The present invention relates to air cooling equipment, dehumidifiers and auxiliary water pre-heaters, and more particularly to a room air cooler/dehumidifier and water preheater to be used in conjunction with a tap water supply in a hot and humid environment, such as a commercial kitchen.
Commercial kitchens, such as those found in restaurants, hospitals, dorms, etc., are uncomfortable year round due to excessive heat and moisture which occur from preparing the food. In order to cool or dehumidify the kitchen with a conventional air conditioner system, this results in a large expense and excessive energy consumption. Many such systems cannot be operated in the winter in that they must be drained to avoid freezing of various fluids used in the system.
My prior U.S. Pat. No. 4,759,195 discloses a dehumidifier for use in an industrial or commercial building in conjunction with an air conditioning system which utilizes the natural coolness of tap water to condense water vapor from the air upstream of the evaporator coils of an air conditioner.
That patent teaches to place a dehumidifying/pre-heating coil within the duct work comprising the air conditioning system. Such an arrangement generally would be useful only when the air conditioning system is operating, and will provide cooler/dryer air only in those areas serviced by the air conditioning system.
My later U.S. Pat. No. 5,878,588 discloses a dehumidifier/cooling apparatus for use in a room having an elevated temperature and/or humidity which utilizes the natural coolness of tap water to condense water vapor from the air or merely cool the air. The tap water line is diverted into a heat exchanger upstream of a hot water heater to dehumidify and/or cool the air in the room the air and remove the latent heat given off during condensation to cool and/or dehumidify the room air and to pre-heat the water entering the hot water heater. The system taught in that patent utilized an electrically powered fan to circulate air over the condenser coils. It has been determined that even with the use of a low energy fan, the cost savings in terms of reduced energy cost for heating the hot water used in the kitchen was nearly outweighed by the increased energy cost for operating the fan. Thus, the system was not widely adopted because the additional cost of the system was not recovered by energy cost savings in running the system.
The present invention utilizes the same, substantially untapped, yet readily available and virtually free energy source to do the work of dehumidifying and cooling the air in a hot and/or humid room. This untapped energy source is the nearly constantly flowing water supply line to an industrial or commercial building which has the capacity to absorb a large amount of heat from the room air, perhaps sufficient to reduce the temperature below the dew point and to thereby condense the moisture from the air. In any event, the room air will be cooled and the tap water will be preheated before being directed to a standard hot water heater for further heating. Because this water is pre-heated, the cost of operating the hot water heater will be reduced. It is preferred to direct only that water leading to the hot water heater through the dehumidifying/cooling apparatus, thereby to maximize the heat gain to the water to be heated. This will also avoid heating other water where heating is not desired.
The improvement and advantage that the present invention provides is a removal of the energy cost associated with creating a flow of air through the heat exchanger condenser coils. This is achieved by using a water flow powered air moving impeller or fan which results in a minimal pressure drop in the building water line.
Since large commercial kitchens have a relatively constant usage of tap water, the water in the incoming water line will substantially be constantly moving, thus providing a continuous source of relatively cold water to act as a power source for the air moving device, as well as a refrigerant to provide the dehumidification and cooling for the room air. After flowing through a hydro-turbine, the continuously moving water, in the heat exchanger condenser coils, will absorb the heat given off by the water vapor as it condenses, thus preventing the air leaving the dehumidifier/cooling coil from remaining at an elevated temperature. The tap water flowing through the dehumidifier/cooling coil will simultaneously be pre-heated for use in the hot water line leading to the hot water heater.
It is contemplated by the present invention that the incoming water line can be selectively diverted through a finned tube heat exchanger which is placed in the room to be cooled and dehumidified. A water powered fan draws room air over the finned tube heat exchanger. The tap water may also be selectively caused to bypass the heat exchanger coil if the humidity of the air is low or if the temperature of the air in the room is already at a comfortable level.
A drain is provided for directing the condensed water vapor to an appropriate discharge point and a meter can be utilized in the drain to measure amount of water collected and thus the effectiveness of the tap water dehumidifying apparatus.
In
The dehumidifying/cooling apparatus 12 which incorporates the principles of the present invention, comprises a heat exchanger 17 illustrated in
The inlet pipe 22 is connected by means of a T-junction 26 and the first connection 60 of the first header pipe 20. The second valve 30 is positioned between the T-junction 26 and the discharge piping 24. The second connection 62 of the header pipe 23 is connected to a third valve 34 which then connects by way of piping 36 to a T-junction 38, one leg of which is connected to the discharge piping 24 and the other leg of which is connected to the second valve 30.
The inlet pipe 22 is connected to the water supply line 40 or water main through which tap water for the room is supplied. The inlet pipe 22 is connected to a hydro-turbine 82 which is positioned between the water supply line 40 and the T-junction 26. As shown in
Since the water flowing through the hydro-turbine 82 is to available for human consumption, it is preferred that the hydro-turbine be fabricated without the use of lead, such as in the soldering or brazing materials used to connect the hydro-turbine to the inlet pipe, or within the casing 86 of the hydro-turbine itself. The turbine wheel 84 preferably is fabricated from plastic or other materials suitable for potable water systems, including metals such as copper or stainless steel.
