Title:
Refrigeration device, arrangement, and use of controller thereof
Kind Code:
A1


Abstract:
A refrigeration device has a body having an interior, a first cooling device adapted to cool the interior of the body, a second cooling device adapted to cool the interior of the body using a cooling source, and a temperature controller adapted to participate in activating the first cooling device on the basis of availability of the cooling source and adapted to participate in activating the second cooling device on the basis of the availability of the cooling source. The second the cooling source may be exterior air from outdoors. In some embodiments, the second cooling device is used in lieu of the first cooling device when the exterior air is cold enough to cool the interior of the refrigeration device. In some embodiments, the refrigeration device has only one cooling device adapted to cool the interior using exterior air.



Inventors:
Pepin, Leo J. (Iroquois Falls "A", CA)
Application Number:
11/119779
Publication Date:
12/08/2005
Filing Date:
05/03/2005
Primary Class:
Other Classes:
62/229, 62/180
International Classes:
F25B1/00; F25B39/02; F25B41/00; F25B49/00; F25B49/02; F25D13/00; F25D17/00; F25D17/04; F25D29/00; F25B27/00; (IPC1-7): F25D17/00; F25B1/00; F25B41/00; F25B49/00; F25D17/04
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Primary Examiner:
NORMAN, MARC E
Attorney, Agent or Firm:
Le'o J. Pe'pin (IROQUOIS FALLS "A", ON, CA)
Claims:
1. An arrangement for a refrigeration device comprising: a first cooling device; a second cooling device; and a controller having a control function adapted to participate in activating the first cooling device based on availability of a cooling source for the second cooling device and adapted to participate in activating the second cooling device based on said availability of the cooling source.

2. An arrangement according to claim 1, wherein the second the cooling source is exterior air from outdoors.

3. An arrangement according to claim 2, wherein the controller is coupled to a temperature sensor for measuring the temperature of the exterior air, the control function being adapted to participate in activating the first cooling device when the temperature inside the refrigeration device is greater than a first pre-determined temperature and when the temperature of the exterior air is above a second pre-determined temperature and adapted to participate in activating the second cooling device when the temperature inside the refrigeration device is greater than the first pre-determined temperature and when the temperature of the exterior air is below a third pre-determined temperature, the second pre-determined temperature being less than or equal to the first pre-determined temperature and the third pre-determined temperature being less than or equal to the second pre-determined temperature.

4. An arrangement according to claim 1, wherein the first cooling device comprises an evaporator, the arrangement comprising a compressor and condenser arrangement coupled to the evaporator, and the control function being adapted to participate in activating the first cooling device by activating the compressor and condenser arrangement.

5. A refrigeration device comprising the arrangement of claim 1, the refrigeration device further comprising a body having an interior, the first cooling device and the second cooling device being adapted to cool the interior of the body.

6. A refrigeration device according to claim 5, wherein the second the cooling source is exterior air from outdoors.

7. A refrigeration device according to claim 5, wherein the controller comprises a temperature sensor for measuring the temperature of the exterior air, the control function being adapted to participate in activating the first cooling device when the temperature inside the refrigeration device is greater than a first pre-determined temperature and when the temperature of the exterior air is above a second pre-determined temperature and adapted to participate in activating the second cooling device when the temperature inside the refrigeration device is greater than the first pre-determined temperature and when the temperature of the exterior air is below a third pre-determined temperature, the second pre-determined temperature being less than or equal to the first pre-determined temperature and the third pre-determined temperature being less than or equal to the second pre-determined temperature.

8. A refrigeration device comprising: a body having an interior; and a cooling device adapted to cool the interior of the body using an exterior air from outdoor as a cooling source.

9. A refrigeration device according to claim 8 comprising a controller coupled to a temperature sensor for measuring the temperature of the exterior air, the controller having a control function adapted to activate the cooling device only if the temperature of the exterior air is below a pre-determined temperature.

10. A refrigeration device according to claim 9 comprising an other cooling device adapted to cool the interior of the body, the control function being adapted to participate in activating the other cooling device only if the temperature of the exterior air is above an other pre-determined temperature, the other pre-determined temperature being less than or equal to the pre-determined temperature.

11. A refrigeration device according to claim 10, wherein the cooling device comprises at least one of a fan and a blower for directing the exterior air into the refrigeration device.

