AU7193198A - Thermoelectric seat cooler and warmer - Google Patents

Description

AUSTRALIA

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THERMOELECTRIC SEAT COOLER AND WARMER The following statement is a full description of this Invention. Including the best method of performing it known to me: THERMOELECTRIC SEAT COOLER AND WARMER This invention relates to improvements in devices for applying Peltier Effect Thermoelectric modules to the cooling and heating of seats.

Peltier Effect Thermoelectric modules are thin wafer semiconductor devices that produce and maintain a cool face and a warm face when an electric current is applied to them; reversing the electric current flow reverses the heat flow.

Existing proposals use a fluid medium and pumps or blowers to transfer the 10 heat to or from the person on the seat to or from a heat exchanger attached to the Peltier Effect Thermoelectric modules. This invention obviates the need for this complexity by placing heat conducting plates or sheets onto the seat, with a number of Peltier Effect Thermoelectric modules attached to the opposite side, to directly cool or warm the occupant by conduction. It does not require a specially constructed seat. It can be applied to many existing seats with relatively simple modifications.

At present a common method of providing thermal comfort is by air conditioning. This invention offers the following advantages over air conditioning. It can provide thermal comfort without the need of an enclosed space. It is much more energy efficient because it adds or removes heat directly to or from the person instead of a large air mass. It is much more rapid in effect with no waiting for the whole space to cool or warm. It provides individuals direct control of their own comfort level, and it allows, and even benefits from, unlimited circulation of fresh air.

The human body struggles to maintain a constant temperature in very hot or very cold conditions and this causes a feeling of discomfort. A comforting relief can be found by contact with a cool or a warm surface similar to a dog or a cat lying on a cool slab on a hot day. When seated, the large surface area of the occupant in contact with the seat can be used to add or remove heat by conduction and thus provide comfort.

Since the human body normally produces about 100 watts of thermal power, a relatively small amount of low voltage direct current electrical power can be used in thermoelectric modules to achieve a pleasant effect particularly in motor vehicles where such power is usually available in sufficient quantity.

The present invention provides a number of Thin Flexible Sheets of Heat Conducting Material attached on to or near the surface of a seat so as to be 9 in close contact with the occupant of that seat, with each sheet having a number of Peltier Effect Thermoelectric Modules attached onto the opposite or inside surface of that sheet so that the said Peltier Effect Thermoelectric Modules may effectively transfer heat between the said sheet and Heat 0:"i Radiating and Convecting Devices attached to the opposite sides of those Peltier Effect Thermoelectric Modules.

The said Heat Radiating and Convecting Devices are arranged to transfer the said heat to or from the surrounding air so that when an electric current is applied to the said Peltier Effect Thermoelectric Modules, heat flows to or from the occupant of the seat, that effect being generally proportional to the quantity of the electric current applied and the temperature differential maintained between the surfaces of the said Peltier Effect Thermoelectric Modules.

The size and number of the said Peltier Effect Thermoelectric Modules can be selected to achieve a balance between the desire to achieve an even heat distribution to or from the said Thin Flexible Sheets of Heat Conducting Material, and the costs of attaching and connecting those modules, and the need to provide a supporting structure of sufficient strength.

The structure of the seat which supports the said Thin Flexible Sheets of Heat Conducting Material is used to provide an insulating effect to direct 10 the heat movement either towards the occupant of the seat or towards the Peltier Effect Thermoelectric Modules as the case may be.

If the space behind the seat surface is enclosed by the structure of the seat, the effect and efficiency of the seat over a period of time will be enhanced by the circulation of air from outside that space to maintain a good 15 temperature differential between the surfaces of the said Peltier Effect Thermoelectric Modules.

If the said electric current applied to the said Peltier Effect Thermoelectric Modules is arranged to provide a heating effect to the said Thin Flexible Sheets of Heat Conducting Material, the corresponding cooling effect on those Heat Radiating and Convecting Devices attached to the opposite side of the said Peltier Effect Thermoelectric Modules may produce condensation of water vapour which may freeze. If this is a problem in some applications, existing technology may be used to collect and remove the condensate and materials selected to resist corrosion and dampness. This effect may also be compensated for by heating the air in contact with the said Heat Radiating and Convecting Devices attached to the opposite side of the said Peltier Effect Thermoelectric Modules and thus raising the relative humidity to the point where condensation would not occur.

Existing technology can provide various means of providing a smooth Direct Current electrical supply to the said Peltier Effect Thermoelectric Modules at the required voltage and of regulating that current manually, or automatically in response to ambient air temperature via a thermostat.

A refinement of such automatic regulation is the use of a sensor, tuned to respond to the wavelengths of infared radiation produced by a human body, 10 and placed to measure such radiation actually being produced by the occupant of the seat and thus being able to more effectively control the cooling or heating effect of the seat in response to the variations in the individual human metabolism and to such factors as the thickness of clothing being worn at the time. Such a sensor may also be used to activate the seat automatically.

