Method and apparatus for cooling air and water

The present invention provides a method and apparatus for efficiently using various components as a system for cooling air. The apparatus uses the combination of an evaporative cooler with a water reservoir and a refrigerated air system with a water-cooled condenser. A pump or series of pumps are used to supply water to the evaporative cooler and to the water-cooled condenser from the water reservoir. A mechanism for controlling the hardness of supplied water may also be included. After the reservoir water has been supplied to the other components in the system, it is returned to the water reservoir. During cooler weather, the output air from the evaporative cooler is supplied to a series of ducts and is used to cool the interior of a structure such as a home. When the outside ambient temperature and/or humidity levels exceeds the capabilities of the evaporative cooler for cooling the interior of the structure to the desired temperature, the output air from the evaporative cooler is re-directed to the attic space of the structure and the refrigerated air from the refrigerated air system is used to cool the interior of the structure. By using the output air from the evaporative cooler to cool the attic space, the overall cooling load on the refrigerated air system is reduced. In addition, the use of the water from the reservoir to condense the refrigerant vapors will enable the system to achieve even greater efficiency.

BACKGROUND OF THE INVENTION 
1. Technical Field 
The present invention relates to changing the ambient air temperature 
inside a structure and, more specifically, to a cooling method and 
apparatus which provides a simple, yet very energy-efficient, means of 
cooling the interior of a structure and the water in a water storage unit. 
2. Background Art 
Human beings are known for their ability to adapt to their environment or, 
to adapt their environment to them. One example of this quality is the 
continued expansion of human populations into areas previously deemed 
inhospitable to human life. Desert communities such as Phoenix, Ariz. and 
Las Vegas. Nev. are two well-known and rapidly growing areas which support 
burgeoning populations. In order to survive in these hot, desert climates, 
most structures designed for human occupation are provided with one or 
more systems for cooling the air inside the structure. Some of the various 
types of systems used to cool the air inside a structure are typically 
rated by using a system which assigns a Seasonal Energy Efficiency Ratio 
(SEER) rating or number to the system. A higher SEER rating indicates a 
more efficient system when compared with a system having a lower SEER 
rating. 
One popular method of cooling the air inside a structure that has been 
adopted in many hot climates is the evaporative cooler. Evaporative 
coolers use a simple combination of a water pump, absorbent cooling pads, 
and a fan to provide cool air. Using basic principles of gravity and 
evaporation, air is cooled by forcing it through the evaporative cooler. 
Water is pumped into water-retaining pads which line the interior surface 
of the evaporative cooler and the outside air is drawn into the 
evaporative cooler by a large blower fan. By drawing the outside air 
through the water-soaked cooling pads, heat is transferred from the air to 
the water as water evaporation (heat of vaporization) occurs and the 
cooled air is blown into the structure, thereby cooling the interior of 
the structure. 
While generally effective, evaporative coolers have certain well-known 
limitations. For example, as the outside air temperature increases, the 
evaporation process cannot sufficiently lower the temperature of the air 
in a structure to provide an acceptable temperature for human occupation. 
The evaporation rate, however, will continue to increase as the 
temperature increases. In addition, in very humid climates, evaporative 
coolers can be ineffective for cooling occupied structures at even 
relatively low ambient air temperatures due to the high amount of water 
vapor in the air. Once the air is saturated with water vapor, no 
additional cooling can take place. 
To overcome the limitations associated with evaporative coolers, people 
living in many desert climates have turned to refrigerated 
air-conditioning systems to cool the air inside a structure. Instead of 
using the principles of evaporation, traditional refrigerated 
air-conditioning systems use the properties of refrigerant gases such as 
freon to cool the temperature of the air. 
While very effective, refrigerated air-conditioning systems suffer from 
several undesirable characteristics. Foremost, these systems are 
relatively expensive to operate when compared to the nominal operational 
costs associated with most evaporative coolers. During the hottest part of 
the summer in more severe desert climates, the cooling costs associated 
with supplying electricity for a refrigerated air-conditioning system for 
even modest-sized homes can become exorbitant. Secondly, the compressors, 
fans, and motors used in typical residential air-conditioning systems are 
very loud and can contribute to a high level of ambient noise in some 
residential areas. In addition, the size and shape of the various 
components of the refrigerated air-conditioning system makes them somewhat 
unsightly next to a residence. Finally, the continued growth in the use of 
air-conditioning systems requires an ever-increasing expenditure of 
precious resources to generate the electricity necessary to operate the 
systems. 
In some areas of the country, evaporative coolers and refrigerated air 
conditioning systems are both used, during different parts of the season, 
to cool the air inside a structure. In a typical scenario, an evaporative 
cooler may be used to reduce the ambient air temperature inside a 
structure during the relatively cooler and drier spring and early summer 
months (i.e., April, May, and June). Then, once the outside ambient air 
temperature and/or humidity has exceeded the capabilities of the 
evaporative cooler, typically in July, August, and possibly September, the 
evaporative cooler is switched off and the refrigerated air-conditioning 
system is used to reduce the ambient air temperature. Towards the end of 
the summer months as the fall season arrives, temperatures and humidity 
levels drop, and the evaporative cooler may once again be adequate to 
provide the desired cooling effect. While the use of both systems is more 
efficient than either system alone, these hybrid systems still suffer from 
the deficiencies associated with the respective component systems 
described above. 