The water flowing through the inlet pipe 22, and through the casing 86 of the hydro-turbine 82, will cause the blade or impeller 96 to rotate with sufficient speed so as to draw air into the open end 16 of the air intake conduit 14 and through the heat exchanger 17. After passing the air moving device 19, the now cooled, and perhaps dehumidified air, will circulate in the room. Air movement direction fins 98 may be provided downstream of the air moving device 19 to allow the user to direct the flow of air from the air moving device in a desired direction.
A bypass pipe 42 (
The discharge pipe 24 is connected to the makeup water inlet 25 of the hot water heater 44, thereby preheating the makeup water feeding into the hot water heater 44. An outlet pipe 46 from the hot water heater 44 is provided to supply hot water to the hot water outlets in the room or elsewhere.
When the dehumidifier/cooling apparatus 12 is in operation, valves 28 and 34 are open while valve 30 is closed. This causes all of the water flowing in through inlet piping 22, downstream of the cold water bypass pipe 42, to flow through the first header pipe, the coils 18 and then out through the second header pipe to the discharge piping 24. When it is desired to take the coils 18 out of operation, valves 28 and 34 are closed while valve 30 is opened. This then causes the water to flow in through inlet piping 22 to bypass the coils 18 by flowing through valve 30 and then out through discharging piping 24. Intermediate flows of less than all of the inflowing tap water can be effected by partially opening both valve 28 and valve 34.
To avoid an unacceptable pressure drop in the tap water line feeding the hot water heater 44, the header pipes 20, 23 are oversized, preferably with an O.D. of about 2 inches. This 2 inch dimension assumes that the inlet piping 22 and discharge piping 24 and intermediate piping 36 are of a smaller diameter such as 1½ inches. This also assumes that the coils 18 are of a much smaller diameter such as ½ inch. As will be evident to those in the art, the header pipes may be of a size other than 2 inches as long as the inlet and discharge piping 22 and 24 and the coil tubes 18 are correspondingly sized according to the requirements of the particular dehumidifying/cooling system 12. Most heat exchangers are not concerned with pressure loss since the water (or other fluid) flowing therethrough is merely disposed of and not used. In this application, the pressure is of concern and must be maintained because hot water is being used downstream of the system. Also, since the water flowing through the heat exchanger is to available for human consumption, it is preferred that the heat exchanger be fabricated without the use of lead, such as in the soldering or brazing materials. All of the components of the dehumidifying/cooling apparatus 12 which come in contact with the water flowing though the water inlet pipe 22, which includes the associated plumbing and valves, should be fabricated from and installed with materials approved for use in potable water systems.
In order to effect a dehumidification of the air by flowing tap water through the coils 18, the water has to be below the dew point of the air. As an example, the tap water in the Chicago area during the summer of 1985 ranged from 51 degrees F. to 71 degrees F. with an average of 61 degrees F. An average temperature of 61 degrees F. would be below the dew point temperature of air 70 degrees F. or above, with a relative humidity of 42% or above. As the air temperature rises, the relative humidity percentage at a specific dew point temperature would drop. That is, at an ambient air temperature of 85 degrees F., the dew point temperature of 61 degrees F. corresponds to a relative humidity of approximately 22%. In an environment of a kitchen or similar room having sources of heat and humidity, these conditions are often met. Thus, the tap water would be effective to condense moisture out of the air as the air is circulated through the dehumidifying/cooling device 12. Further, even if dehumidifying does not occur, cooling of the air in the room will occur since the temperature of tap water is generally below the room temperature in a kitchen or similar environment, which may be, for example, 95 degrees F.
Since the air moving device 19 is powered by the movement of water through the inlet pipe 22, the operation of the air moving device does not need to be separately controlled, such as with the use of a thermostat, as in the prior arrangement as discussed in U.S. Pat. No. 5,878,588. As such, air movement in the room effected by the air moving device 19 will be substantially continuous, so long as the movement of water through the inlet pipe 22 is substantially continuous.
Positioned below the coils 18 is a condensate collection trough 50 which serves to direct the condensed water vapor to a drain pipe 52. This trough 50 may be incorporated into the heat exchanger housing 64, the system enclosure 13, or both. A flow meter 54 can be placed in the drain pipe 52 to provide a visual indication of the amount of water vapor being extracted from the air as a means of determining the energy savings of the apparatus.
Thus, a substantially free energy cost arrangement, which no longer requires a separately powered fan, is provided to absorb the latent heat of water vapor from the air and to thereby dehumidify the air and/or cool the air. This previously unused, but readily available source of energy can effect a substantial improvement in the comfort in the room without any energy cost. Further, an energy cost of operating the hot water heater will also be reduced.
It will be appreciated that automatic controls can be applied to the valves to selectively open or close the valves depending upon the temperature and humidity conditions of the air as well as the incoming water in order to automatically cause the water to flow through the dehumidifying apparatus when the water temperature is below the dew point temperature of the ambient air or when the ambient air is above a certain comfort level.
Alternatively, as shown in
As is apparent from the foregoing specification, the invention is susceptible of being embodied with various alterations and modifications which may differ particularly from those that have been described in the preceding specification and description. It should be understood that I wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of my contribution to the art.