GB2198227A

GB2198227A - Energy conservation system and method

Info

Publication number: GB2198227A
Application number: GB08625521A
Authority: GB
Inventors: Anthony Rack
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-10-24
Filing date: 1986-10-24
Publication date: 1988-06-08
Also published as: GB8625521D0

Abstract

A method and system particularly in relation to buildings, comprises the use of heated or cooled air which is normally extracted from the inside of a building (10) and expelled from which the energy is extracted then applied to cavities between the room and the outside. This results in very low equipment and installation costs and minimal maintenance requirements. <IMAGE>

Description

ENERGY CONSERVATION SYSTEM AND METHOD The present invention relates to a method and system for energy conservation particularly in relation to buildings.

It has previously been proposed to reduce heat lose from buildings by supplying heated air to the cavity of external cavity walls and/or roofs and floors. Such an arrangement is disclosed in German Offenlegungsschrift 29 29 070. However, this previous proposal can really be considered as an extension of the early Roman underfloor heating techniques. These heated air systems have the major disadvantage of requiring the supply of energy to heat the air. Furthermore, installation and maintenance costs are high.

In contrast, cavity wall or other cavity insulation consisting of filling the cavity with an insulating material is of moderate installation cost and is maintenance free. The reduction in heat lose is directly comparable with that obtained by the heated air system. Consequently, for the above stated reasons and difficulty of installation the heated air system has not been adopted widely as a means of insulation or heating.

According to a first aspect of the present invention there is provided an energy conservation system comprising means for collecting air to be expelled from a building and means for supplying energy from the collected air to a cavity between the inside and the outside of the building.

According to a second aspect of the present invention there is provided a method of energy conservation comprising the steps of collecting air to be expelled from a building and supplying energy from the collected air to a cavity between the inside and the outside of the building.

Preferably, in both the system and method of the present invention, the collected air is itself supplied directly to the cavity, although where necessary filtration or heat exchange techniques can be included. That is, the collected air can be used directly or fresh air, either warmed or chilled by a heat exchanger, can be used.

It will be appreciated that the present invention mitigates the above described disadvantages of previous heated air systems. In addition, the present invention may be applied in circumstances where the air inside the building is held below the outside temperature, thus reducing the energy required to maintain the cooler temperature within the building.

The present invention does not require any additional input of energy in order to warm or chill air in the cavity, use is made of that portion of the initial energy input which would normally be wasted.

Embodiments of the invention will now be described by way of example only and with reference to the single figure of accompanying drawings which is a schematic partial section through a multi-storey housing development.

A particular application of the present invention will be described with reference to figure 1.

Figure 1 is a schematic representation of a partial section through a multi-storey housing development 10.

The building comprises an external wall 12 an internal wall 14 and a cavity 16 therebetween. Internally, the building 10 is divided into a number of units of accommodation each separated by a floor and ceiling 18.

In accordance with current building regulations, each unit of accommodation will include a number of rooms from which air extraction must be provided. Such rooms include kitchens and bathrooms. This air extraction facility is often provided on a centralised basis, generally from kitchen and bathrooms as indicated in figure 1. Each of the rooms concerned is provided with one or more grills 20 from which an extract duct or ducts 22 connects with a main duct 24. The main duct 24 is connected to the input of an extractor fan 26 usually located at the top of the building 10. Normally, the output from the extractor fan 26 is vented directly to the outside of the building.

In accordance with the present invention, a cowling 28 is applied to the output of the extractor fan 26.

Output from cowling 28 is fed via ducting 30 into cavity 16. If necessary, the extract air may be treated by a unit 32 provided in ducting 30. Unit 32 may be a simple de-humidifier and/or filter. If the extract air is particularly in need of cleansing, unit 32 may be in the form of a heat exchanger in which case heat from the unclean air is transferred to clean air within duct 30 and cavity 16 while the unclean air is kept separate therefrom. The unclean air is expelled to the atmosphere after passing through the heat exchanger.

An acceptable alternative to de-humidifying the air may be the addition of supplementary air of lower humidity.

It is to be noted that the only components required to implement the invention in the form shown in figure 1 are cowling 28 and ducting 30, with unit 32 being provided if necesssary. The ducting 22, 24 and extractor fan 26 are already provided as part of the initial construction of the building in many existing cases. Consequently, it will be appreciated that the cost of components to implement the present invention may be relatively low as are the associated installation costs. Furthermore, the additional components are essentially maintenance free and even with the inclusion of unit 32, only minimal maintenance should be required.