What is needed, therefore, is an apparatus and method for more efficiently 
cooling the interior of structures, particularly in hot desert climates 
where refrigeration is the primary method of cooling, while simultaneously 
decreasing the overall consumption of electric power. Without developing 
more efficient methods for providing cool air in hot desert climates, 
operating expenses borne by consumers for refrigerated air-conditioning 
systems will continue to rise and our earth's natural resources will 
continue to be diminished at an overly excessive rate. 
DISCLOSURE OF INVENTION 
A preferred embodiment of the present invention utilizes a swimming pool, 
the swimming pool water pump, an evaporative cooler, and a refrigerated 
air-conditioning system with a water-cooled condenser to provide a more 
energy-efficient means (SEER values up to 24 or more, including the 
evaporative cooler power consumption) for cooling a house, an office, a 
retail store, or other enclosed space. In addition, by selectively using 
the evaporative cooler to cool the interior of the attic space in a 
structure, the attic space acts as a buffer zone between the outside hot 
air and the sun-heated roof surfaces and the area inside the structure 
which is to be cooled. The introduction of the cooled output air from the 
evaporative cooler into the attic space significantly reduces the 
temperature differential between the air inside the dwelling portion of 
the structure and the ambient air temperature in the attic space. This, in 
turn, reduces the cooling load on the refrigerated air-conditioning 
system, that is used to cool the dwelling space inside the structure. The 
combination of the two cooling systems, operating in tandem to control the 
air temperature inside the structure, is more efficient than either system 
operating independently. This system will reduce the overall operating 
costs and energy consumption required to cool the interior space of a 
given structure by as much as 50%. 
Additionally, since water-cooled condensers are more energy-efficient than 
the typical air-cooled condenser coils used in most residential and other 
small air-conditioning systems, the use of a water-cooled condenser in 
conjunction with the present invention further reduces operating costs. A 
refrigerated air-conditioning system utilizing a preferred embodiment of 
the present invention utilizes smaller components and is less obtrusive, 
visually and audibly, than a more conventional cooling system. Finally, in 
a preferred embodiment of the present invention, a swimming pool or other 
water storage source, such as the water reservoir of the evaporative 
cooler, is used to provide water for the evaporative cooler and for the 
water-cooled condenser as an integral part of the air-cooling system. 
Depending upon operating parameters, it may be desirable to include a 
mechanism or method for controlling the hardness of water supplied from 
the water storage source to the water-cooled condenser. A purge-type of 
mechanism that removes a portion of high-hardness water is preferred. Such 
a mechanism may include a conductivity sensor positioned to contact water 
supplied to the condenser, a hardness monitor linked to the sensor, and 
control valve triggered to open by the hardness monitor.

BEST MODE FOR CARRYING OUT THE INVENTION 
The preferred embodiments of the present invention provide an 
energy-efficient means of cooling ambient air temperature. Various 
preferred embodiments of the present invention can be readily adapted to 
provide air-cooling capabilities for homes, offices, and other structures 
designed for human occupation or for storing temperature sensitive items 
such as food and other perishables. In addition, other preferred 
embodiments may be used to cool the ambient air temperature in other 
storage facilities and may also be used in conjunction with more 
traditional air-cooling systems to provide higher efficiencies and reduced 
operating costs. 
DETAILED DESCRIPTION 
In accordance with a preferred embodiment of the present invention, an air 
cooling system uses a combination of a swimming pool, a swimming pool 
pump, an evaporative cooler, and a refrigerated air-conditioning system to 
provide a more energy efficient means for cooling a house, an office, a 
retail store, or other structure. A secondary benefit of installing a 
preferred embodiment of the present invention is the general cooling 
effect provided for the water in the swimming pool. 
The evaporative cooler can be used to cool either the attic space or the 
living spaces of a structure, as desired. During the evening and night 
hours, the output air from the evaporative cooler can be used to directly 
cool the living spaces of a home or other structure. Then, in the early 
morning hours, the cool air provided by evaporative cooler 120 can be 
redirected into the attic space of the home or structure. Once the cool, 
moist air from the evaporative cooler is no longer directed into the 
living spaces, the humidity in the living space will begin to drop as the 
outside temperature rises. This procedure minimizes the residual humidity 
level in the living spaces and can prevent the unnecessary accumulation of 
water vapor in the living spaces and the furniture, carpets, drapes, etc. 
contained in the living spaces. The cool air flowing through the attic 
space reduces the heat flow from the attic space to the living spaces, 
thereby slowing the normal temperature rise in the living spaces. Then, 
during the course of the day, as the outside temperature continues to 
increase and the temperature level in the living spaces becomes 
uncomfortable, the output from the evaporative cooler is once again 
directed into the living spaces to provide cooler air for reducing the 
ambient air temperature in the living spaces. 