The Diagram, Figure 1, shows a cross sectional view through the seat at the place where one of the many Peltier Effect Thermoelectric Modules is mounted to show how they perform their function according to this invention.

Referring to Figure 1, it can be seen that the Peltier Effect Thermoelectric Module, 1 is attached to a Thin Flexible Sheet of Heat Conducting Material and has finned heat conducting material attached to its other face, and is in a hole in the insulating material which surrounds it. The electrical wires of the module protrude and are connected to other wires leading to the control unit. A decorative material may be attached to the Thin Flexible Sheets of Heat Conducting Material and serve to add more strength to that layer. The left of the figure is where the occupant makes contact with the seat and the right of the figure is the space behind the seat surface and any insulating or padding material.

In one form the invention is designed to be readily adapted to some existing vehicle seats. In this form the said Thin Flexible Sheets of Heat Conducting Material consist of chemically pure copper which has excellent heat 10 conducting properties and sufficient ductility and flexibility to be glued onto the seat surface and to be comfortably sat upon. The size and shape of the individual sheets is the same as the sections of the seat panels to which they *o are glued, with the borders generally conforming to the sewing pattern of the seat upholstery to prevent any tendency of the said sheets to fatigue, stretch or tear along those lines of upholstery. The thickness of the said copper sheet is selected to be a balance between the need to distribute heat evenly and to be mechanically strong, which requires more thickness and the need to be flexible and comfortable to sit on which tends to favour less thickness. The said copper sheet may be reinforced internally, externally, or as a laminate, with a fibrous material.

Before the said copper sheets are glued to the seat surface, the said Peltier Effect Thermoelectric Modules are soldered to the rear of them in an even pattern which does not conflict with any supporting springs or other structure beneath the surface of the seat padding where they are to be mounted and so that the holes can be cut into the seat beneath them.

The said Peltier Effect Thermoelectric Modules have metallic fins [3] soldered to their rear surface of sufficient dimension to protrude through the said holes cut into the seat upholstery and padding and thus conduct sufficient heat away from or towards those Peltier Effect Thermoelectric Modules and transfer it to or from the surrounding air.

The size and shape of the holes generally conforms to the flat side of the said Peltier Effect Thermoelectric Modules A certain amount of flexibility in the material of the said metallic fins [31 is beneficial in preventing them from transferring mechanical stress to the Peltier Effect Thermoelectric Modules in the event that movement in the seat surface causes them to contact the internal frame work of the seat.

The original surface and padding of the said existing vehicle seat is used as .the insulating layer The weakening of the seat caused by the cutting of holes in it's surface is compensated for by the reinforcement provided in using a strong glue to attach said Thin Flexible Sheets of Heat Conducting Material to it's surface.

The structure of the said seat in this form of the invention will need to allow the said Heat Radiating and Convecting Devices sufficient contact with the ambient air by fans or blowers if necessary.

In another form of the invention a seat may be manufactured to include the invention described in Figure 1 into it's structure. In this case the said Thin Flexible Sheets of Heat Conducting Material can form the surface of the seat itself or be attached beneath a layer of material such as leather, vinyl, or cloth and be supported by a single or multiple layer of plastic foam which has been selected for a combination of insulating and cushioning properties.

The seat mentioned in this form of the invention may be designed and manufactured to permit the said Heat Radiating and Convecting Devices attached to the opposite side of the said Peltier Effect Thermoelectric Modules sufficient contact with the ambient air so that circulating fans are not required to maintain a sufficient temperature differential across the surfaces of the said Peltier Effect Thermoelectric Modules.

In another form of the invention a seat may be manufactured to include the invention as described in Figure 2.

In the diagram Figure 2 a cross section is shown through three of the Peltier Effect Thermoelectric Modules with the item numbers corresponding to the 15 numbers of items in Figure 1 which perform the same function The left of the figure is where the occupant makes contact with the seat and the right of the figure is the space behind the seat surface.

The Peltier Effect Thermoelectric Modules in Figure 2 are sandwiched between two Thin Flexible Sheets of Heat Conducting Material in Figure 2 and in Figure 2, and bonded to them, with the inside layer [3] performing the function of the Heat Radiating and Convecting Devices [3] described in Figure 1. These sheets are glued to the insulating layer in Figure 2 to form the same dimension of thickness as between the faces of the said Peltier Effect Thermoelectric Modules in figure 2 which are accommodated within holes in Figure 2 formed into that insulating layer. The electrical wires in Figure 2 are lead out through holes 8 in the rear Thin Flexible Sheets of Heat Conducting Material in Figure 2 and connected to leads to an electrical control unit.

