GB2091452A

GB2091452A - Automatic control of temperature

Info

Publication number: GB2091452A
Application number: GB8101241A
Authority: GB
Original assignee: RAPAWAY Ltd
Current assignee: RAPAWAY Ltd
Priority date: 1981-01-15
Filing date: 1981-01-15
Publication date: 1982-07-28

Abstract

A building environment is controlled by sensing the wind speed and/or direction outside the building, with wind sensing means (15), feeding a signal from said wind sensing means (15) to a control device (9) sensing the temperatures inside and outside the building by temperature sensing means (18, 17) feeding signals from the temperature sensing means (18, 17) to the control device (9), the control device utilising the signal from the wind and temperature sensors (15, 18, 17) to calculate an optimum "on" time to start heating the building (10) before a first set time so that the building environment is heated to a first predetermined temperature at the first set time, and/or an optimum "off" time to stop heating the building (10) before a second set time so that the temperature of the building environment does not fall below a second lower predetermined temperature, by the second set time. <IMAGE>

Description

SPECIFICATION Controlling Building Environments This invention relates to the control of building environments.

It is established practice to heat a building environment when the building is occupied, and to stop heating the building shortly before it is to become unoccupied.

Similarly, it is known to start heating the building environment shortly before the building is to be occupied to allow the building environment to be heated to a desired temperature by the time the building is to be occupied.

Obviously it is undesirable to stop heating too soon before the building becomes unoccupied, or the environment will cool below an acceptable level. Similarly it is desirable to heat the building for an adequate period before it is to be occupied, to ensure that the building environment is adequately heated, but not to start heating too soon and thereby waste heat.

Presently, it is known to control a building environment by continually sensing the internal and outside temperatures of a building when the building is being heated i.e. when occupied, with temperature sensors located inside and outside the building respectively, and to feed signals from the sensors to a control device which calculates the optimum time to stop heating before the building becomes unoccupied, depending upon a selected first temperature below which it is not desired for the building environment to fall after heating is stopped and a selected second temperature at which it is desired to maintain the building environment when occupied and to continually sense the internal and outside temperatures of the building when it is not being heated i.e. when it is unoccupied with said temperature sensors and to feed signals from the sensors to the control device which calculates the optimum time at which to start heating the building environment before the building becomes occupied, to ensure that the building is adequately heated when it is to be occupied.

The time at which the building is to become occupied, and the time at which the building is to become unoccupied are set on the control device appropriately, with the selected first and second temperatures.

It is also known to take account of the building constants e.g. the size of the building and the materials from which the building is made, when calculating the optimum on and off times. These constants are used empirically.

However it has been found that the speed and direction of the wind has a significant effect on the rate at which a building loses heat and thus on the optimum on and off times calculated as described above.

It is therefore an object of the present invention to provide a new or improved method of controlling a building environment.

According to one aspect of the invention, we provide a method of controlling a building environment including the steps of sensing the wind speed and/or direction outside the building, with wind sensing means, feeding a signal from said wind sensing means to a control device sensing the temperatures inside and outside the building by temperature sensing means feeding signals from the temperature sensing means to the control device, the control device utilising the signal from the wind temperature sensors to calculate an optimum "on" time to start heating the building before a first set time so that the building environment is heated to a first predetermined temperature at the first set time, and/or an optimum "off" time to stop heating a building before a second set time so that the temperature of the building environment does not fall below a second lower predetermined temperature, by the second set time.

For example, a building such as a factory may be occupied from 8 a.m. to 6 p.m., during which period it is decided to maintain the building environment at 650F. (1 8.30C.) and for the building environment temperature not to fall below 600F. (1 5.50C.).

The time at which the building becomes occupied i.e. 8 a.m. and the time at which the building becomes unoccupied i.e. 6 p.m. are set on a control device which calculates, with regard to the windspeed and/or direction and the temperatures inside and outside the building that the building environment needs to be heated from say 7 a.m. for the building environment temperature to reach 600F. by 8 a.m., and that the heating can be stopped from 4.45 p.m. so that the building environment cools to 600F by 6 p.m.

The wind speed and/or direction and the temperatures externally and inside the building may each be sensed continuously, or if desired, the wind speed and/or direction and/or the temperature may be sensed at regular periods.

For example, the temperatures inside and outside the building may be sensed at minute intervals but the wind speed and/or direction sensed continuously.

In a preferred arrangement, both the wind speed and the wind direction are sensed. Further preferably, the constants of the building are utilised by the control device to calculate the optimum on and off times.

According to a second aspect of the invention we provide a building having means to sense the wind speed and/or direction outside the building, means to feed a signal from said wind sensing means to a control device, means to sense the temperature inside and outside the building, means to feed signals from said temperature sensing means to the control device, the control device being adapted to utilise the signals from said wind and temperature sensing means to calculate an optimum "on" time to start heating the building before a first set time so that the building environment is heated to a first predetermined temperature at the first set time, and/or an optimum "off" time to stop heating a building before a second set time so that the temperature of the building environment does not fall below a second lower predetermined temperature, by the second set time.

In one arrangement, where the necessary building constants are known, these may be programmed into the control device. However where they are not known, and in particular where they are difficult to measure, the control device may incorporate a self learning device which determines the constants depending on the performance of of the building environment to the calculated heating on and off times.

Control devices are known which take general account of when the building was last inhabited, e.g. on Monday mornings in factories more heat is required to heat the building environment to the first selected temperature than on mornings when the building has been heated the day before.

In the present invention the optimum on time may be calculated depending on the precise period of time which elapses from the the second set time or the calculated optimum off time. This is advantageous when calculating the optimum on time and the first set time is only shortly after the second set time, for example between shifts in a factory.

According to a third aspect of the invention we provide a control device for use in a building according to the second aspect of the invention.