Referring now to FIG. 1, an air-cooling system 100 in accordance with a 
preferred embodiment of the present invention includes: a water source 
110; a condenser pump 115; a pool pump 116; a water filter 117; an 
evaporative cooler 120; a bypass louver 125; a refrigerated 
air-conditioning system 130; water supply piping 140; filtered water 
return piping 141; a structure 170; an attic vent 190; return air ductwork 
195; an evaporative cooler pump 310; alternate water source supply valve 
112; valve 151; and check valves 330 and 331. Structure 170 includes: an 
air supply ductwork 150; an upduct 175; a living space 180; and an attic 
space 160. 
Water source 110 is a water storage unit and may be any relatively large 
body or container of water suitable to supply the amount of water 
necessary for system 100 to operate as described herein. In the 
residential setting, water source 110 may be a swimming pool. In an 
industrial setting, water source 110 may be a water storage tank or a 
series of water storage tanks. In an agricultural setting, water source 
110 may be a pond. 
Bypass louver 125 is a pivotable airflow directional control mechanism. By 
moving bypass louver 125 from one position to another, the output airflow 
from evaporative cooler 120 may be directed into at least two different 
areas, namely attic space 160 and living space 180. Attic vent 190 is 
provided to allow hot air to escape from attic space 160 and return air 
ductwork 195 will supply input air for refrigerated air-conditioning 
system 130. 
The exact size and number of components, horsepower rating of motors, 
length of tubing, and other factors relating to performance of system 100 
as shown in FIG. 1 can be modified and adapted to suit the specifications 
of almost any given cooling requirement. For example, if more air flow is 
desired, the size of the fan or the fan speed in evaporative cooler 120 
may be increased. If a larger volume of refrigerated air is required for a 
specific environment, the size of refrigerated air-conditioning, system 
130 may be increased. For both aesthetic purposes and economic reasons, 
smaller, less obtrusive equipment should be selected wherever possible. In 
one preferred embodiment of the present invention, the main components for 
refrigerated air-conditioning system 130 are relatively small and may be 
placed out of sight behind evaporative cooler 120. 
Wherever possible, the preferred embodiments of the present invention will 
include an arrangement where the cooling components (evaporative cooler 
and refrigerated air-conditioning system 130) are placed on the ground to 
reduce exposure to sun and the heat generated from roofing materials. This 
desired placement will also allow easy access to the components for repair 
and maintenance. In addition, when the components are placed on the 
ground, less noise from the equipment will be conducted through the 
building structure into the living spaces. If the cooling components are 
placed on the ground, it may be necessary to have a small pump (1/8 hp) to 
ensure circulation back to water source 110. However, as explained below, 
the requirement for a small pump can be obviated with additional system 
modifications. 
The water supply portion of piping 140 is preferably PVC or ABS piping, 
sized as necessary to provide the appropriate flow rate from water source 
110 to refrigerated air-conditioning system 130 and evaporative cooler 
120. The portion of piping 140 used to return the water from evaporative 
cooler 120 to water source 110 is preferably standard ABS plastic drain 
piping. This piping may be sized from 2" diameter to 4" diameter, 
depending on the desired flow rate, "head pressure" (gravitational force 
and frictional flow losses associated with water systems) and other 
factors explained below. If the return path for the water to water source 
110 has a sufficient negative gradient, the small pump mentioned above 
will not be necessary and may be eliminated. The pressure drop in filtered 
water return piping 141 usually supplies enough pressure to pump water 
through refrigerated air-conditioning system 130 and evaporative cooler 
120. 
Air Flow--Evaporative Cooler Mode 
As shown in FIG. 1, in a preferred embodiment of the present invention, the 
air flow for structure 170 can be routed into structure 170 in several 
different ways in order to accommodate the most effective and efficient 
use of system 100 for cooling the temperature of the air contained in 
structure 170. Whenever ambient air conditions outside structure 170 
permit, cool air for the interior of structure 170 will be supplied, as 
needed, from evaporative cooler 120 with evaporative cooler pump 310 
recirculating the water for evaporative cooler 120. When system 100 of 
FIG. 1 is operated using only evaporative cooler 120, water can be 
supplied to system 100 through alternate water source supply valve 112 
from a water source other than water source 110 (i.e., the city water 
system). In that case, refrigerated air-conditioning system 130 is shut 
off and valve 151 is closed. Valve 151 is closed to prevent water from 
evaporative cooler 120 from draining back into water source 110. Further, 
bypass louver 125 is positioned so that the air flowing out of evaporative 
cooler 120 is directed into air supply ductwork 150. Air supply ductwork 
150 can be any type of air supply system used by those skilled in the art 
to deliver air into the various desired portions of structure 170. 
In addition, in one preferred embodiment of the present invention, an 
upduct or vent 175 is supplied between living space 180 and attic space 
160. Upduct 175 is preferably located on the side of structure 170 
opposite evaporative cooler 120 to enhance air circulation. The pressure 
differential will enhance air flow and move the cool air more effectively 
through structure 170. In addition, it is important to note that a window 
or other opening may also serve as an upduct or vent for system 100. 
