Fan with cooler

Abstract

A fan with an integrated cooler is disclosed. Unlike conventional air-conditioners, the device is compact and lightweight, and can be used both indoors and outdoors without the need to enclose or otherwise control the user environment from thermal considerations.

Claims

1. An air cooling system for circulating air cooled to a temperature below ambient in a space open to the external environment, comprising a fan and a refrigeration unit utilizing a vapor compression cooling cycle, said fan comprising one of a ceiling fan, a personal fan, a pedestal fan, a wall-mounted fan, a tower fan, a floor fan, a box fan, a window fan, a drum fan, a blower fan or an oscillating fan, said refrigeration unit being integrated with said fan utilizing a support structure and comprising a compressor, a connecting tubing, a heat absorption evaporator, a heat dissipation condenser and a secondary heat dissipation fan, wherein said fan, said compressor, said connecting tubing, said heat absorption evaporator, said heat dissipation condenser and said secondary heat dissipation fan are all positioned in said space, said heat absorption evaporator being positioned adjacent to said fan such that air circulated by said fan passes over said heat absorption evaporator, said heat dissipation condenser being positioned adjacent to said secondary heat dissipation fan such that air circulated by said secondary heat dissipation fan is forced to pass over said heat dissipation condenser, wherein said heat absorption evaporator and saki heat dissipation condenser both exchange heat with air from said space, with said secondary heat dissipation fan being positioned such that its exhaust air is directed away from air incoming to said fan, and with said refrigeration unit having a cooling capacity not greater than 300 W when the temperature difference is not less than 20 K or greater than 30 K between said heat absorption evaporator and sad heat dissipation condenser.

2. The air cooling system of claim 1, wherein said heat absorption evaporator is configured to function as a finger-guard.

3. The air cooling system of claim 1, wherein said heat absorption evaporator has at least one heat transfer enhancement feature.

4. The air cooling system of claim 1, wherein said heat dissipation condenser and said secondary heat dissipation fan are an integrated radiator-fan assembly.

5. The air cooling system of claim 1, wherein said refrigeration unit comprises flexible tubing.

6. The air cooling system of claim 1, wherein said refrigeration unit can function as a heat-pump with said heat absorption evaporator functioning as the heat dissipation/condensing section and said heat dissipation condenser functioning as the heat absorption/evaporating section.

7. An air cooling system for circulating air cooled to a temperature below ambient in a space open to the external environment, comprising a fan and a refrigeration unit utilizing a vapor compression cooling cycle, said fan comprising one of a ceiling fan, a personal fan, a pedestal fan, a wall-mounted fan, a tower fan, a floor fan, a box fan, a window fan, a drum fan, a blower fan or an oscillating fan, said refrigeration unit being integrated with said fan utilizing a support structure and comprising a compressor, a connecting tubing, a heat absorption evaporator, a heat dissipation condenser and a secondary heat dissipation fan, wherein said fan, said compressor, said connecting tubing, said heat absorption evaporator, said heat dissipation condenser and said secondary heat dissipation fan are all positioned in said space, said heat absorption evaporator being positioned adjacent to said fan such that air circulated by said fan passes over said heat absorption evaporator, said heat dissipation condenser being positioned adjacent to said secondary heat dissipation fan such that air circulated by said secondary heat dissipation fan is forced to pass over said heat dissipation condenser, wherein said heat absorption evaporator and said heat dissipation condenser both exchange heat with air from said space, with said secondary heat dissipation fan being positioned such that its exhaust air is directed away from air incoming to said fan, and with said refrigeration unit having a cooling capacity not less than 300 W and not greater than 600 W when the temperature difference is not less than 20 K or greater than 30 K between said heat absorption evaporator and said heat dissipation condenser.

8. The air cooling system of claim 7, wherein said heat absorption evaporator is configured to function as a finger-guard.

9. The air cooling system of claim 7, wherein said heat absorption evaporator has at least one heat transfer enhancement feature.

10. The air cooling system of claim 7, wherein said heat dissipation condenser and said secondary heat dissipation fan are an integrated radiator-fan assembly.

11. The air cooling system of claim 7, wherein said refrigeration unit comprises flexible tubing.

12. The air cooling system of claim 7, wherein said refrigeration unit can function as a heat-pump with said heat absorption evaporator functioning as the heat dissipation/condensing section and said heat dissipation condenser functioning as the heat absorption/evaporating section.

