GB2467946A

GB2467946A - Air conditioning system

Info

Publication number: GB2467946A
Application number: GB0902915A
Authority: GB
Inventors: Bernard Sampson; Richard Hunt
Original assignee: Honeywell Normalair Garrett Holdings Ltd; Honeywell UK Ltd; Honeywell Aerospace BV
Current assignee: Honeywell UK Ltd; Honeywell Aerospace BV
Priority date: 2009-02-20
Filing date: 2009-02-20
Publication date: 2010-08-25
Anticipated expiration: 2029-02-20
Also published as: GB2467946B; GB0902915D0

Abstract

An air conditioning system 10 is provided for conditioning supply air for use In a first apparatus 12, such as comprising a catalytic converter, where the air is heated. The heated supply air from the first apparatus 12 is then cooled for use in second apparatus 15, such as a vehicle cabin or a housing for electronic components. The system 10 includes an air cooler heat exchanger 20 and a reheater heat exchanger 30 in series with respect to the air supply path. A first air flow path is provided from a first supply air inlet 21 to a first air cooler outlet 22, and a second air flow path is provided from a warm supply air inlet 24 to a second, cool supply air, air cooler outlet 25 which provides the cool supply air for use in the second apparatus 15. The reheater heat exchanger 30 has a first air flow path from a first reheater air inlet 31 for receiving warmed supply air from the first air cooler outlet 22, to a first reheater air outlet 32, heated air from the first reheater air outlet 32 passing In use to the first apparatus 12, where it is further heated, and the reheater heat exchanger 30 has a second air flow path from a second reheater air inlet 34 which in use receives hot air from the first apparatus 12, and a second reheater air outlet 35, and warm supply air from the second reheater air outlet 35 passing to the warm supply air inlet 24 of the second air flow path of the air cooler heat exchanger 20.

Description

Title: Air Conditioning System

Description of Invention

This invention relates to an air conditioning system and more particularly bu not exclusively to an air conditioning system for a vehicle, such as a land based vehicle or an aircraft.

More generically air conditioning systems are known for conditioning supply air for use in a first apparatus, where the supply air is heated, and subsequently for use in a second apparatus downstream of the air conditioning system. The second apparatus for example may be a habitable space, or a housing containing electronic equipment which it is required to keep cool. S...

It is known to utilise a reheater heat exchanger to recover heat which has been S.. S added to the supply air by the first apparatus. Such a reheater heat exchanger is typically provided upstream of an air cooler heat exchanger to which the air from the reheater is fed, for cooling used working air which when warmed, in cooling the supply air, is then exhausted from the air conditioning system.

Thus the majority of external heat which is added to the supply air by the first apparatus, is rejected to the external environment, with the working air. This is inefficient.

According to a first aspect of the present invention we provide an air conditioning system for conditioning supply air for use in a first apparatus where the supply air is heated, and subsequently for use in a second apparatus downstream of the air conditioning system, the heated supply air from the first apparatus being cooled by the air conditioning system for use in the second apparatus, the air conditioning system including an air cooler heat exchanger having a first air flow path for supply air from a first supply air inlet to a first air cooler outlet, the supply air at the first supply air inlet being at an initial temperature, and the air cooler heat exchanger having a second air flow path from a warm supply air inlet to a second, cool supply air, air cooler outlet, the air in the second air flow path being cooled by the air in the first air flow path in the air cooler heat exchanger, and the second air cooler outlet providing the cool supply air for use in the second apparatus, the system further including a reheater heat exchanger, the reheater heat exchanger having a first air flow path from a first reheater air inlet to a first reheater air outlet, the first reheater air inlet receiving warmed supply air from the first air cooler outlet, and heated air from the first reheater air outlet passing in use to the first apparatus, where it is further heated, and the reheater heat exchanger having a second air flow path from a second reheater air inlet which in use receives hot air from the first apparatus, and a second reheater air outlet, the hot supply air heating the supply air flowing in the reheater heat exchanger first air flow path, and warm supply air from the second reheater air outlet passing to the warm supply air inlet of the second air flow path of the air cooler *S..

heat exchanger. * ** * * * * **

The present invention maximises the recovery of heat which is put into the supply air by the first apparatus by passing the air from the first air flow path of *S**.* the first air cooler outlet, to the first reheater air inlet of the reheater heat exchanger, before the air passes to the first apparatus, so that the supply air is pre-warmed by the hot air from the first apparatus in the reheater heat exchanger.