However, this will reduce the overall efficiency of system 100 because the 
cool air from living space 180 will not be vented through attic space 160, 
which is the most effective use of the cooled air from living space 180. 
Air in living space 180 will flow into attic space 160 through upduct 175 
and be vented to the outside via attic vent 190, thereby cooling attic 
space 180 as the air passes through. 
When using only evaporative cooler 120 to cool living space 180, the fan in 
evaporative cooler 120 may be operated 24 hours a day. Evaporative cooler 
pump 310 can also operate 24 hours a day. The monthly cost for using 
evaporative cooler 120 to cool a home with 2,000 sq/ft of living space 180 
is approximately $10/month in the greater Phoenix area. Typically, louver 
125 is positioned so that the output air from evaporative cooler 120 can 
be used to cool living space 180 during the evening and night hours. By 
using this approach, the air in living space 180 and attic space 160 will 
be cooled to a temperature of approximately 70.degree. F. by morning. 
In the morning, louver 125 can be repositioned and the output air from 
evaporative cooler 120 can be redirected into attic space 160. With no 
cooling provided for living space 180, the ambient air temperature in 
living space 180 will gradually begin to rise, even though attic space 160 
is being cooled. During this time, the humidity in living space 180 will 
gradually diminish, making living space 180 less humid and allowing the 
carpets, furniture, and drapes in living space 180 to lose some absorbed 
moisture previously introduced by evaporative cooler 120. 
When the ambient air temperature in living space 180 exceeds the desired 
level, louver 125 is repositioned so the output air from evaporative 
cooler 120 is redirected into living space 180. The ambient air 
temperature in living space 180 will gradually decrease to a more 
comfortable level. While using only evaporative cooler 120, neither 
refrigeration system 130 nor water source 110 are operated as part of 
system 100. Depending on the temperature and humidity conditions, 
evaporative cooler 120 may be used to cool only attic space 160, thereby 
maintaining a low humidity level in living space 180 yet still effectively 
reducing the heat transfer from attic space 160. 
Air Flow--Refrigerated Air-Conditioning Mode 
Whenever the ambient air temperature and/or humidity outside structure 170 
exceeds the capability of evaporative cooler 120 to effectively cool the 
air for use in cooling living space 180, bypass louver 125 is positioned 
so that the air flowing from evaporative cooler 120 is directed into attic 
space 160. In this case, both evaporative cooler 120 and refrigerated 
air-conditioning system 130 are operational, and refrigerated 
air-conditioning system 130 will provide cool air for living space 180. 
The air flow from evaporative cooler 120 will reduce the ambient air 
temperature in attic space 160 from approximately 140.degree. F. to 
approximately 100.degree. F. when the ambient air temperature outside 
structure 170 is approximately 110.degree. F. To operate system 100 in 
this manner, evaporative cooler pump 310 is turned off, condenser pump 115 
is turned on, and valve 151 is opened. 
This significant decrease in ambient temperature for the air in attic space 
160 will, in turn reduce the cooling load on refrigerated air-conditioning 
system 130, and thereby effectively reduce the operational expenses for 
system 100. In this mode, attic vent 190 vents hot air from attic space 
160 to the outside. When using refrigerated air-conditioning system 130 to 
provide cool air for living space 180, the previously mentioned upduct or 
vent 175 is closed to prevent the cool air from being vented to attic 
space 160. Makeup or return air is supplied to refrigerated 
air-conditioning system 130 via return air ductwork 195. 
Referring now to FIG. 2, a refrigerated air-conditioning system 130 in 
accordance with a preferred embodiment of the present invention includes: 
evaporator 205; evaporator fan motor 207; expansion valve 209; 
filter/drier 215; fill/evacuation valves 220 and 240; ball valves 225 and 
230; gauges 245 and 255; condenser 260; compressor 270; sight glasses 210 
and 265; and piping 290. 
System 130 will typically utilize freon gas for refrigeration purposes but 
given the current environmental pressures on society to reduce or 
eliminate freon from refrigeration systems, it is contemplated that other 
gases which are known to those skilled in the art will be adapted for use 
with system 130 as well. 
Condenser 260 and compressor 270 together are the "condensing unit" for the 
refrigerant in system 130. The condensing unit functions to condense the 
refrigerant vapor to a liquid. This is accomplished by compressing the 
refrigerant and cooling it until it liquefies. Compressor 270 increases 
the pressure of the refrigerant vapor and the cool water flowing through 
condenser 260 removes the heat from the refrigerant vapor to condense the 
refrigerant to a liquid. 
Condenser 260 is a durable, high-efficiency, water-cooled condenser that 
provides heat transfer capabilities for system 130. Condenser 260 must 
present adequate surface area to remove the heat from the freon that flows 
through condenser 260. For the purposes of illustration to support system 
130 as shown in FIG. 2, condenser 260 is approximately 4" by 4" by 18" 
with multiple stacked plates for heat transfer. It is desirable to provide 
a condenser 260 which causes a turbulent flow over the surface area of 
condenser 260 to maximize heat dissipation from the refrigerant vapor to 
the water flowing through condenser 260. Water is supplied to condenser 
260 by condenser pump 115 (see FIG. 1). The temperature of the water 
entering condenser 260 at inlet opening 261 is approximately 85.degree. F. 
