GB2243438A - Apparatus for controlling the interior temperature of a vehicle - Google Patents

Abstract

Apparatus (1) for controlling the interior air temperature of a confined space, such as, the passenger/driver compartment of a vehicle, comprising fan means (7) arranged to circulate air whose temperature is to be controlled, a thermoelectric device (4) and means (6, 13) arranged to direct air being circulated by said fan means (7) onto the thermoelectric device (4). The device (4) is preferably made of a quaternary alloy of bismuth, tellerium, selenium and antimony with small amounts of suitable dopents to provide an oriented polycrystalline ingot with superior anisotropic thermoelectric properties. In disc-shaped form, the device (4) has one part heated and another part cooled when a d.c. voltage of one polarity is applied across it, with the one part being cooled and the other part being heated when the polarity of the d.c. voltage is reversed. <IMAGE>

Description

AIR TEMPERATURE CONTROL APPARATUS DESCRIPTION This invention relates to apparatus for controlling the air temperature within a confined space and is especially, but not exclusively, related to such apparatus for controlling the interior air temperature of the passenger/driver compartment of a vehicle.

If, on the one hand, a vehicle is parked for any length of time with its air conditioning unit switched off, out of doors in hot climatic conditions, then the interior air temperature of the passenger/ driver compartment can rise considerably and, in certain circumstances, to such an unbearable degree that the driving seat and steering wheel, as well as other driving components of the vehicle, become too hot to use. This experience is common to many drivers, especially in tropical regions, and in such cases, before next use of the vehicle, a driver has to open wide the vehicle doors, turn on the air conditioning unit and wait for quite a long time before the interior vehicle heat has dissipated and the driving and/or passenger seats and steering wheel are once again usable at a reasonable temperature.

If, on the other hand, a vehicle is parked for any length of time with its heating unit turned off, in the open air in cold climatic conditions, then the interior air temperature of the passenger/driver compartment can drop to such an extent that the driving/ passenger seats, steering wheel and other driving components become too cold to use comfortably. In such a case, a driver has to turn on the heating unit, usually after the vehicle engine has been warmed up, to gradually increase the interior air temperature of the passenger/driver compartment, before being able to drive the vehicle at a comfortable interior operating temperature.

In the light of these disadvantages, it is an object of the present invention to provide air temperature control apparatus which solves, or at least substantially reduces, such problems by maintaining the interior air temperature of an unused passenger/ driver compartment of a vehicle, or other confined space, at a level which will be comfortable for subsequent use by a driver or other user.

Thus, one aspect of the present invention resides in apparatus for controlling the interior air temperature in a confined space, such as, the passenger/ driver compartment of a vehicle, which apparatus comprises: (1) means arranged to circulate air whose temperature is to be controlled; (2) a thermoelectric device (as hereinafter defined); and (3) means arranged to direct air being circulated by said first-mentioned means onto the thermoelectric device.

Preferably, the air circulating means, thermoelectric device and circulating air directing means are located within a housing, with the circulating means being constituted by an electric fan. An air intake and an air exhaust, preferably in the form of a cascade of outlets, in the housing are provided.

Throughout this specification, the term "thermoelectric device" is used in relation to a device in the form of a module of a particular material of which one part is heated and another part is cooled when a d.c. voltage of one polarity is applied across it, with the one part being cooled and the other part being heated when the polarity of the d.c. voltage is reversed. Typically, this type of thermoelectric device comprises a disc-shaped, low current, ceramic insulated module of a material which is a quaternary alloy of bismuth, tellurium, selenium and antimony with small amounts of suitable dopents, which has been processed to provide an oriented polycrystalline ingot with superior anisotropic thermoelectric properties. Metallised ceramic plates can afford maximum electrical insulation and thermal conductivity.

It is to be appreciated that another aspect of the invention provides a vehicle whose passenger/ driver compartment is fitted with air temperature control apparatus in accordance with the invention.

In order that the invention may be more fully understood, a preferred embodiment in accordance therewith will now be described by way of example and with reference to the accompanying drawings in which: Figure 1 is a perspective view of air temperature control apparatus for use in the passenger/driver compartment of a vehicle; Figure 2 is a section along the line A-A in Figure 1; Figure 3 is an exploded view of the apparatus shown in Figures 1 and 2; Figure 4 is a diagrammatic circuit of a power supply assembly for the apparatus of Figures 1 to 3; Figure 5 is a section along the line A-A of Figure 1, showing the apparatus in use with air circulation arrows shown; and Figure 6 is a cut-away elevation of a vehicle in whose passenger/driver compartment is installed the apparatus shown in Figures 1 to 5.