Moreover the same air is used as supply air for use in the first and second apparatus, and for cooling the air heated by the first apparatus.

In one embodiment, in addition to the first air flow path for supply air through the air cooler heat exchanger, there is a parallel third air flow path through the air cooler heat exchanger from a cool working air inlet to a warmed working air outlet.

It is known that in a heat exchanger to which hot or warm air is provided and in which the hot or warm air flows along an air flow path as it is cooled by cool working air, there is a temperature gradient along the air flow path.

Desirably the first air cooler outlet from the air cooler heat exchanger and the first reheater air inlet are immediately adjacent to one another.

In this way, the warmer air, from the first air flow path of the air cooler heat exchanger is provided to the reheater heat exchanger for heating, whilst the cool working air of the third air flow path of the air cooler heat exchanger provides maximum cooling of the supply air prior to its use by the second *:::: 15 apparatus. **S. * * S...

Although at least a portion of the warmed air from the warmed working air outlet of the of the air cooler heat exchanger which has provided maximum cooling of the supply air for its use by the second apparatus may be exhausted from the system via an exhaust outlet, the system rejects less of the heat which has been added to the supply air by the first apparatus than in prior art * proposals.

In one physical arrangement the cool working air and the supply air for the first air supply inlet of the air cooler heat exchanger, are derived from a common ambient air system inlet, where the supply and working air enters the system at ambient temperature. Alternatively, the cool working air may be derived from a separate air inlet to the supply air, for example cool air from the second apparatus.

In the former case though, the cool working air and the supply air ft.

air supply inlet of the air cooler heat exchanger, may each be provid respective cool working air inlet and first supply air inlet of the air cook exchanger via a manifold to which ambient air is supplied.

The supply air for the first air supply inlet of the air cooler heat exchanger, least, may be at ambient temperature so that the initial temperature of the supply air is ambient, but preferably, in order to recover yet more heat, at least a portion of the warmed air from the warmed working air outlet of the third air flow path of the air cooler heat exchanger is mixed with the supply air upstream of the first supply air inlet of the air cooler heat exchanger.

Thus the initial temperature of the supply air which enters the first air flow path of the air cooler heat exchanger may be above ambient temperature, although would need to be cooler than the warmed supply air entering the second air flow path through the air cooler heat exchanger from the reheater heat exchanger. 0 SI * S * * S.

Although if desired the first and third air flow paths through the air cooler heat exchanger may be physically separated from one another in the air cooler heat * 0 exchanger e.g. by one or more dividing members, with the first reheater air : inlet immediately adjacent the first air cooler outlet, no such physical dividing member may be required, but the first and third air flow path flows may be established by separating the respective first air cooler air outlet and the warmed working air outlet, from the air cooler heat exchanger.

In a second embodiment, the reheater need not be immediately adjacent the first reheater air inlet. Again, the same air which flows through the first air flow path of the air cooler heat exchanger may be used both as supply air by the first and second apparatus, and as the working air in the air cooler heat S 5 exchanger for cooling the supply air. In the second embodiment, the is used as both supply and working air is preferably air which enters air supply inlet of the air cooler at substantially ambient temperature.

In this second embodiment between the first air cooler outlet and the reheater air inlet there may be a path to an exhaust outlet from the systel through which a portion of the supply air which has been warmed in the first air flow path of the air cooler heat exchanger is exhausted, Again the arrangement provides for less heat rejection than in prior art proposals.

The supply air in the second air flow path of the reheater heat exchanger may be constrained to flow in a first direction transverse to the flow direction of tI-ie supply air in the first air flow path, and then a second direction transverse to the supply air in the first air flow path, for maximum heat exchange efficiency Desirably, the first and second directions are substantially parallel to each other, the second air flow path of the reheater heat exchanger including a reversing section in which the flow direction of the supply air flowing in the second air flow path is reversed from the first to the second direction. * .a

Thus the reheater heat exchanger construction provides for maximum recovery of the heat from the hot air from the first apparatus.

According to a second aspect of the invention we provide in combination, an air conditioning system according to the first aspect of the invention and a first apparatus, wherein the first apparatus includes a heater for further heating the heated air from the first reheater air outlet, and a processor for using the further heated hot air, whereby the hot air which is provided to the second reheater air inlet is hotter than the heated air provided to the first apparatus However the hot air provided to the second reheater air inlet may be less hot than the hot air prior to use by the processor.