(i.e., the temperature of water source 110 of FIG. 1) and the temperature 
at outlet opening 262 will be approximately 90.degree. F. The outlet water 
is supplied to evaporative cooler 120. 
One specific example of a water-cooled condenser suitable for use with 
refrigerated air-conditioning system 130 is condenser CB50-38 manufactured 
by Alfa-Laval in Sweden. While other types of condensers may be used, they 
are generally larger, less efficient, and/or more susceptible to damage. 
One specific example of a compressor suitable for use with refrigerated 
air-conditioning system 130 is the Copeland ZR28K1-PFV, rated at 3 tons. 
Refrigerant Flow 
Referring now to FIG. 2, the refrigerant flow for system 100 can be 
illustrated. Refrigerant vapor flows from evaporator 205 to compressor 270 
and from compressor 270 to condenser 260. Evaporator 205 is typically 
mounted on a furnace unit (not shown) located within structure 170. Most 
furnace units include provisions to mount an evaporator such as evaporator 
205 on the top of the furnace unit. The blowers of the furnace unit blow 
air from living space 180 through a heat exchanger to evaporate the 
refrigerant. The liquid refrigerant is boiled in the evaporator, thereby 
cooling the air, and the liquid refrigerant becomes a gas. The gaseous 
refrigerant is compressed by compressor 270 and is then routed to 
condenser 260 where the heat is removed by the cool water flowing through 
condenser 260. One heat exchanger suitable for use with system 100 is 
model TXC049A4H supplied by Trane. The exact location of evaporator 205 
will be dictated, in large part, by the manufacturer's specification and 
installation directions. System 100 can accommodate any practical location 
for evaporator 205. 
Sight glasses 210 and 265 are used to verify that the liquid refrigerant is 
free of vapor bubbles and is completely condensed as it enters evaporator 
205. Ball valves 225 and 230 can be used to isolate the condensing unit 
from the evaporator unit during maintenance. Filter/drier 215 is used to 
remove any undesired water and sediment or particulates from the 
refrigerant as it flows through system 130. Fill/evacuation valves 220 and 
240 can be used to add or remove refrigerant from system 130. Gauges 245 
and 255 are used to monitor the pressure in system 130. 
It should also be noted that the specific valves, gauges, and other details 
shown in FIG. 2 are not all necessary for all preferred embodiments of 
system 130. Many of these devices are included merely for operator 
convenience and to aid in troubleshooting system 130. In order to reduce 
initial installation costs, many of the valves, gauges, and sight glass 
elements shown may not be included in all preferred embodiments of 
refrigerated air-conditioning system 130. 
Water Flow 
Referring now to FIGS. 1, 2, and 3, the water flow for system 100 of FIG. 1 
is illustrated. When refrigerated air-conditioning system 130 is 
operational, evaporative cooler pump 310 is shut down, valve 151 is 
opened, alternate water source supply valve 112 is closed, and water from 
water source 110 is supplied by condenser pump 115 to condenser 260. 
Beginning with the water in water source 110, represented here as a 
residential swimming pool, the water temperature is nominally 85.degree. 
F. as it exits water source 110 and is pumped through system 100 by 
condenser pump 115. In one preferred embodiment of system 100, condenser 
unit 340 (non-phantom view of FIG. 3) is located between water source 110 
and the water inlet point for evaporative cooler 120. In this case, the 
water is supplied by condenser pump 115 to condenser 260. 
After the water has flowed through condenser 260, the heat contained by the 
freon or other refrigerant has been transferred to the water. The 
temperature of the water as it exits condenser 260 at outlet 262 (as shown 
in FIG. 2) is approximately 90.degree. F. The water is then supplied as 
inlet water to the top of evaporative cooler 120. As the water flows into 
evaporative cooler 120, it is gravity fed and then absorbed into a series 
of pads that form the walls of evaporative cooler 120. A portion of the 
water is then evaporated, thereby cooling the water and the air passing 
through evaporative cooler 120 to a temperature of approximately 
80.degree. F. Any unevaporated water is returned to water source 110. 
Thus, the pool water temperature drops as the 80 F. return water mixes 
with the 85.degree. F. water stored in water source 110. 
Alternatively, as shown in phantom view in FIG. 3, condenser unit 340 may 
be located between the water outlet point for evaporative cooler 120 and 
water source 110. If condenser 260 is placed in the location indicated by 
the phantom view for condenser unit 340, the water is routed into 
evaporative cooler 120 before being supplied to condenser 260. In that 
case, the outlet water from evaporative cooler 120 becomes the inlet water 
for the bottom of condenser 260 and the outlet water from condenser 260 is 
returned to water source 110. 
Condenser pump 115 is sized according to the cooling needs of each specific 
application environment. For a typical residential structure of 
approximately 2,000 sq. ft., a 10 gallons per minute (GPM) pump is 
suitable. Given a required flow estimate of 3 GPM/ton of cooling required, 
a 10 GPM pump will allow for approximately 31/3 tons of cooling to be 
provided by system 340. This level of cooling output is sufficient to cool 
a 2,000 sq. ft. home during the summer in a typical desert climate such as 
Phoenix, Ariz. Obviously, those skilled in the art will recognized that 
the size of condenser pump 115 and the associated GPM rating can be 
optimally selected to provide different levels of cooling for different 
environments. 