13. An air cooling system for circulating air cooled to a temperature below ambient in a space open to the external environment, comprising a fan and a refrigeration unit, said fan comprising one of a ceiling fan, a personal fan, a pedestal fan, a wall-mounted fan, a tower fan, a floor fan, a box fan, a window fan, a drum fan, a blower fan or an oscillating fan, said refrigeration unit being integrated with said fan utilizing a support structure and comprising a heat absorption means, a heat dissipation means and a secondary heat dissipation fan, wherein said fan, said support structure, said heat absorption means, said heat dissipation means and said secondary heat dissipation fan are all positioned in said space, said heat absorption means being positioned adjacent to said fan such that air circulated by said fan passes over said heat absorption means, said heat dissipation means being positioned adjacent to said secondary heat dissipation fan such that air circulated by said secondary heat dissipation fan is forced to pass over said heat dissipation means, wherein said heat absorption means and said heat dissipation means both exchange heat with air from said space, with said secondary heat dissipation fan being positioned such that its exhaust air is directed away from air incoming to said fan, and with said refrigeration unit having a cooling capacity not greater than 600 W.

14. The air cooling system of claim 13, wherein said refrigeration unit is one of a vapor compression refrigerator or a thermoelectric refrigerator.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic diagram of the preferred embodiment of the disclosed invention. The arrows in the FIGURE show the general direction of air-flow.

DETAILED DESCRIPTION

(2) FIG. 1 shows a preferred embodiment of the invention. It comprises the following:

(3) a) a ceiling-fan (100), i.e. a fan mounted on the ceiling (105) that is used to enhance air circulation locally in the region beneath it, and

(4) b) a miniature vapor compression refrigeration unit (200) with a cooling capacity of 100-300 W (at a temperature difference of the order of 20-30 C between its evaporator (210) and condenser (220)).

(5) The refrigeration unit is mounted above the fan blades (110) on the support structure/rod (120) of the fan assembly. Its evaporator (210) and condenser (220) are placed separately from each other and connected to the rest of the unit via tubing (225) which may be insulated. The heat absorption section of the refrigeration unit (its evaporator/cooling coil (210)) is positioned primarily below/adjacent to the fan blades (110) so that the air forced downwards by the fan (100) blows over it dissipating heat to the evaporator (210) in the process. The air circulated by the fan (100) to the region beneath it (i.e. the conditioned space) is now at a temperature that is below the ambient. Heat dissipation from the refrigeration unit occurs at the condenser (220) that is placed well above the fan. This is accomplished using a second dedicated fan (230) that forces air past the condenser (220) such that it flows in a direction away from the cooled region directly beneath the fan (100) (the arrows in FIG. 1 show general air-flow directions).

(6) It is important to note that the total heat dissipated from the refrigeration unit (200) is approximately equal to the sum of the heat absorbed by the evaporator (210) and the power used to drive the refrigeration system. In the preferred embodiment, this will be of the order of 130-450 W since the power required by the refrigeration unit will be of the order of 30-150 W (the overall coefficient of performance of a miniature vapor compression unit will be 2-3 for a temperature difference of 20-30 K). This quantity of heat (equivalent to that released by a few incandescent bulbs) can be readily removed from a room or an outdoor space to the wider environment without any additional equipment. As a result, the average temperature of operation and performance of the device will remain approximately constant regardless of whether it is used indoors or outdoors (as long as the wider environmental conditions do not change). Note that this will not be the case if the invention is used in a well-sealed, enclosed space with minimal air changes as is the situation with conventional air-conditioning systems, but this is a not an issue for the present application.

(7) In its simplest form, the evaporator (210) comprises one or more tubes with the heat transfer fluid (i.e. the refrigerant in the preferred embodiment). These may be configured such that the tube/coil assembly functions as a fan safety grill to minimize the possibility of accidental contact with the fan blades during operation. The heat dissipation condenser (220) and its dedicated fan (230) on the other hand can be a simple design comprising a quiet, compact, lightweight radiator-fan assembly that will maximize heat transfer with minimum power usage.

(8) The preferred embodiment described above can be modified to include a number of features that may provide other benefits such as improved performance and/or lower cost. Some of these include the following:

(9) a. For better performance, enhanced surfaces (e.g. fins (or decorative features that function as fins) to increase the heat transfer area and/or the degree of turbulence) are added to the evaporator tubes. This will increase the overall heat transfer for a given air flow rate and result in lower air temperatures that more closely approach that of the cooling coil. Further enhancements can include stationary blades and/or shrouds to improve the flow and heat transfer characteristics, but these may be incorporated in the most exceptional of cases.