12. A refrigeration device according to claim 10, wherein the cooling device comprises a coil adapted to receive the exterior air for circulation through the coil.

13. A refrigeration device according to claim 10, wherein the cooling device comprises at least one fan or blower for circulating air in the interior of the body across the coil.

14. A refrigeration device according to claim 8 comprising a filter for filtering the exterior air.

15. A refrigeration device according to claim 10 comprising a compressor and condenser arrangement, the other cooling device comprising an evaporator coupled to the compressor and condenser arrangement, and the control function being adapted to participate in activating the other cooling device by activating the compressor and condenser arrangement.

16. A refrigeration device according to claim 8, wherein the refrigeration device is one of a refrigerator, a freezer, a cooler, a walk-in cooler, a walk-in freezer, a home appliance refrigerator, a home appliance freezer, a home appliance refrigerator and freezer, an open refrigeration device, a closed refrigeration device, an open freezer counter, an open cooler counter, a tractor trailer freezer, and a tractor trailer cooler.

17. A refrigeration device according to claim 8 comprising an exhaust unit for directing air in the refrigeration device out of the refrigeration device.

18. Use of a controller in activating a first cooling device of a refrigeration device on the basis of availability of a cooling source for the first cooling device and in activating a second cooling device of the refrigeration device on the basis of said availability of the cooling source for the first cooling device.

19. The use according to claim 18 wherein the cooling source is cold exterior air from outdoor.

20. The use according to claim 18, wherein the controller is a single pole double throw temperature control.

Description:

RELATED APPLICATION

This Application claims the benefit of U.S. Provisional Application No. 60/576,136 filed Jun. 3, 2004.

FIELD OF THE INVENTION

The invention relates to a refrigeration device, system, and use of a controller thereof.

BACKGROUND OF THE INVENTION

Refrigeration devices such as refrigerators, freezers, coolers, walk-in coolers, and walk-in freezers typically make use of compressors for cooling. The use of compressors for purposes of cooling is costly. This is of particular importance for walk-in devices in which people can walk in and out. A business such as a grocery store, beer store, warehouses, and shipping facilities, or transport vehicles for example might have several of these devices and other refrigeration devices each requiring a compressor. The costs associated with operating the compressors form a significant contribution to operating costs of a business especially when the compressors operate 12 month per year. Furthermore, these compressors are expensive and have a limited life span. The use of compressors year round results in maintenance costs and a reduced life span of the compressors. Furthermore, when cooled using a compressor the air within a refrigeration device is cooled; however, there is no exchange with fresh air resulting in stale air within the refrigeration device.

SUMMARY OF THE INVENTION

A refrigeration device has a body having an interior. A first cooling device is adapted to cool the interior of the body. A second cooling device is also adapted to cool the interior of the body using a cooling source. A temperature controller participates in activating the first cooling device based on availability of the cooling source for the second cooling device and participates in activating the second cooling device based on the availability of the cooling source.

The first cooling device might be for example an evaporator operating in combination with a compressor and condenser arrangement and the cooling source for the second cooling device might be cold exterior air from outdoors, in which case the exterior air is used to cool the interior of the refrigeration device. The use of the cold exterior air for cooling the interior of the refrigeration device provides economical cooling without having to operate the compressor, which requires extensive energy consumption. Furthermore, the cooling with the cold exterior air during cold periods of time reduces the operating time of the compressor and condenser arrangement and lengthens the life span of the arrangement. In some embodiments, the exterior air being used to cool the refrigeration device provides a source of fresh air preventing the air within the refrigeration device from becoming stale. In some embodiments, the refrigeration device is cooled using only cold exterior air and in some of these embodiments the refrigeration device has only one cooling device corresponding to the above second cooling device.

In accordance with a broad aspect, the invention provides an arrangement for a refrigeration device. The arrangement has a first cooling device, a second cooling device, and a controller having a control function adapted to participate in activating the first cooling device based on availability of a cooling source for the second cooling device and adapted to participate in activating the second cooling device based on said availability of the cooling source.

In some embodiments, the second the cooling source is exterior air from outdoors.