In addition, based on the location of the various components of system 100, 
the pressure rating of condenser pump 115 may be increased or decreased as 
necessary to compensate for any head pressure developed in system 100. 
Finally, most swimming pools are equipped with a water filter pump 116 
which is used to clean the water in the swimming pool by pumping it 
through water filter 117. This existing swimming pool water filter pump 
116 can be utilized in conjunction with system 100 and may, in optimal 
circumstances, eliminate the need for condenser pump 115. 
Whenever water filter pump 116 is running, it will discharge part of its 
filtered water back to evaporative cooler 120 and condenser 260. Condenser 
pump 115 will not be used at this time. Check valve 331 will prevent the 
water from flowing back through condenser pump 115. This operational mode 
will reduce the power consumption requirements for cooling structure 170, 
and will effectively increase the SEER number for system 100. 
When compressor 270 is not running, the water flow from water filter pump 
116 will continue to supply evaporative cooler 120 and evaporative cooler 
120 will be used to cool both attic space 160 and the water contained in 
water source 110 as described earlier. Using this procedure, water filter 
pump 116 not only filters the water for water source 110, but also 
provides a contribution for the cooling of structure 170 and for reducing 
the temperature of water source 110 with no additional expense for 
electrical power consumption. 
When water filter pump 116 is not running and refrigeration system 130 is 
used, condenser pump 115 will operate to circulate water for the cooling 
process. When neither water filter pump 116 nor condenser pump 115 are 
running, evaporative cooler pump 310 can recirculate water for evaporative 
cooler 120 and evaporative cooler 120 can continue to operate, thereby 
reducing the ambient temperature in attic space 160 and the heat load on 
structure 170. To operate in the fashion, valve 151 should be closed and 
alternate water source supply valve 112 should be opened. It is possible 
to leave both valves in the closed position and use the fan in evaporative 
cooler 120 to circulate ambient air in attic space 160 without supplying 
any water for cooling purposes. While not as effective, this option will 
still provide some measurable cooling effect and help to reduce the rate 
of temperature rise in attic space 160. 
Check valve 330 prevents the water pumped by condenser pump 115 from 
flowing back through water filter pump 116 and the associated pipes to 
water source 110. There are many ways to isolate the pumps from each other 
besides using check valves 330 and 331. As long as water filter pump 116 
is running, it will be cooling the water in water source 110. The colder 
the water that is supplied to condenser 260, the more efficient system 130 
will be in removing heat from the refrigerant flowing through system 130. 
Once again, a benefit is provided both in cooler water for swimming in 
water source 110 and in reduced operational costs for system 100. 
When cool air for the interior of structure 170 is to be supplied by 
evaporative cooler 120, evaporative cooler pump 310 is turned on, valve 
151 is closed, and alternate water source supply valve 112 is opened. 
Whether the water for evaporative cooler 120 is supplied from evaporative 
cooler pump 310 or from condenser pump 115, it is preferably introduced 
into evaporative cooler 120 by a separate header to prevent cross coupling 
of the two water sources. Alternatively, a single header could be used if 
source isolation was insured by installing check valves in the appropriate 
supply lines. The water supply header is typically constructed from a 
perforated thin-walled PVC pipe that is placed around the top of the 
interior of evaporative cooler 120 to distribute the water to the pads 
inside evaporative cooler 120. 
Check valve 331 is provided to prevent backflow into water source 110 when 
condenser pump 115 is shut off and to isolate condenser pump 115 from 
water filter pump 116. Check valve 331 also keeps condenser pump 115 
primed for use if the condenser pump 115 is positioned above the surface 
of the water contained in water source 110. In addition, this will reduce 
the delay time in supplying water to condenser 260 by keeping pipes 140 
full of water. 
Alternative Embodiment 
Referring now to FIG. 4, an alternative preferred embodiment for the water 
flow of system 100 of FIG. 1 is shown. Such a water flow arrangement is 
compatible with all of the various arrangements for air flow and 
refrigerant flow discussed above. A key feature of the water flow 
arrangement shown in FIG. 4 is that water source 110 shown generically in 
FIGS. 1-3 is specified to be a water reservoir 410 of evaporative cooler 
120. In general, evaporative coolers are fabricated with some sort of 
water reservoir designed to collect unevaporated water that drains from 
the cooling pads (not shown) within the evaporative cooler and to provide 
a source of water from which evaporative cooler pump 310 can recirculate 
water back to the top of the cooling pads of evaporative cooler 120. In 
this manner, an amount of water may be placed in water reservoir 410 and 
recirculated through evaporative cooler 120 to keep the cooling pads 
water-soaked and provide the desired cooling effect. 