(10) b. Other embodiments may use other types of household fans, e.g. personal fans, pedestal fans, wall-mounted fans, tower fans, floor fans, box fans, window fans, drum fans, blower fans, etc. As in the ceiling fan design, the evaporator/cooling coil can be placed primarily in front of the rotating blades and function as a safety grill/finger-guard. The heat dissipation radiator-fan assembly can be positioned facing the rear or an alternate direction that does not interfere with the main air-flow. The position of the refrigeration unit may also be changed, e.g. for a pedestal fan, it may be advantageous to place the refrigeration unit at the base of the pedestal to enhance stability and extend the cooling coils up to the face of the fan. However, it is important to note here that in the context of the claims, a fan assembly is defined as a type of appliance/household type fan (with multiple rotating blades or otherwise) that is generally used to circulate air in an outdoor or indoor living space to enhance human comfort (i.e. a small subset of the more general mechanical/aerospace engineering defined fan, which comprises a device for moving high volumes of a gas with low increase in its pressure (high and low are relative to other devices in the same family such as compressors)).

(11) c. Oscillating systems are also possible for the different configurations. In this case, the evaporator/cooling coil and/or the heat dissipation assembly must be connected to the refrigeration unit via flexible tubing/connectors to ensure proper functioning.

(12) d. For compact designs, i.e. where the distance between the evaporator/cooling coil and the secondary fan-radiator heat dissipation assembly is relatively small, it may be advantageous to place baffles next to the heat dissipation assembly to minimize any mixing between the incoming air to the fan(s) and the exhaust from the heat dissipating radiator. This will not be necessary in the preferred embodiment but may be useful in a wall-mount configuration.

(13) e. Another form of the preferred embodiment would use a hollow support and a hollow shaft motor for the fan. The cooling coil is then routed to the front of the fan through the hollow shaft, and the refrigeration unit and heat dissipation assembly can be placed within the hollow support (note that the support must have slots to allow for air flow). This makes the external appearance more pleasing and the air used for heat dissipation can be vented to the rear (and possibly into an attic space for a ceiling fan configuration.

(14) f. Though the preferred embodiment has a cooling capacity of 100-300 W, higher capacity (300-600 W) embodiments are viable for larger outdoor and semi-open warehouse type locations. Similarly, lower capacity (<100 W) may also be useful when limited cooling is required. Note that the overall configuration of such embodiments will be the same as in the preferred case. However, versions with cooling capacities greater than 600 W are not expected to be practical due to the larger size/weight of the refrigeration unit and the increased heat dissipation requirements (that will likely affect the cooled environment adversely).

(15) g. An alternative embodiment is possible using a thermoelectric cooling system instead of a vapor compression system. However, this will likely be viable only for low cooling capacity units due to the poor coefficient of performance of current thermoelectric modules/coolers (typically below 1) which results in significantly higher heat dissipation requirements as compared to vapor compression systems.

(16) h. A modular, but more complex embodiment may incorporate a secondary loop for the cooling coil and/or the heat dissipation coil. In this approach, the refrigeration unit is coupled to the secondary loop(s) via a heat exchanger(s). Note that this embodiment will require a pump(s) for the secondary loop and the overall system will be more complex and likely have increased size, weight and cost. As a result, this is not a preferred embodiment, except possibly when a thermoelectric refrigeration unit is used.

(17) i. An embodiment that has lower power consumption is possible by replacing the fan-radiator heat dissipation assembly by a passive radiator (that incorporates a thermo-siphon or a heat pipe, etc.). However, this embodiment may be viable only for units with lower cooling capacity and where a larger unit size will be acceptable. Such a unit may also be less versatile as orientation of a passive radiator is often critical (e.g. for thermo-siphons).

(18) j. In addition to its cooling focus, this invention can also incorporate a heating mode. This is accomplished by operating the refrigeration unit (200) such that it functions as a heat-pump, i.e. by redirecting the refrigerant flow within the unit so that the evaporator (210) functions as the heat dissipation (i.e. a condensing) section and the condenser (220) functions as the heat absorption (i.e. a evaporating) section. This variation of the invention will find additional use for fall/winter heating, though at a higher cost (due to the greater complexity of a dual refrigerator-heat pump configuration).

(19) k. A final version of the invention is a purely heat-pump version that is used only for local heating instead of cooling. As in the previous (cooling) cases, this embodiment will be practical only for limited heating loads. In this case, the main benefit is a reduced power consumption compared to the conventional approach for local heating applications (viz. electrical heating).

(20) Details of the refrigeration (and heat-pump) unit itself, the power source (e.g. systems may be powered by solar energy for outdoor units), the control system, etc. have not been described above since many variations are feasible based on prior art. Thus, while the invention has been described and disclosed in various terms or certain embodiments, the scope of the invention is not intended to be, nor should it be deemed to be limited thereby, and such other modifications or embodiments as may be suggested by the teachings herein are particularly reserved especially as they fall within the breadth and scope of the claims here appended.