For example only, the processor of the first apparatus may include a catalytic converter.

According to a third aspect of the invention we provide in combination, an air conditioning system according to the first aspect of the invention and a second apparatus, wherein the second apparatus includes an enclosure which encloses one of a habitable space and a housing into which the cool supply air from the air conditioning system is provided.

For example the enclosure includes one of a habitable space being a vehicle cabin, and a housing containing electronic components. * S S

S'.. According to a fourth aspect of the invention we provide a vehicle having an air

S

conditioning system according to the first aspect of the invention, or a * ,e combination according to either of the second or third aspects of the invention.

Embodiments of the invention will now be described with reference to the * .5I accompanying drawings in which:-FIGURE 1 is a diagram of a first embodiment of an air conditioning system in accordance with the invention; FIGURE 2 is an illustration of an air cooler heat exchanger and reheater heat exchanger of the air conditioning system of figure 1; FIGURE 3 illustrates a temperature gradient of air as the air is cooled in a cross flow kind of air cooler heat exchanger which may be used in the system of figure 1; AGURE 4 is a diagram of a second embodiment of an air conditioning system according to the invention.

Referring to figure 1 there is shown an air conditioning system 10 for a vehicle.

The system 10 in use, conditions supply air for use in a first apparatus 12 and subsequently for use in a second apparatus 15 downstream of the air conditioning system 10. In this example, the first apparatus 12 includes a processor 13 which may be a catalytic converter. Air for use by the catalytic converter 13 is required to be heated to a hot working temperature, and accordingly the first apparatus 12 further includes a heater which is illustrated at 14.

The second apparatus 15 may include an enclosure being one of a habitable space such as a vehicle cabin, and a housing e.g. for electronic components, or any other second apparatus which requires a supply of cooled air, for example to maintain the temperature within a desired temperature range. * ** * S * * **

The air conditioning system 10 conditions the supply air by pre-warming the supply air prior to its heating by the heater 14 of the first apparatus 12, and 20 then cools the supply air for use by the second apparatus 15.

The air conditioning system includes an air cooler heat exchanger 20. This is of the cross flow type having one or more first passages which provide a first air flow path for supply air from a first supply air inlet 21 to a first air cooler outlet 22. The supply air at the first supply air inlet 21 is at an initial temperature which may be ambient temperature, or as described below a higher temperature than ambient.

The air cooler heat exchanger 20 further has one or more second passages, which provide a second air flow path which crosses the first air flow path and thus establishes a heat exchange relationship between initially warmer air flowing in the second air flow path and initially cooler air flowing in the first air flow path. The second air flow path is from a warm air supply inlet 24 to a second, cool supply air, air cooler outlet 25, the initially warm air in the second air flow path being cooled by the air in the first air flow path in the air cooler heat exchanger 20 as it flows, and the second cool supply air outlet 25 providing the cool air for use downstream in the second apparatus 15.

The system 10 further includes a reheater heat exchanger 30, again which may be of the cross flow kind. The reheater heat exchanger 30 has, established by one or more passages in the reheater heat exchanger 30, a first air flow path from a first reheater air inlet 31 to a first reheater air outlet 32, the first reheater air inlet 31 receiving warmed supply air from the first air :. cooler outlet 22, and heated air from the first reheater air outlet 32 passing in use to the first apparatus 12, where it is further heated by the heater 14 in this

example. * I. * * * * **

The reheater heat exchanger 30 has a second air flow path, again established by one or more passages, from a second reheater air inlet 34 which in use **** receives hot air from the first apparatus 12, and a second reheater air outlet * 35, the cross flowing hot supply air from the first apparatus 12 in the second air flow path heating the supply air flowing in the reheater heat exchanger 30 first air flow path from the first reheater air inlet 31 to the first reheater air outlet 32.

The warm supply air (i.e. hot air from the first apparatus 12 which has been cooled in the second air flow path of the reheater heat exchanger 30) from the second reheater outlet 35 is passed via a conduit 36 to the warm supply air inlet 24 of the second air flow path of the air cooler heat exchanger 20. * 9

The air cooler heat exchanger 20 of the embodiment shown in figure 1, in addition to the first air flow path for supply air through the air cooler heat exchanger 20, from first supply air inlet 21 to first air cooler outlet 22, has a parallel third air flow path through the air cooler heat exchanger 20 from a cool working air inlet 38 to a warmed working air outlet 39.