In many conventional self-contained evaporative coolers, a water reservoir 
410 is created by providing a collection pan positioned beneath the 
cooling pads to receive unevaporated water that drains from the cooling 
pads. Typically, the collection pan is capable of holding several gallons 
of water and evaporative pump 310 rests in the pool of water established 
in water reservoir 410. Evaporative cooler pump 310 provides recirculating 
water to the cooling pads through tubing or piping connected to a water 
distributor at the top of the cooling pads as described above. Also, such 
collection pans often include a drain hole in the bottom for draining 
water reservoir 410 at the conclusion of the hot season. Such a drain hole 
provides a suitable location for connecting condenser unit 340 to water 
reservoir 410 using piping 140. 
As the initial amount of water evaporates during operation of evaporative 
cooler 120, make-up water to replace the evaporated water may be added to 
water reservoir 410. Any method or mechanism known to those skilled in the 
art for adding make-up water may be used in the alternative preferred 
embodiment of FIG. 4. One common mechanism for adding make-up water is 
shown in FIG. 4 as a float-operated valve 400 in combination with a float 
405. As a water level (not shown) in water reservoir 410 decreases, float 
405 lowers in position until, at a preselected position, the mechanism of 
float-operated valve 400 allows the valve to open and resupply water 
reservoir 410 with water. The increasing water level then raises the 
position of float 405 sufficiently to cause the closing of float-operated 
valve 400. By this mechanism, the water level of water reservoir 410 can 
be maintained automatically within a desired range, thus, a source from 
which evaporative cooler pump 310 may recirculate water is always 
provided. 
Frequently, an off-the-shelf evaporative cooler includes in a single unit 
the water reservoir 410, float-operated valve 400, float 405, and 
evaporative cooler pump 310, along with the necessary piping to accomplish 
the evaporative cooler 120 recirculation shown in FIG. 4. The scope of the 
present alternative preferred embodiment includes such a self-contained 
unit as well as arrangements in which the components discussed above are 
not provided in a single unit, although the self-contained type of unit is 
preferred an readily available. 
It has been determined that a typical water reservoir 410 associated with 
an evaporative cooler 120 usually contains an amount of water suitable to 
supply the water needed for system 100 to operate as described herein. 
Accordingly, piping 140 is provided to couple evaporative cooler reservoir 
410 to condenser unit 340 through condenser pump 115 as shown in FIG. 4. 
Once the water from water reservoir 410 passes through condenser unit 340, 
preferably the water returns to evaporative cooler 120, where the heat 
acquired from water-cooled condenser 260 may be dissipated using the 
evaporative process occurring in evaporative cooler 120. However, the 
water exiting condenser unit 340 may alternatively be discharged, although 
it is not preferred unless the discharged water may be put to some other 
use. Such other uses may include watering vegetation, supplying water to 
an industrial process, and other uses known to those skilled in the art. 
As discussed above, when condenser pump 115 is in operation it is not 
necessary to simultaneously operate evaporative cooler pump 310. However, 
it may be operated simultaneously if needed depending on the flow rate 
provided by condenser pump 115 and the total flow rate needed for 
evaporative cooler 120. Additionally, the functions provided by 
evaporative cooler pump 310 may be provided by condenser pump 115 alone, 
allowing elimination of evaporative cooler pump 310. In the arrangement of 
FIG. 4 where water exiting condenser unit 340 is returned to evaporative 
cooler 120, the invention provides both the benefits and cooling air and 
cooling water. However, if all of the water from condenser unit 340 is 
discharged and no water is recirculated through evaporative cooler pump 
310, then the invention only addresses the cooling of air and not the 
cooling of water. In such an arrangement, the water provided to 
evaporative cooler 120 through valve 112 must be routed directly to the 
cooling pads of evaporative cooler 120 rather than to water reservoir 410. 
The advantages of a FIG. 4 type of arrangement are that evaporatively 
cooled air may be provided to one location in a structure, such as an 
attic space, and air cooled by refrigeration may be provided to a 
different location within a structure, such as a living space or working 
space. 
Although not preferred, it is also within the scope of the present 
invention that refrigerated air is supplied to a working or living space, 
but no evaporatively cooled air is supplied to another location within a 
structure. In such an arrangement the objective of coupling water cooled 
condenser 260 to water reservoir 410 is to provide a recirculating supply 
of cooled water to assist in generating refrigerated air. Such an 
arrangement may be desirable in regions that experience high humidity 
conditions. In high humidity conditions, only a relatively small amount of 
air cooling can be achieved by an evaporative cooler, thus diminishing a 
significant portion of the advantage of providing evaporatively cooled air 
to an attic space. However, an evaporative cooler 120 may be used to 
efficiently dissipate the heat collected from water cooled condenser 260 
by the recirculating water. Thus, while the full benefits of all 
advantages of the present invention are best suited for regions of low 
humidity, such as hot, desert climates, some of the advantages of the 
present invention may nevertheless be obtained in other regions. 