Air supplied to the cavity may exhaust therefrom via air bricks or grills 33, with or without the aid of extractor fans. If it is desirable for the air pressure within the cavity to be less than that outside the building, the main extraction fans may be dispensed with and cavity exhaust fans only used.

The arrangement may include air inputs to the cavity at any vertical level and similarly it is possible to provide the cavity exhaust outlets at any desired vertical level.

The extracted air may be ducted to a main duct or individual rooms may have air extracted therefrom individually into the cavity, with or without the use of extractor fans.

It is believed that the present invention can most successfully be applied to tower block accommodation, old peoples homes, offices factories and laboratories, etc. Application to single unit domestic housing is feasible but perhaps less cost justifiable since the relevant air extraction system is unlikely to form part of the original construction.

Current building regulations often require at least one complete air change per hour for habitable accommodation, with three air changes per hour in kitches and bathrooms. Such air changes may be continuous or intermitent. In the case of factory accommodation, the number of complete fresh air changes per hour can be as high as six and in some laboratories or other special use buildings the figure can be as high as thirty or more complete fresh air changes per hour.

As previous noted, the present invention is equally applicable to buildings in which the requirement is not the prevention of heat lose but rather the maintenance of a relatively cool environment within the building compared with the outside air temperature. In these circumstances, the invention functions without modification. Moreover, the arrangement automatically changes between heating cavity 16 compared with the outside air temperature to cooling cavity 16 as compared to the outside air temperature, directly in accordance with changes in temperature of the air on the inside of the building.

The present invention is applicable to both normally heated and normally refrigerated buildings.

It is to be noted that although the present invention is preferably used in conjunction with buildings having double shell such as existing cavity walls, cavity walling could be facbricated at the time of installing the necessary ducting The arrangement may still operate if the cavity is filled with a relatively porous material. Additionally, duct 30 could readily be adapted to feed a manifold such that the air from cowling 28 is feed to the cavity between the panes of glass in double glazing units.

In previously known arrangements, such as disclosed in the above mentioned German document, an air re-circulation technique is used. In the preferred form of the present invention, there is no re-circulation of the collected air.

Claims

1. An energy conservation system comprising means for collecting air to be expelled from a building and means for supplying energy from the collected air to a cavity between the inside and the outside of the building.

2. A system as claimed in claim 1, wherein the collected air is itself supplied to the cavity.

3. A system as claimed in claim 1 or 2, wherein the cavity is between walls.

4. A system as claimed in claim 1 or 2, wherein the cavity containS a relatively porous material.

5. A system as claimed in claim 1 or 2, wherein the cavity is between panes of glass.

6. A system as claimed in claim 2, further comprising means for filtering the collected air before supply to the cavity.

7. A system as claimed in claim 2, further comprising means for de-humidifying the air before supply to the cavity.

8. A system as claimed in claim 1, further comprising a heat exchanger which transfers energy between the collected air and air in the cavity.

9. A building including an energy conversation systsem as claimed in any preceding claim.

10. A building as claimed in claim 9 and having a centralised air extractor wherein said means for collecting air comprises a cowling connected to the centralised extractor.

11. A method of energy conservation comprising the steps of collecting air to be expelled from a building and supplying energy from the a collected air to a cavity between the inside and the outside of the building.

12. A method as claimed in claim 11, wherein the step of supplying energy from the collected air comprises supplying the collected air itself to the cavity.

13. A method as claimed in claim 11 or 12, wherein the step of supplying energy from the collected air comprises supplying the collected air to a cavity between the walls of a building.

14. A method as claimed in claim 11 or 12, wherein the step of supplying energy from the collected air comprises suppling the collected air to a cavity between panes of glass.

15. A method as claimed in claim 12, further comprising the step of filtering the collected air prior to supply to the cavity.

16. A method as claimed in claim 12, further comprising the step of de-humidifying the collected air prior to supply to the cavity.

17. A method as claimed in claim 11, comprising the step of passing the collected air through a heat exchanger.

18. An energy conservation system substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.

19. A method of energy conservation substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.