As illustrated in figure 3, It is known that in a heat exchanger 20 to which warm (or hot) air is provided at a warm supply air inlet 24, as the warm (or hot) air flows along a second air flow path towards a second cool air air cooler outlet 25, as it is cooled by cool working cross-flowing air flowing in a first air flow path, there is a temperature gradient along the second air flow path. Adjacent the warm (or hot) air inlet 24 the supply air in the second air flow path will be the warmest, and adjacent the second cool air outlet 25, the supply air in the *:::: second air flow path will be the coolest. Between these two extremes there will be a temperature gradient. Correspondingly, there is a temperature gradient *..* along the second cooling air flow path too, with the warmest cooling supply air from air cooler inlet 21, as it leaves the heat exchanger 20, being adjacent the warm (or hot) air supply inlet 24, as indicated by the reference 12H, and the coolest cooling supply air exiting the heater exchanger 20, being adjacent the S....

second cool air outlet 25, as indicated by the reference IC As indicated in figure 1, in this embodiment the first air cooler outlet 22 from the air cooler heat exchanger 20 and the first reheater air inlet 31 are physically immediately adjacent to one another. Thus it is the warmest supply air only from the first air flow path, indicated along the temperature gradient by the air at temperatures 12H to TH, which is passed immediately into the first reheater inlet 31 of the reheater heat exchanger 30.

The cooler working air i.e. that of the third air flow path of the air cooler heat exchanger 20 from cool working air inlet 38 to warmed working air outlet 39, which air is indicated along the temperature gradient at temperatures 10 to 6C, is not passed to the reheater heat exchanger 30, but provides maximum cooling of the supply air prior to its use by the second apparatus 1 5.

As can be seen from figure 1, at least a portion of the warmed air from the warmed working air outlet 39 of the air cooler heat exchanger 20 which has provided maximum cooling of the supply air for its use by the second apparatus 15, is exhausted from the system 10 via an exhaust outlet 40. A fan 41 is illustrated to assist exhausting of the warmed working air, but such fan 41 may not always be required.

In figure 3, for illustration, the air cooler heat exchanger 20 and reheater heat exchanger 30 are drawn separately, but from this description, and figure 1, it will be understood that desirably these two heat exchangers 20, 30 are in physical contact, and may be provided by a unitary device.

Referring to figure 2 such a unitary device is illustrated at 50. Similar parts to those identified in figure 1 already referred to are indicated by the same references. It can be seen in figure 2 that practically, the first air cooler outlet S.....

22 and first reheater inlet 31 conjoin.

The device 50 includes a system inlet 52 for fresh ambient air at ambient temperature, which system inlet 52 provides both supply air to the air cooler heat exchanger 20, and working air, via a common manifold which is indicated at 53. The air cooler heat exchanger 20 may not thus have differentiated first supply and cool working air inlets 21, 38 as suggested by the figure 1 diagram.

However the air cooler heat exchanger 20 does have differentiated first air cooler outlet 22 (connected directly to the reheater heat exchanger 30) and warmed working air outlets 39, and thus the air flow through the air cooler heat exchanger 20 will be separated functionally as hereinbefore described, with * 11 warmer, supply air (temperature gradient 12H to 7H) passing to the reheater heat exchanger 30, and cooler warmed working air (temperature gradient 1C to 6C) being exhausted from the system 10 by the exhaust outlet 40.

If desired, to improve separation of the supply and working air flows within the air cooler heat exchanger 20, a physical dividing member e.g. as indicated at in figure 1 only, may be provided, with one or more passages containing the air of the second air flow path through the air cooler heat exchanger 20 passing through such dividing member 55.

In a modification illustrated in figure 1, the supply air may if desired be warmed above ambient temperature before entering the air cooler heat exchanger 20 via the first supply air inlet 21, i.e. upstream of the first supply air inlet 21, by providing a portion of the warmed working air from warmed working air outlet 39 of the third air flow path of the air cooler heat exchanger 20 for mixing with the supply air within the manifold 53 via a conduit 37. An inlet port P to the manifold 53 for this provision is not shown in figure 3, but is indicated in figure 1.

S

*5S*S* * 20 Desirably the COO! work:ng ar s not warmed pr!or to passing into the cool working air inlet 38 of the air cooler heat exchanger 20, and thus with the modification described, some physical means of separating the ambient air from ambient air inlet 52, within the manifold 53 (where this is provided) into cool working air and warmed supply air would be required.