In some embodiments, the controller is coupled to a temperature sensor for measuring the temperature of the exterior air. The control function is adapted to participate in activating the first cooling device when the temperature inside the refrigeration device is greater than a first pre-determined temperature and when the temperature of the exterior air is above a second pre-determined temperature. The control function is also adapted to participate in activating the second cooling device when the temperature inside the refrigeration device is greater than the first pre-determined temperature and when the temperature of the exterior air is below a third pre-determined temperature. The second pre-determined temperature is less than or equal to the first pre-determined temperature and the third pre-determined temperature is less than or equal to the second pre-determined temperature.

In some embodiments, the first cooling device has an evaporator and the arrangement has a compressor and condenser arrangement coupled to the evaporator. The control function is adapted to participate in activating the first cooling device by activating the compressor and condenser arrangement.

In accordance with another broad aspect, the invention provides a refrigeration device having the above arrangement and a body having an interior. The first cooling device and the second cooling device are adapted to cool the interior of the body.

In accordance with another broad aspect, the invention provides a refrigeration device having a body having an interior, and a cooling device adapted to cool the interior of the body using an exterior air from outdoor as a cooling source.

In some embodiments, the refrigeration device has a controller coupled to a temperature sensor for measuring the temperature of the exterior air, the controller having a control function adapted to activate the cooling device only if the temperature of the exterior air is below a pre-determined temperature.

In some embodiments, the refrigeration device has another cooling device adapted to cool the interior of the body. The control function is adapted to participate in activating the other cooling device only if the temperature of the exterior air is above another pre-determined temperature, the other pre-determined temperature being less than or equal to the pre-determined temperature.

In some embodiments, the cooling device has at least one of a fan and a blower for directing the exterior air into the refrigeration device.

In some embodiments, the cooling device has a coil adapted to receive the exterior air for circulation through the coil.

In some embodiments, the cooling device has at least one fan or blower for circulating air in the interior of the body across the coil.

In some embodiments, the refrigeration device has a filter for filtering the exterior air.

In some embodiments, the refrigeration device has a compressor and condenser arrangement and the other cooling device has an evaporator coupled to the compressor and condenser arrangement. The control function is adapted to participate in activating the other cooling device by activating the compressor and condenser arrangement.

In some embodiments, the refrigeration device is one of a refrigerator, a freezer, a cooler, a walk-in cooler, a walk-in freezer, a home appliance refrigerator, a home appliance freezer, a home appliance refrigerator and freezer, an open refrigeration device, a closed refrigeration device, an open freezer counter, an open cooler counter, a tractor trailer freezer, and a tractor trailer cooler.

In some embodiments, the refrigeration device has an exhaust unit for directing air in the refrigeration device out of the refrigeration device.

In accordance with another embodiment, the invention provides the use of a controller in activating a first cooling device of a refrigeration device on the basis of availability of a cooling source for the first cooling device and in activating a second cooling device of the refrigeration device on the basis of said availability of the cooling source for the first cooling device.

In some embodiments, the controller is a single pole double throw temperature control.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention will now be described with reference to the attached drawings in which:

FIG. 1 is a block diagram of a conventional refrigeration device in a building;

FIG. 2 is a block diagram of a refrigeration device in a building, in accordance with an embodiment of the invention;

FIG. 3A is a flow chart of a method of controlling the temperature in the refrigeration device of FIG. 2;

FIG. 3B is a method of determining which control device of FIG. 2 is to operate in the method of FIG. 3A;

FIG. 4A is a side view of a cooling device, in accordance with another embodiment of the invention; and

FIG. 4B is a top view of the cooling device of FIG. 4A.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Refrigeration devices are used to store goods that require storage at a specific temperature. Compressors are typically used in cooling the air in the refrigeration device to the specific temperature.

Referring to FIG. 1, shown is a block diagram of a conventional refrigeration device 10 in a building 20. The refrigeration device 10 has a cooling device 30 that is powered by a compressor and condenser arrangement 40. The compressor and condenser arrangement 40 has a temperature controller 50 and a feed line 60, which provides to the cooling device 30 a liquid that has been condensed from a compressed gas. The cooling device 30 is an evaporator equipped with an expansion valve and a coil (not shown). A return line 65 returns the liquid from feed line 60 in the form of a gas to the compressor and condenser arrangement 40.