Referring first to Figures 1 and 2 of the drawings, apparatus 1 capable of heating or cooling air to control the interior air temperature of passenger/driver compartment of a vehicle 9 (Figure 6), comprises a base plate 3 having a central hole 10 closed by a thermoelectric device in the form of a disc-shaped module 4 which is mounted on the base plate 3 by means of a heat-insulating, U-cross-sectioned washer 12 located around the periphery of the central hole 10 in sealing engagement with the base plate 3. The heat-insulating washer 12 is located within an annular flange 11 whose outer diameter corresponds with the inner diameter of a housing 5 for connection thereto.

The outer surface(s) of the thermoelectric module 4 is an electrically-insulating, heat conducting ceramic with two power leads (not shown) arranged to provide a d.c. voltage across the module. With one voltage polarity, the upper part of the module 4 is heated and the lower part cooled. With the voltage polarity reversed, the upper part of the thermoelectric module 4 is cooled and the lower part heated. Reversability of the d.c. voltage applied across the module 4 is effected by means of a switch 25, as shown in the circuit diagram of Figure 4. Thus, in summer, the polarity of the switch 25, and hence the polarity of the d.c. voltage applied across the thermoelectric module 4 is such that the upper part of the module is cooled, whilst, in winter, the polarity of the switch 25 is reversed, such that the upper part of the module 4 is heated.

In the lower portion of the cylindrical wall of the generally circularly-cross-sectioned housing 5 is a plurality of downwardly inclined air intakes 13 above which are provided respective locating shoulders 14, 15 for an air deflector 6 in the shape of an inverted truncated cone and air circulation means indicated generally at 7. Seats 16 support a slanted, generally rectangular top 8 with angled guide slats 27 defining an array of air exhausts.

As shown in Figures 2, 3 and 5 of the drawings, legs 17 (only one shown) assist in supporting the truncated cone-shaped air deflector 6 above the flange 11, such that a space 18 is maintained between the lower open end 17 of the deflector 6 and the upper surface of the thermoelectric module 4, whereby air entering the apparatus housing 5 via the intakes 13 can pass through the space 18 and then upwardly through the housing 5, finally exiting therefrom through the exhausts 27 in the slanted top 8.

The air circulation means 7 comprises an annular support 19 whose outer ring 24 is located upon the upper shoulder 15 of the housing 5 and an electric fan consisting of a motor 20, which is mounted centrally of the support 19, and fan blades 21. Such mounting is effected by means of a motor seat 22 which is connected to the outer ring 24 by means of aerofoils 23 of the annular support 19.

The top 8 comprises a generally rectangular frame 26 supporting the angled guide slats 27 which are inclined at a given angle such that they extend generally parallel with the roof of a passenger/driver compartment of a vehicle 9 in which the apparatus 1 is fitted, as will be described in more detail hereinbelow.

Referring now to Figures 4 and 6 of the drawings, a power supply assembly indicated generally at 2, comprises a solar cell 28 locatable at a suitable position on the exterior of a vehicle 9 with which the apparatus 1 is associated, and/or the battery 29 of the vehicle itself, for supplying d.c. power to the associated circuit via a switch 30. In position "A" of the switch 30, the vehicle battery 29 can be charged by means of the solar cell 28, in position "B" the solar cell 28 supplies d.c. voltage to the thermoelectric module 4 and fan motor 20, and in position "C" the vehicle battery 29 is used for supplying power to the module 4 and motor 20.

In use, the air temperature control apparatus 1 is installed on the rear shelf of the vehicle 9, or any other suitable location, in an orientation wherein the angled exhaust slats 27 are capable of directing air circulated by the apparatus in a direction which is generally parallel to the plane of the roof of the vehicle 9, as shown by the arrows 31 in Figure 6.

Although only one air temperature control apparatus 1 is illustrated, two or more may be employed.

In summer, and with the switch 25 in the correct position so that the polarity of the d.c. voltage across the thermoelectric module 4 causes the upper part of the module to cool, air from the interior of the passenger/driver compartment of the vehicle 9 is circulated through the apparatus 1 by being drawn through the downwardly inclined intakes 13 and then being directed onto the cooled upper surface of the thermoelectric module 4 by means of the underside surface of the air deflector 6. The so-cooled air is then drawn upwardly through the lower central aperture 17 of the deflector 6 via the space 18 past the fan blades 21 and support 19 and subsequently returned to the compartment interior via the exhaust array in the top 8. Such cooled air controls the overall interior air temperature of the passenger/driver compartment to keep it at a comfortable level.