Warming the supply air in the manner described improves the efficiency of the air conditioning system 10, and allows more heat recovery from the hot air from the first apparatus 12.

Thus the initial temperature of the supply air which enters the first air flow path of the air cooler heat exchanger 20 may be above ambient temperature, although would need to be cooler than the warmed supply air entering the second air flow path through the air cooler heat exchanger 20 from the reheater heat exchanger 30.

Referring now to figure 4, another embodiment of the invention is shown, with similar parts to those illustrated in figure 1 being indicated by the same references. In this embodiment, the reheater heat exchanger 30 first reheater air inlet 31 is not immediately adjacent the first air cooler air outlet 22.

Moreover the ambient air which enters the system 10 is not split into supply air and working air, but rather, the same air which flows through the first air flow path of the air cooler heat exchanger 20 from first air supply inlet 21 to first air cooler outlet 22 is used both as supply air by the first 12 and second 15 apparatus, and as the sole working air in the air cooler heat exchanger 20 for cooling the supply air. * ** * * * * **

Between the first air cooler heat exchanger outlet 22 and the first reheater air inlet 31 there is a conduit 60 from which branches a path to the exhaust outlet *S, 0 40 from the system 10 (via a fan 41)through which path a portion of the supply * air which has been warmed in the first air flow path of the air cooler heat exchanger 20, in the first air flow path from first supply air inlet 21 to first air cooler outlet 22, is exhausted.

The first and second air flow paths through the reheater heat exchanger 30 may be in respective transverse passages.

In the arrangement shown in figure 4, the reheater heat exchanger 30 is modified compared to the reheater exchanger 30 of figure 1 in that the supply air in the second air flow path of the reheater heat exchanger 30, i.e. the hot supply air returned from the first apparatus 12 which flows from the second reheater inlet 34 to the second reheater outlet 35, is constrained to flow first in a first direction transverse to the flow direction of the supply air in the first air flow path, and then a second direction transverse to the supply air in the first air flow path flowing from the first reheater inlet 31 to the first reheater outlet 32.

The first and second directions are substantially parallel to each other in the example, the second air flow path of the reheater heat exchanger 30 including a reversing section 58 in which the flow direction of the supply air flowing in the second air flow path is reversed from the first to the second direction.

Various modifications are possible without departing from the scope of the invention, in addition to those already mentioned.

::..: 15 For example, in figure 1 a furtherfan is indicated at 11, the furtherfan 11 being part of the first apparatus 12, the further fan 11 assisting the flow of supply air from the first air outlet 32 of the reheater heat exchanger 30 to the heater 14 and processor 13 of the first apparatus 12. Such further fan 41 may not always be required, or may be part of the air conditioning system 10.

The first apparatus 12 is described in the examples as including a catalytic converter but the invention is applicable to supplying pre-warmed air to any other apparatus where the apparatus itself adds heat energy to the air, which added heat then needs to be recovered so that cooler air is available for downstream use. By using the recovered heat to warm supply air for use in the first apparatus 12, the amount of heat which needs to be added to the supply air by the first apparatus 12 may be minimised thus resulting in a considerably energy saving over known proposals.

Whereas the second apparatus 15 has been described as one of a habitable space and a housing for e.g. heat sensitive electronic components which need to maintained cool within a specified temperature range, the invention may be applied where the second apparatus 15 is any apparatus which requires to be provided with a supply of cool air.

In another embodiment, which is a modification of the figure 1 embodiment, cool working air for the third airflow path, need not be all ambient air, but may, at least in part, be cool air derived from the second apparatus 15. This supply of cool working air may be separate from the supply air for the first air flow path.

Where the second apparatus 15 includes one of a habitable space and a housing, or other enclosure, these need not be provided on a vehicle. S...