The compressor and condenser arrangement 40 provides a cooling source to the cooling device 30 by compressing a gas and condensing the gas into a liquid that is fed through feed line 60. The liquid from the compressor and condenser arrangement 40 propagates in feed line 60 to the cooling device 30 where it is evaporated and cooled allowing the cooling device 30 to cool the interior of the refrigeration device 10. The gas from the evaporated liquid returns to the compressor and condenser arrangement 40 by way of return line 65. A temperature T1 inside the refrigeration device 10 is to be kept at a predetermined temperature in the range of T′1±ΔT where T′1 might be approximately 2° C. for a cooler or refrigerator, for example, and approximately −15° C. for a freezer, for example. ΔT might be approximately 2° C. for example. The temperature controller 50 activates the compressor and condenser arrangement 40 when the temperature T1 inside the refrigeration device 10 reaches T′1+ΔT and stops the compressor and condenser arrangement 40 when the temperature inside the refrigeration device 10 reaches T′1−ΔT.

At certain times (in winter for example), a temperature T2 outside a building is within or below the range T′1±ΔT. In some embodiments of the invention, this cold exterior air is used as a source for cooling the interior of a refrigeration device instead of using a compressor and condenser arrangement.

Referring to FIG. 2, shown is a block diagram of a refrigeration device 210 in a building 220, in accordance with an embodiment of the invention. In FIG. 2, the refrigeration device 210 has cooling device 30, another cooling device 230, a controller 280, and an exhaust unit 260. A compressor and condenser arrangement 240 provides a first cooling source for the cooling device 30. The cooling device 230 is in communication with the exterior of the building 220 by way of a passage 245 that provides access to cold exterior air. The passage 245 has a filter 255. The cold exterior air provides a second cooling source for the cooling device 230. The controller 280 has a control function (CF) 291 connected to the temperature controller 250 and to a temperature controller (TC) 290. A user interface (UI) 292 is connected to the control function 291. A temperature sensor 294 is connected to the controller 280. The exhaust unit 260 is also in communication with the exterior of the building 220 by way of a passage 270.

In some embodiments of the invention there is no exhaust unit 260; however, the use of the exhaust unit 260 allows increased exchange of stale air with fresh air. The exhaust unit 260 is for example a fan or blower and is preferably located at a highest point in the refrigeration device 210, for example at a ceiling 296 in the refrigeration device 210 where the warmer rises. The exhaust unit 260 is coupled to the cooling device 230 and operates when the cooling device 230 is activated. In other embodiments, the exhaust unit 260 is not coupled to the cooling device 230 operates independently of the cooling device 230 using a timer for example. In some embodiments, the exhaust unit 260 opens and closes access to the passage 270 depending on when the cooling 30 and/or the cooling device 230 operates. In such embodiments, the exhaust unit 260 may or may not have a fan or blower.

The refrigeration device 210 might be for example a refrigerator, a freezer, a cooler, a walk-in cooler, or a walk-in freezer. In some embodiments of the invention, the refrigeration device 210 is a home appliance refrigerator or freezer and the compressor and condenser arrangement 240 forms an integral part of the refrigeration device 210. Furthermore, the refrigeration device 210 might be an open device such as an open freezer or cooler counter for a store, for example. Alternatively, the refrigeration device 210 might be a closed device, such as a walk-in cooler or a walk-in freezer having doors, for example. In FIG. 2 the refrigeration device 210 is implemented in building 220; however, it is to be clearly understood that the embodiments of the invention are not limited to implementations in a building. For example, in some embodiments of the invention the refrigeration device 210 is a freezer or cooler for a tractor trailer used for transportation.

The cooling device 230 may be for example a fan or a blower for blowing cold exterior air into the refrigeration device 210. This allows the cold exterior air to enter the refrigeration device 210 to cool the interior of the refrigerator device 210 and to prevent the air in the refrigeration device from becoming stale. The exhaust unit 260 also aids in the exchange of air. The filter 255 is used to filter the cold exterior air before its enters the refrigeration device 210. However, it is to be clearly understood that in other embodiments of the invention, there is no filter 255. Furthermore, in some embodiments of the invention the cooling device 230 has a coil through which the cold exterior air circulates and one or more fans and/or blowers for blowing air across the coil to effectively cool the air in the refrigeration device 210. Such a cooling device is illustrated in FIGS. 4A and 4B. In particular, in FIGS. 4A and 4B a cooling device 460 has a coil 410 for receiving exterior air 420 and circulating the exterior air 420 through the cooling device 460 with the use of a fan or blower 450. Cooling fins 430 are used to conduct heat from the interior of the refrigeration device into the coil 410. A fan or blower 440 blows air in the interior of the refrigeration device across the cooling device 460 to cool the air. In some embodiments, the cooling unit 30 is an evaporator and has a coil and cooling fins. In some of these embodiments the cooling unit 230 forms part of the cooling unit with the coil 410 running through the cooling fins of the cooling unit 30.