In winter, the position of the switch 25 is changed such that the polarity of the d.c. voltage across the thermoelectric module 4 is reversed, whereby the upper part of the module is now heated, rather than cooled. By this means, cold air being circulated by the apparatus 1 is directed onto the heated upper surface of the module 4 after entering the housing 5 via the downwardly inclined intakes 13 in the lower portion of the cylindrical wall thereof. The soheated air then passes through the space 18 and upwardly through the aperture 17 at the base of the deflector 6, past the circulation means 7 and back into the vehicle compartment via the exhaust array in the top 8.

Airflow in the apparatus 1 is shown clearly by the arrows in Figure 5, whilst the arrows 31 show the circulating air within the passenger/driver compartment of the vehicle 9, with the cooled/heated air exiting from the apparatus 1 being directed generally parallel to the roof of the vehicle, to provide a smooth air flow around the compartment towards the front seat 32 and the vehicle and back again to the air cooling/heating apparatus 1.

In this manner, the interior air temperature of the passenger/driver compartment of the vehicle 9 can be controlled and maintained at a comfortable level when the vehicle is parked for any length of time in hot or cold climatic conditions with its regular air conditioning/heater unit turned off.

It is to be appreciated that various modifications may be made to the inventive apparatus described above without departing from its scope, as defined in the appended claims. For instance, although the thermoelectric device may be in the form of a disc-shaped, low current, ceramic insulated module of a quaternary alloy of bismuth, tellerium, selenium and antimony, with small amounts of suitable dopents, providing an oriented polycrystalline ingot with superior anisotroplic thermoelectric properties, the device may be in any other suitable form which delivers the required heating/cooling effect. In the preferred embodiment described above, each module 4 contains 127 "couples", each couple element being 1.143 mm (.045 inches) in length and 1.4 mm square in cross-section.

However, other suitably practical configurations may, of course, be used.

Claims (18)

1. Apparatus for controlling the interior air temperature in a confined space, such as, the passenger/driver compartment of a vehicle which apparatus comprises: (1) means arranged to circulate air whose temperature is to be controlled; (2) a thermoelectric device (as hereinbefore defined); and (3) means arranged to direct air being circulated by said first-mentioned means onto the thermoelectric device.

2. Apparatus according to claim 1, wherein said air circulating means comprises a fan.

3. Apparatus according to claim 1 or 2 including an air intake and an air exhaust.

4. Apparatus according to claim 3, wherein the air intake comprises a plurality of downwardly-inclined holes extending through the wall of a housing in which the components of the apparatus are located, for directing air being circulated by said air circulating means towards the thermoelectric device.

5. Apparatus according to any of claims 1 to 4, wherein said air directing means includes an air deflector in the shape of an inverted truncated cone.

6. Apparatus according to claim 5, wherein the open lower end of the inverted truncated cone-shaped air deflector is spaced from the thermoelectric device to define a space therebetween for air being circulated through the apparatus.

7. Apparatus according to any of claims 3 to 6, wherein the air exhaust comprises a cascade of outlets in the top of a housing in which the components of the apparatus are located.

8. Apparatus according to claim 7, wherein the cascade of outlets is defined by a plurality of angled guide slats.

9. Apparatus according to claim 8, wherein the slats are so angled that, when the apparatus is suitably installed within a confined space whose interior air temperature is to be controlled, air exiting from the air exhaust is directed generally parallel with respect to the plane of the roof or other upper surface of the confined space.

10. Apparatus according to any preceding claim, wherein the thermoelectric device is a disc-shaped, low current, ceramic insulated module of a suitable thermoelectric material.

11. Apparatus according to any preceding claim, wherein the thermoelectric device is made of a quaternary alloy of bismuth, tellerium, selenium and antimony with small amounts of suitable dopents.

12. Apparatus according to any preceding claim, wherein the thermoelectric device is in the form of an oriented polycrystalline ingot.

13. Apparatus according to any preceding claim, wherein the thermoelectric device is located sealingly over a central aperture in a base plate of a housing in which the components of the apparatus are located.

14. Apparatus according to claim 13, wherein said sealing location of the thermoelectric device with respect to the central aperture is provided by a heat resistent element supporting the device and sealed to the base plate of the housing.

15. Apparatus according to any preceding claim arranged to be installed within the passenger/driver compartment of a vehicle.

16. Apparatus for controlling the interior air temperature in the passenger/driver compartment of a vehicle, substantially as hereinbefore described with reference to the accompanying drawings.

17. A vehicle in whose passenger/driver compartment is installed air temperature control apparatus according to any preceding claim.

18. A vehicle according to claim 18, wherein the apparatus is mounted upon the rear shelf of the passenger/driver compartment thereof.