As indicated above, it is preferred that the water used in evaporative 
cooler 120 and in condensing unit 340 is recycled to evaporative cooler 
120 to minimize the water demands of a system according to the present 
invention. Because some of the water is lost to evaporation in the 
evaporative process and the water is continuously recirculated, it is 
likely that the quality of the recirculating water will diminish gradually 
as the concentration increases of various chemical species found in 
residential and industrial water. Various salts of magnesium and calcium, 
such as calcium carbonate contribute to the increase of a condition known 
as water hardness. As hardness increases, the likelihood of mineral 
deposits accumulating on piping and equipment that contacts the water also 
increases. Such accumulations can require replacement and cleaning to 
prevent damage and maintain the level of performance, especially of heat 
exchange equipment such as condenser unit 340. Accordingly, measures are 
needed to prevent the accumulation of mineral deposits by maintaining 
hardness at a sufficiently low level. 
The scope of the present invention includes any mechanism or method known 
to those skilled in the art for controlling the hardness of water supplied 
from water reservoir 410 to condenser unit 340. However, for the sake of 
simplicity and cost minimization, a purge-type of mechanism is preferred 
and is shown in FIG. 4. Such a mechanism includes a hardness sensor 420 
positioned to contact water supplied to condenser 260 and a hardness 
monitor 425 linked to hardness sensor 420. Hardness sensor 420 transmits a 
signal to hardness monitor 425 that gives a quantified indication of 
hardness for the water. Hardness monitor 425 is, in turn, linked to a 
control valve 430. When hardness exceeds a maximum limit, hardness monitor 
425 generates a signal to control valve 430 to open for a selected time, 
thus purging from the system a selected amount of high hardness water 
through discharge piping 440. Hardness sensor 420 may be a conductivity 
sensor or another type of sensor providing the indicated functions. Also, 
control valve 430 may be a solenoid valve or another type of valve 
providing the indicated functions. Further, discharge piping 440 may be 
any type of tubing or piping, including flexible hose, that allows proper 
discharge of purged high hardness water, including in some circumstances a 
typical garden water hose. 
Selection of the amount of time to leave control valve 430 open may be 
preselected such that, given the flow rate of water through discharge 
piping 440 to discharge point 450, a known volume of water may be purged. 
Alternatively, hardness monitor 425 may be set such that control valve 430 
remains open until the quantified indication of hardness produced by 
hardness sensor 420 reaches a minimum limit. Other control mechanisms are 
also conceivable. Also, the maximum limit is preferably 400 ppm hardness 
and the minimum limit is preferably 350 ppm, although each limit is 
dependent upon the particular environment in which the present invention 
is operating. The two preferred limits are suitable for a residential 
setting where residential water having a hardness of 200 ppm is provided 
as the make-up water. If the equipment used in such a setting is 
particularly resistant to mineral deposits, then the maximum limit may be 
higher than 400 ppm. Similarly, if equipment is particularly susceptible 
to influence by mineral deposits, then the minimum limit may be less than 
350 ppm. Also, the difference between the maximum and minimum limit may be 
larger or smaller than 50 ppm, depending upon a need or a lack of a need 
to control hardness within a certain range. 
Once control valve 430 opens and purging begins, the water level within 
water reservoir 410 will decrease, causing the position of float 405 to 
lower and open float-operated valve 400. The make-up water entering water 
reservoir 410 will then dilute the concentration of chemical species in 
the water to reduce hardness. A variety of positions within the water flow 
arrangement of FIG. 4 is conceivable for hardness sensor 420 and control 
valve 430. The primary concern is that water supplied to condenser 260 is 
kept within a preselected range of hardness, thus hardness sensor 420 can 
be placed at any location where it contacts water going to or coming from 
condenser 260. Similarly, the purge of water from the system may occur 
from water reservoir 410 as shown or from another suitable location within 
the arrangement shown in FIG. 4. Further, it is also conceivable that a 
different method or mechanism for adding makeup water to water reservoir 
410 may be used in conjunction with the above described mechanism for 
controlling hardness. 
Other possible mechanisms for controlling hardness include those that are 
adapted to selectively removing chemical species from water that cause 
hardness, such as reverse osmosis mechanisms, ion exchange mechanisms, 
filters, and other mechanisms known among those skilled in the art to 
combat hardness. Additionally, mechanisms may also be used that add 
selected amounts of one or more chemical agents that are adapted to 
counteracting the effects of water hardness rather than physically 
removing chemical species from the water. It is an advantage of the 
preferred purging mechanism for controlling hardness that little upkeep 
and maintenance is required after a one-time purchase and installation 
cost little. Also, the water purged through discharge piping 440 to 
discharge point 450 may be used as a beneficial source of water for some 
other purpose, such as watering vegetation or use in an industrial 
process, reducing the water demands for such other purposes. The 
alternative mechanisms for controlling hardness discussed herein are 
suitable for the present invention, but may be more costly and require 
more maintenance and upkeep than the preferred mechanism. 
While the invention has been particularly shown and described with 
reference to exemplary embodiments thereof, it will be understood by those 
skilled in the art that changes in form and details may be made therein 
without departing from the spirit and scope of the invention. Accordingly, 
unless otherwise specified, any dimensions of the apparatus indicated in 
drawings or herein are given as an example of possible dimensions and not 
as a limitation. Similarly, unless otherwise specified, any sequence of 
method steps indicated herein is given as an example of a sequence and not 
as a limitation.