It is clear that the cooling device 230 can be of different types. In yet other embodiments of the invention, the cooling device 230 has a pipe running in the interior of the refrigeration unit 210. The pipe is perforated to allow the exterior air in the pipe to escape through the perforations. This provides a plurality of points of entry of the cool exterior air into the refrigeration device 210 even cooling throughout the interior of the refrigeration unit 210. In some embodiments, there are two or more cooling units 230 to cool the interior of a large refrigeration unit, for example. In some embodiments, two or more of the cooling units are controlled by a common controller. In some embodiments of the invention, the cooling unit 230 is outside the building 220.

In the embodiment of FIG. 2, the control function 291 participates in activating the cooling device 30 when cold exterior air from outdoor for the cooling device 230 is not available and participates in activating the cooling device 230 when the cold exterior air for the cooling device 230 is available. The user interface 292 allows a user to input a pre-determined temperature T3 for which if the outside temperature T2 is below T3 the controller 280 is used to activate the cooling device 230 and if the outside temperature T2 is above T3 the controller 280 participates in activating the cooling device 30 by activating the compressor and condenser arrangement 240. The temperature T3 is set below T′1+ΔT and preferably below T′1−ΔT.

The temperature controller 250 of the compressor and condenser arrangement 240 operates to activate the compressor and condenser arrangement 240 under control of the controller 280 to keep the temperature T1 inside the refrigeration device 210 within the range T′1±ΔT when the temperature T2 outside the building 220 is above T3. The temperature controller 290 of the cooling device 230 operates to activate the cooling device 230 under control of the controller 280 to keep the temperature T1 inside the refrigeration device 210 within the range T′1±ΔT when the temperature T2 outside the building 220 is below T3.

In the embodiment of FIG. 2, the functionality of both the control function 291 and the user interface 292 are implemented separately from the compressor and condenser arrangement 240 and the cooling device 230; however, in some embodiments of the invention the functionality of the control function 291 is implemented as part of the compressor and condenser arrangement 240 or its temperature controller 250, or as part of the cooling device 230. Similarly, in some embodiments of the invention the functionality of the user interface 292 is implemented as part of the compressor and condenser arrangement 240 or its temperature controller 250, or as part of the cooling device 230. Alternatively, in some embodiments of the invention, there is no user interface 292 and the temperature T3 is set by the control function 291 on the basis of T′1 and ΔT, which might be set at the temperature controller 250, for example. In some embodiments of the invention, the functionality of the temperature controller 290 is implemented as part of the controller 280.

In the embodiment of FIG. 2, the cooling source for the cooling device 230 is outdoor air; however, in some other embodiments of the invention the cooling source is any suitable source of cold air. Furthermore, the use of the cooling device 230 allows for savings in energy consumption during cold days, weeks or months. Embodiments of the invention are not limited to the use of cold air at times of availability of cold air. For example, in some embodiments the compressor and condenser arrangement 240 is powered using electricity and the cooling device 230 is a heat pump for example operated using natural gas or propane. In such embodiments, the use of the cooling device 30 and the cooling device 230 might be controlled by the controller 280 under control of availability of electricity and natural gas or propane. Furthermore, availability might also be determined on the basis of cost of electricity versus cost of natural gas or propane.

In some embodiments of the invention, the cooling device 30 is a heat pump and the compressor and condenser arrangement 240 forms an integral part of the cooling device 30. Furthermore, in some embodiments of the invention there is no compressor and condenser arrangement 240 and no cooling device 30. Such refrigeration devices might be used for example in areas or conditions where there is a continuous source of cold air.

Referring to FIG. 3A, shown is a flow chart of a method of controlling the temperature in the refrigeration device 210 of FIG. 2. At step 310, a determination of which cooling device 30, 230 that is to operate is made. At step 320, the cooling device that is not to operate is stopped if it is running. At step 330, the cooling device that is to operate maintains the interior of the refrigeration device 210 within the temperature range T′1±ΔT.