According to a fourth aspect of the invention, we provide a building, the environment of which is controlled by a method according to the first aspect of the invention.

The invention will now be described with reference to the accompanying drawings which is a diagrammatic view of a building, the environment of which is controlled according to the invention.

Referring to the drawings, there is shown a building 10 such as a factory having a heating system 20 which may be switched on or off depending on, for example, whether the building is occupied or not.

The heating system 20 is controlled by a control device 9 which has four inputs 11, 12, 13 and 14 and which can be set by means of two timers, 1 and 2, and signals derived from the inputs 11-14, to ensure that the environment of the building 10 is maintained above a first predetermined temperature set on the control device 9, between the times set on the timers 1 and 2.

Further, the control device ensures that the heating system 20 is switched on at an optimum time so that the building is adequately heated to at least a second predetermined temperature, set on the device 9, by the time set on timer 1, and that the heating system 20 is switched off at an optimum time before the time set on timer 2, so that the building environment does not fall below the second predetermined temperature by the time set on timer 2, thereby ensuring that heat is not unnecessarily wasted.

When the control device 9 calculates these optimum on and off times the signals derived at the inputs 11-14 are also taken into account.

The inputs 11 and 12 are connected to a wind direction and speed sensor 1 5 such as an anenometer which has a transducer 1 6 to provide signals to inputs 11 and 12 which contain information as to the wind speed and direction.

The transducer 1 6 is adapted to provide signals to the control device 9 continuously, and the control device calculates the mean wind speed and direction over a set period.

The inputs 13 and 14 are each connected to a temperature sensor 1 7 or 1 8 respectively, the sensor 17 being located outside the building and therefore sensing the external temperature of the building, and sensor 1 8 being located inside the building and thereby sensing the temperature inside the building 10.

The sensors 1 7 and 18 are arranged to sense the respective temperatures and provide signals to the control device 9 at regular intervals of one minute.

It will be appreciated that heat within the building will escape from the building 10 via the ceilings and roof, such as illustrated by arrow A, and by the walls, windows and doors, as illustrated by arrow B.

The rate of loss of heat will depend upon at least the materials from which the building is made (and the degree to which the building is insulated) and the size of the building. Thus the rate of heat loss will change if for example the degree of ventilation of the building is increased or decreased if a door or window is opened.

The control device 9 is provided with a self learning device and, as the control device 9 continuously senses the external and inside temperatures of the building, the performance of the building, and hence the building constants can be calculated.

As the control device 9 has a self learning device, if the building constants and therefore the rate of heat loss of the building changes, the control device can adjust the optimum on and off times as well as the output of the heating system 20.

Further, the heating system 20 can be adjusted appropriately by the control device 9 to provide the correct amount of heating to maintain the building environment above the first predetermined temperature when the heating system is on.

In another control device, (not shown) where the building constants are known and where it is not desired to take account of any changes in the building constants, the building constants may be programmed into the control device appropriately.

Although the control system shown has four inputs, 11-14, and two timers 1, 2 which can accommodate one on off period per day it will be appreciated that if desired, the control device 9 may have a timer on which it is possible to set a plurality of set times to enable the heating to be switched on for more than one period per day. If desired, more than one temperature sensor inside the building may be provided throughout the building and the mean temperature in the building calculated by the control device 9. Similarly, more than one temperature sensor may be provided externally of the building and the mean external temperature of the building calculated by the control device 9.

Claims

1. A method of controlling a building environment including the steps of sensing the wind speed and/or direction outside the building, with wind sensing means, feeding a signal from said wind sensing means to a control device sensing the temperatures inside and outside the building by temperature sensing means feeding a signal from the temperature sensing means to the control device, the control device utilising the signal from the wind and temperature sensors to calculate an optimum "on" time to start heating the building before a first set time so that the building environment is heated to a first predetermined temperature at the first set time, and/or an optimum "off" time to stop heating a building before a second set time so that the temperature of the building environment does not fall below a second lower predetermined temperature, by the second set time.

2. A method according to Claim 1 wherein the wind speed and/or direction and/or the temperatures inside and outside the building are each sensed continuously.

3. A method according to Claim 1 wherein the wind speed and/or direction and/or the temperatures inside and outside the building are sensed at regular periods.

4. A method according to Claim 1 wherein the temperatures inside and outside the building are sensed at intervals and the wind speed and/or direction is sensed continuously.

5. A method according to any one of the preceding claims wherein both the wind speed and the wind direction are sensed.

6. A method according to any one of the preceding claims wherein the constants of the building are utilised by the control device to calculate the optimum on and off times.

7. A building having means to sense the wind speed and/or direction outside the building, means to feed a signal from said wind sensing means to a control device, means to sense the temperature inside and outside the building, means to feed signals from said temperature sensing means to the control device, the control device being adapted to utilise the signals from said wind and temperature sensing means to calculate an optimum "on" time to start heating the building before a first set time so that the building environment is heated to a first predetermined temperature at the first set time, and/or an optimum "off" time to stop heating a building before a second set time so that the temperature of the building environment does not fall below a second lower predetermined temperature, by the second set time.

8. A building according to Claim 7 wherein the building constants are programmed into the control device.

9. A building according to Claim 7 wherein the control device incorporates a self learning device which determines the building constants depending on the performance of the building environment to the calculated heating on and off times.

10. A control device for use in a building according to any one of Claims 7 to 9.

11. A building, the environment of which is controlled by a method according to any one of Claims 1 to 6.

12. A method of controlling a building environment substantially as herein described with reference to and as shown in the accompanying drawings.

1 3. A building substantially as herein described with reference to and as shown in the accompanying drawings.

14. Any novel feature or novel combination of features disclosed herein and/or shown in the accompanying drawings.