a similar hole in the front wall 3 provides an internal air outlet 16 for the duct region 12.

The control region 11 has a mixing box 20 downstream of the air inlet 15, a filter unit 21 and a fan 22 delivering through the plate 10. The fan 22 has an associated fan controller 23 for controlling the speed of airstream flowing between the air inlet 15 and the duct region 12.

The duct region 12 has a cranked deflector plate 25 defining in combination with the duct region 12 an enclosed elongate airstream passageway 26 between the fan 22 and the air outlet 16. The deflector plate 25 is mounted on the divider plate 10 and extends into the duct region 12 intermediate the front wall 3 and the back wall 4. The deflector plate 25 terminates in a free end, a short distance away from the end wall 6 defining a bend 27 in the passageway 26 to change the direction of the airstream in the duct region 12 through 180°. A generally U shaped baffle 29 is mounted in bend 27 around the free end of the deflector plate 25 to divide the airstream into two separate airstreams with different airstream velocities.

In use, an ambient oxygen level sensor (not shown) mounted in a room for which the unit 1 is installed, senses that the pressure is below a preset value, typically 16.5 psi or that there is insufficient available oxygen and switches on the fan 22.

Air is drawn into the control region 11 through the air inlet 15 and into the mixing box 20. The airstream is then drawn through the filter unit 31 and delivered to the duct region 12 by the fan 32.

The airstream then encounters the deflector plate 25 and is directed along the passageway 26 and towards the bend 27. When the airstream reaches the baffle 27 it is divided into two separate airstreams having different airstream velocities. The two separate airstreams turn changing the direction of - 7 the bend 27 independently, both airstreams through 180°.

When the two airstreams have passed the baffle 27 they re-mix and continue along the passageway 26, through the internal air outlet 16 and into the room (not shown).

In this way the required reduction in noise levels from the unit is achieved without the use of expensive materials but by routing at least portion of the airstream through 360°. This is achieved by a 90° turn in the mixing box 20, a subsequent change in airstream direction of 180° in the bend 27 and a further 90° turn at the air outlet 16.

Referring now to Figs. 3 and 4, the room ventilator unit 1 is shown mounted in a window sill 29 and in a wall 31. Parts similar to those described with reference to Figs. 1 and 2 are identified by the same reference numerals. The wall mounted unit of Fig. 4 has a deflector plate 32 to control the flow of the airstream within the room. The airstream is delivered from the internal air outlet 16 to the top of the room by striking against the deflector plate 32 and being directed upwards. The plate 32 may be optionally be fitted with a picture thereby hiding air outlet 16 from view.

Referring now to Fig. 5 there is provided an alternative plenumatic room ventilator unit indicated generally by the reference numeral 40. The unit 40 shows has a centrifugal fan 61 and an elongate internal air outlet 41. The deflector plate 25 has a triangular baffle 42 mounted at the free end thereof for changing the air flow velocity. In this case the bend 27 has a rounded deflector plate 43 adjacent the end wall 6.

Referring to Figs. 6 to 13, it will be apparent how the various types of deflector plates and baffles may be arranged to provide different air stream flows. for example, Fig. 6 has a number of deflector plates extending from the divider plate and the end wall part - 8 way into the duct area defining a sinuous air passageway for the airstream.

Many combinations of this feature may be used.

It will be noted that while the embodiment described above shows the deflector plate extending from the separator wall towards the end wall it could equally be mounted on the front wall and extend towards the back wall.

It will be appreciated that by positioning the air outlet 15 close to but not in contact with the deflector plate 25 mounted on the divider plate, an air cushion is formed to direct the airstream outwards, further reducing the noise of the unit.

It will be noted that the use of a deflector plate downstream of the internal air outlet allows the outlet to be hidden from view and prevents persons in the room from feeling that the room is draughty, enhancing comfort.

It will be also be noted that any of the walls or plates may be hingedly mounted to the casing to allow easy access to the unit for maintenance or replacement of the filter unit.

It will further be noted that the filter unit may include a wide variety of interchangeable filter types so that the unit may be used in a number of applications. Additionally, filters to reduce pollen content of the air may be included to aid Asthma sufferers or damp sites may have filters included to reduce humidity.

The unit may be formed to accommodate a variety of fans to enable the unit to be adapted for use in a variety of different size rooms with different air throughput requirements and may incorporate a separate fused power supply unit within the control region. The unit may also include one or more air restrictors to slow or - 9 ~ focus the airstream during delivery through the unit either upstream or downstream of the bend.

It will be appreciated that the mixer box may also include an additional air intake, controlled by the fan controller, for receiving air from a scavenger unit mounted in the room and that the unit may optionally include an air heater or cooler. In this wav heated or cooled air from the room may be combined with fresh air to reduce heating or cooling requirements.

The invention is not limited to the embodiments hereinbefore described, which may be varied in both construction and detail.

The unit described is particularly suitable for use in commercial premises where the air has a high smoke content from cigarettes and cigars. By constantly replacing the air, risks associated with passive smoking are effectively eliminated.

Claims (5)

Claims

1. A plenumatic room ventilator unit comprising:an external air inlet; an internal air outlet; an enclosed duct connecting the air inlet and the air outlet; a fan and an associated fan controller, the fan controller controlling an airstream in the duct between the air inlet and the air outlet; and noise attenuation means downstream of the air inlet for reducing noise below 50dB in the room.

2. A plenumatic room ventilator unit as claimed in claim 1 wherein the noise attenuation means is provided by a deflector plate in the duct region defining an elongate airstream passageway having at least one bend therein to change the direction of the airstream through greater than 80° within the duct region.

3. A plenumatic room ventilator unit as claimed in claim 1 or claim 2 having a baffle mounted in a bend of the duct to divide the airstream into two separate airstreams with different airstream velocities such that having passed the baffle the two separate airstreams mix together.

4. A plenumatic room ventilator unit as claimed in any preceding claim wherein the fan controller incorporates an ambient oxygen level sensor mounted in the room for maintaining air pressure in the room at greater than atmospheric pressure and the internal air outlet has a deflector plate downstream of the air outlet mounted within the room to control the flow of airstream within the room. 11

5. A plenumatic room ventilator unit comprising:a unit casing mounted adjacent a window sill, the casing having a base plate on which is mounted a plurality of upstanding walls namely, a front wall, a back wall and a pair of opposed spaced apart end walls, and a cover plate; an external air inlet in the back wall; an internal air outlet in the front wall; and an enclosed duct connecting the air inlet and the air outlet; a divider plate mounted within the casing for dividing the casing into a control region and a duct containing region, the control region having a fan and an associated fan controller, the fan controller controlling the speed of the airstream between the air inlet and the air outlet; a deflector plate defining an elongate airstream passageway in the duct region having at least one bend therein to change the direction of the airstream through at least 80° within the duct region, the deflector plate being mounted on the divider plate, extending across portion of the air outlet and terminating adjacent to but spaced apart from one end wall; a baffle mounted in the duct region to divide the airstream into two separate airstreams with different airstream velocities; and a demountable air filter unit upstream of the fan.