It is to be made clear that embodiments of the invention are not limited to the method of FIG. 3A. For example, in some embodiments at step 320 the cooling device that is not to operate is allowed to continue to operate until the temperature inside the refrigeration device 210 reaches T′1ΔT.

Referring to FIG. 3B, shown is a method of determining which control device 30, 230 is to operate in the method of FIG. 3A. With reference to FIG. 2, the control function 291 has a default state and a non-default state. In the default state the control function 291 provides instructions to the compressor and condenser arrangement 40 for participating in activating the cooling device 30. In the non-default state the control function 291 provides instructions to the cooling device 230 for activating the cooling device 230. At step 340, the control function 291 is set to the default state. If the control function 291 is in the default state (step 350) and the temperature T2<T3−ΔT3 (step 360), then the state is changed to the non-default state (step 370) before going back to step 350, for providing instructions to the cooling device 230 to activate the cooling device 230; otherwise, the state remains in the default state. On the other hand, at step 350, if the control function is not in the default state and the temperature T2>T3+ΔT3 (step 380), then the state is changed to the default state (step 390) before going back to step 350, for providing instructions for activating the cooling device 30; otherwise the setting remains in the non-default state.

The method of FIG. 3B allows the cooling device 30 to be activated when T2>T3+ΔT3 and continue to operate as long as the temperature T2 does not drop below T3−ΔT3. The method also allows the cooling device 230 to be activated when T2<T3−ΔT3 and continue to run as long as the temperature T2 is below T3+ΔT3. As discussed above, it is clear, however, that the cooling devices 30, 230 also operate as a function of the temperature inside the refrigeration device 210.

ΔT3 might be 1° C. for example; however, it is to be clearly understood that other temperatures can be used. More generally, T3−ΔT3≦T3+ΔT3≦T′1+ΔT.

A change of state from the default state to the non-default state when the temperature T2<T3−ΔT3 and a change of state from the non-default state to the default state when the temperature T2<T3−ΔT3 prevents rapid flip-flop between the default and non-default states due variations in the outside temperature T2. It to be clearly understood that embodiments of the invention are not limited to the method of FIG. 3B for preventing rapid flip-flop between the default and non-default states. For example, in some embodiments of the invention rapid flip-flop is avoided by making a determination of which cooling device is to be activated at pre-determined time intervals. Such intervals might be 30 minutes for example. However, longer or shorter intervals may be used.

In some implementations, the methods of FIGS. 3A and 3B are implemented by having the controller 280 operate to cut and turn on power to the compressor and condenser arrangement 40 and the cooling device 230 depending on whether T2<T3−ΔT3 and T2>T3+ΔT3, respectively. This might be implemented using a single pole double throw temperature control for example.

It is to be clearly understood that the invention is not limited to operating the compressor and condenser arrangement 240 and the cooling device 230 as described with reference to FIGS. 3A and 3B. For example, the methods described above involve only one of the cooling devices 30, 230 operating at any instant in time; however, in other embodiments of the invention both cooling devices 30, 230 are activated when there is cold exterior air available and only cooling device 30 is activated when there is no cold exterior air available. In some of these embodiments, the controller 280 operates to activate only the cooling device 230.

Referring back to FIG. 2, embodiments of the invention are not limited to the use of a single pole double throw temperature control in implementing the above functionality for controlling the compressor and condenser arrangement 240 and the cooling device 230. In other embodiments of the invention, the functionality or any part thereof can be implemented using any suitable software, firmware, or hardware, or any combination thereof.

As discussed above, in some embodiments of the invention a home appliance refrigerator or freezer has the compressor and condenser arrangement 240 forming an integral part of the refrigeration device 210. In some embodiments of the invention, a refrigerator has a refrigerator compartment and a freezer compartment, and a cooling device such as cooling device 30 is in communication with the freezer compartment. In some of these embodiments the refrigerator compartment has a cooling device, such as cooling device 230 for example, adapted to be activated using a controller when the exterior air is cool enough to cool the interior of the refrigerator compartment. In some embodiments, the freezer compartment has a cooling device, such as cooling device 230 for example, adapted to be activated using a controller when the exterior air is cool enough to cool the interior of the freezer compartment. In some embodiments, both the refrigerator and freezer compartments have cooling devices adapted to cool respective interiors of the refrigerator and freezer compartments using exterior air.

Numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practised otherwise than as specifically described herein.