In the seat mentioned in this form of the invention, the invention as described in Figure 2 would separately form the entire vertical surface of the seat and the entire horizontal surface of the seat and be moulded and shaped to be comfortably sat upon. When forming the seat surface, the invention would need to be supported by mechanical springs instead of upholstery foam to permit the inside surface, 3 Figure 2 to effectively 10 radiate and convect the heat transferred to or from the Peltier Effect S Thermoelectric Modules Figure 2.

As in the other forms of the invention the seat mentioned in this form of ooo the invention may be constructed to expose the Heat Radiating and Convecting Device in Figure 2 to sufficient ambient air to maintain a sufficient temperature differential across the said Peltier Effect Thermoelectric Modules or alternatively have fans mounted to circulate air from outside the structure and enclosure of the seat.

Claims (9)

1. A seat cooling and heating device comprising Thin Flexible Sheets of Heat Conducting Material attached on to or near to the surface of a seat so as to be in close contact with the occupant of that seat, with each sheet having a number of Peltier Effect Thermoelectric Modules attached to the opposite side to the side in contact with the said occupant and with a Thermal Insulating Material attached to the area surrounding the said Peltier Effect Thermoelectric Modules so that they will, in response to an electric current applied to them, actively transfer heat between the 10 said Thin Flexible Sheets of Heat Conducting Material and Heat Radiating and Convecting Devices attached to the opposite side of each said Peltier Effect Thermoelectric Module, and thus to or from the surrounding air.

2. The Heat Radiating and Convecting Devices attached to the opposite side of each Peltier Effect Thermoelectric module in claim 1 may conform to the flat area of the said Peltier Effect Thermoelectric Modules and project at right angles to that area and be of sufficient length to transfer sufficient heat to the air behind the Thermal Insulating Material in claim 1.

3. The Heat Radiating and Convecting Devices attached to the opposite side of each Peltier Effect Thermoelectric Module in claim 1 may consisting of a sheet of heat conducting material of the same or similar size and shape and material as the sheet of heat conducting material in contact with the occupant and be maintained parallel to that sheet by the layer of Thermal Insulating Material in claim 1, so that the said Peltier Effect Thermoelectric Modules and the said Thermal Insulating Material are sandwiched between parallel layers of flexible heat conducting material.

4. A seat is claimed to be constructed to incorporate the invention in claims 1 and 2 and providing the Heat Radiating and Convecting Devices attached to the opposite side of each Peltier Effect Thermoelectric Module in claims 1 and 2 with sufficient contact with the ambient air to maintain an efficient heat differential across the Peltier Effect *ii"i Thermoelectric Modules of claims 1 and 2 by means of fans or blowers if necessary.

5. A seat is claimed to be constructed so that the invention in the form in 15 claim 3 comprises the entire vertical and the entire horizontal surface of that seat with those surfaces being entirely supported by mechanical springs so as to provide the Heat Radiating and Convecting Devices S" attached to the opposite side of the Peltier Effect Thermoelectric Modules in claim 3 with sufficient contact with the ambient air to maintain an efficient heat differential across the Peltier Effect Thermoelectric Modules by means of fans or blowers if necessary.

6. A seat is claimed to be a seat adapted to accommodate the invention in the form in claim 2 by having holes constructed into the already existing surface and padding of that seat to contain the said Peltier Effect Thermoelectric Modules and the attached heat Radiating and Convecting Devices in claims 1 and 2, and to maintain a sufficient heat differential across the said Peltier Effect Thermoelectric Modules by means of fans or blowers if necessary and using the said already existing seat surface and padding as the Thermal Insulating Material in claim 1.

7. The electric current in claim 1 is claimed to be provided as a means of controlling the cooling and the warming effect of the invention by means of a suitable electronic device, such control being manual, or automatic in response to sensors, with appropriate safety features to prevent the seat from overheating or overcooling.

8. A sensor of claim 7 is claimed to be tuned to personal infared frequencies to respond to individual human metabolism's and the 15 thickness of clothing being worn and to automatically activate the electronic device of claim 7 if required to do so.

9. The Thin Flexible Sheets of Heat Conducting Material in claim 1 are claimed to consist in one form of high purity copper sheet which may be internally reinforced by fibrous material such as carbon fibre or glass fibre and may be externally reinforced by that or other material in cloth form in conjunction with a thermal adhesive or may be formed into a laminate with such materials. seats in claims 4, 5 and 6 may be designed or adapted to facilitate the warming of the occupant by collecting and removing any consequent condensate from the Heat Radiating and Convecting Devices of claims 1,2 and 3 and by the selection of damp resistant materials, or to prevent the formation of such condensate by heating the air in contact with the said Heat Radiating and Canvecting Devices. 11 A seat cooling and warming device and seats adapted or constructed to incorporate that device substantially as herein described with reference to 10 the accompanying drawings. o a GRANT ALEXANDER CAMERON LOCKIE 01 MAY 1998