S..' The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any :: 20 combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

CLAIMS1. An air conditioning system for conditioning supply air for use in a first apparatus where the supply air is heated, and subsequently for use in a second apparatus downstream of the air conditioning system, the heated supply air from the first apparatus being cooled by the air conditioning system for use in the second apparatus, the air conditioning system including an air cooler heat exchanger having a first air flow path for supply air from a first supply air inlet to a first air cooler outlet, the supply air at the first supply air inlet being at an initial temperature, and the air cooler heat exchanger having a second air flow path from a warm supply air inlet to a second, cool supply air, air cooler outlet, the air in the second air flow path being cooled by the air in the first air flow path in the air cooler heat exchanger, and the second air :::: cooler outlet providing the cool supply air for use in the second apparatus, the system further including a reheater heat exchanger, the reheater heat exchanger having a first air flow path from a first reheater air inlet to a first reheater air outlet, the first reheater air inlet receiving warmed supply air from the first air cooler outlet, and heated air from the first reheater air outlet passing in use to the first apparatus, where it is further heated, and the reheater heat exchanger having a second air flow path from a second reheater air inlet which in use receives hot air from the first apparatus, and a second reheater air outlet, the hot supply air heating the supply air flowing in the reheater heat exchanger first air flow path, and warm supply air from the second reheater air outlet passing to the warm supply air inlet of the second air flow path of the air cooler heat exchanger.
2. A system according to claim 1 wherein in addition to the first air flow path for supply air through the air cooler heat exchanger, there is a parallel third air flow path through the air cooler heat exchanger from a cool working air inlet to a warmed working air outlet.
3. A system according to claim 2 wherein the first air cooler outlet from the air cooler heat exchanger and the first reheater air air inlet are immediately adjacent to one another.
4. A system according to claim 2 or claim 3 wherein at least a portion of the warmed air from the warmed working air outlet of the of the air cooler heat exchanger is exhausted from the system via an exhaust outlet.
5. A system according to any one of claims 2 to 4 wherein the cool working air and the supply air for the first supply inlet of the air cooler heat exchanger, are derived from a common ambient air system inlet, where the supply and working air enters the system at ambient temperature.

::::
6. A system according to any one of claims 2 to 4 wherein the cool working air is cool air from the second apparatus.
7. A system according to any one of claims 2 to 6 wherein the cool working air and the supply air for the first supply inlet of the air cooler heat * exchanger are each provided to the respective cool working air inlet and first **.S** * 20 supply air inlet of the air cooler heat exchanger via a manifold to which * ambient air is supplied.
8. A system according to any one of claims 2 to 7 wherein at least a portion of the warmed air from the warmed working air outlet of the third air flow path of the air cooler heat exchanger is mixed with the supply air upstream of the first supply air inlet of the air cooler heat exchanger.
9. A system according to any one of claims 2 to 8 wherein the first and third air flow paths through the air cooler heat exchanger are physically separated from one another in the air cooler heat exchanger.
10. A system according to any one of claims 2 to 8 wherein the first and third air flow path are being established by separating the respective first air cooler air outlet and the warmed working air outlet, from the air cooler heat exchanger.
11. A system according to claim 1 wherein between the first air cooler outlet and the first reheater air inlet there is a path to an exhaust outlet from the system through which a portion of the supply air which has been warmed in the first air flow path of the air cooler heat exchanger is exhausted.
12. A system according to claim I or claim 11 wherein the supply air in the second air flow path of the reheater heat exchanger is constrained to flow in a first direction transverse to the flow direction of the supply air in the first air flow path, and then a second direction transverse to the supply air in the first air flow path. * ** * S * * **
13. A system according to claim 12 wherein the first and second directions are substantially parallel to each other, the second air flow path of the reheater heat exchanger including a reversing section in which the flow direction of the * supply air flowing in the second air flow path is reversed from the first to the second direction.
14. An air conditioning system substantially as hereinbefore described with reference to and/or as shown in figures 1 and 2 or figure 4 of the accompanying drawings.
15. In combination, an air conditioning system according to any one of claims I to 14 and a first apparatus, wherein the first apparatus includes a heater for further heating the heated air from the first reheater air outlet, and a processor for using the further heated hot air, whereby the hot air which is provided to the second reheater air inlet is hotter than the heated air provided to the first apparatus.
16. A combination according to claim 14 wherein the processor of the first apparatus includes a catalytic converter.
17. In combination, an air conditioning system according to any one of claims 1 to 14 and a second apparatus, wherein the second apparatus includes an enclosure which encloses one of a habitable space and a housing into which the cool supply air from the air conditioning system is provided.
18. A combination according to claim 17 wherein the enclosure includes one of a habitable space being a vehicle cabin and a housing containing electronic components.
19. A vehicle having an air conditioning system according to any one of claims 1 to 13, or a combination according to any one of claims 15 to 18. e..** 20
20. Any nove! feature or novel combination of features described herein and/or as shown in figures 1 and 2 or figure 4 of the accompanying drawings.