Air conditioner and heat dispenser

A heating and cooling air conditioning system includes serially arranged conductive and evaporative pad heat exchangers through which circulating air to be heated or cooled is moved by a blower. The conductive heat exchanger contains a liquid heat exchange medium that is selectively solar heated or cooled by an evaporative heat exchanger, for example, a cooling tower. A single tank reservoir is provided for the heat exchange medium. A singular air valve controls flow of air into the heat exchangers as well as flow of return air to exhaust. A domestic hot water heating tank is disclosed with a heat exchange loop provided in the solar heated heat exchange medium reservoir tank for heating the service hot water supply.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a roof-mounted air conditioning system using a 
conductive heat exchanger and an evaporative pad heat exchanger to 
selectively heat or cool an enclosure. 
2. Description of the Prior Art 
The present invention is concerned with an air conditioning system adapted 
for installation in conjunction with a heat exchanger and an evaporative 
cooler for heating and cooling buildings for year round operation in 
geographical areas having low atmospheric humidity, and in particular to a 
low pressure, high capacity air blower that selectively draws external 
atmospheric air through a heating or cooling heat exchanger and then 
through an evaporative cooler for supplying the building's heating and 
cooling demands. The air conditioning system for the building accordingly 
is so regulated that both heated and cooled air is supplied in suitable 
quantities to achieve the desired heating and cooling despite varying 
environmental conditions. 
Prior art systems for heating and cooling interior spaces by using 
conductive and evaporative heat exchangers mounted in series or parallel 
are shown, for example, in U.S. Pat. Nos. 2,110,024, 3,802,493, 3,833,052, 
4,284,128, and 4,505,327. The aforementioned U.S. Pat. No. 4,505,327 
furthermore shows that the use of a solar heater is known to heat a heat 
exchange medium in a conductive heat exchanger used in an air conditioning 
system of the same general type corresponding to the present invention. 
While the above patents illustrate that the combined effects of conductive 
and evaporative heat exchangers are known, they fail to illustrate a 
system wherein a heating and cooling heat exchange medium is circulated 
through a series of heat exchangers and stored in a single storage tank. 
The prior art, moreover, as exemplified by the above-mentioned patents, 
also fails to provide a conductive heat exchanger through which is 
circulated a heat exchange medium that may selectively be heated by a 
solar heater or cooled by a cooling heat exchanger, such as, for example, 
a cooling tower. 
In accordance with the prior art, roof-top evaporative type heat 
exchangers, even when combined with conductive heat exchangers, are not 
generally provided with simple air control systems for enabling 
circulation of ambient and return air in various proportions through the 
system, or selective exhaust of return air with supply of external ambient 
air only into the system. 
It has also not been generally recognized in the prior art that a simple, 
fully integrated heating and air conditioning system can utilize solar 
heating, conductive and evaporative pad heat exchangers, and a cooling 
heat exchanger whereby circulated air can be heated, cooled, and 
humidified with a minimum expenditure of energy. 
SUMMARY OF THE INVENTION 
The present invention comprises a heating and cooling air conditioning 
system wherein an air duct communicating with a space to be heated or 
cooled and an intake zone outside such space, includes serially mounted 
conductive and evaporative pad heat exchangers through which air to be 
heated or cooled is moved by an appropriate blower. An air directing valve 
selectively permits circulating air to be returned to an exhaust zone and 
external ambient air to be admitted to the heat exchangers. The air 
directing valve may also selectively mix return and ambient air in varying 
proportions upstream of the heat exchangers. 
Heat exchange medium such as water is circulated through the conductive 
heat exchanger and is selectively heated or cooled by solar energy or a 
cooling heat exchanger such as a cooling two. Appropriate valves, pumps 
and controls enable the heat exchange medium to be selectively heated or 
cooled while it is also circulated through the conductive heat exchanger. 
The system is particularly adapted for use in geographic areas where air is 
relatively dry, so that compressor-condenser coolers are not required. 
A single storage tank for the heat exchange medium simplifies the system, 
such tank being used whether or not the heat exchange medium is heated or 
cooled. 
The system can be operated in conjunction with a domestic hot water heater, 
wherein a water heat exchange circuit is provided in heat exchange 
relationship with the storage tank, which in turn is heated by solar 
energy.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The primary heat exchanger system of the invention, generally 10, is shown 
in FIG. 1 mounted upon roof 11 of a dwelling or other building having an 
exterior space 12 and occupant space 13 to be heated or cooled. The system 
10 comprises an external housing 14 generally enclosing an inner capture 
space 15, in which is mounted an air blower 16 powered by an electric 
motor 17 through a flexible drive belt 18. The blower 16 draws external 
air, indicated by arrows 19, from the space 15 and thence into blower air 
inlet 20, and impels it through an outlet duct 21. Blower outlet duct 21 
generally directs the air into an occupant space 13. 
The system 10 may be used as a conventional evaporative pad air cooling 
system. In this event, the air 19 is cooled by evaporation upon passing 
through wetted evaporation pads 22 across the inlet 22a to the housing. 
The pads 22 comprise loosely packed fibers 23, of wood or other water 
permeable material, retained by wire netting 24. Bottom 25 of housing 14 
serves as a reservoir for water 26 admitted from the building water supply 
and controlled to preselected levels 27 by float control valve 28. The 
water 26 is impelled by pad water pump 29 through outlet hose 30 to water 
through 31, by which it is distributed across pad 22 to then flow by 
gravity downwardly to soak fibers 23. Any excess water 26 flows from the 
bottom of pad 22 back into the reservoir. The air 19 is thus ordinarily 
cooled and humidified by evaporative contact with water 26 upon the large 
surface of fibers 23, before passing into and cooling occupant space 13. 
A conductive heat exchanger 32 also is mounted across mounting plates 33 at 
air inlet 22a so as to direct incoming air 19 through passages 34 between 
heat exchange fins 35 in conductive relationship. Water 36, or other 
suitable heat exchange medium, is circulated through passages, not shown, 
in heat exchanger 32, and the air is either heated or cooled by passage 
therethrough, depending on the temperature of the water. The water 36 may 
be stored in a first water tank 37 (FIG. 2) and circulated by water pump 
57 through inlet line 38, first heat exchanger 32, and through water 
outlet line 38a back to tank 37. 
A pivotally movable air shutter valve 41 controls the flow of intake, 
ambient and return air through the system. As shown in FIG. 1, the valve 
comprises a vane 44 disposed upstream of inlet 33 to housing 14 and 
upstream of the conductive heat exchanger 32 and evaporator pad heat 
exchanger 22. The vane 44 may be adjusted to assume positions illustrated 
in hidden lines at 44a, 44b and 44c. At 44a, the vane 44 permits return 
air from space 13 to be fully recirculated through the heat exchangers and 
back to the space 13. At 44b, return air is totally exhausted to an 
exhaust zone through an appropriate outlet of the valve. At the 44b 
position, ambient external air is admitted through ambient zone 39 to be 
drawn by blower 16 through heat exchangers 32 and 22. At the 44c position, 
return and ambient air are mixed in a specified proportion, while a 
proportion of the return air is exhausted. 
A cable control system including appropriate pulleys and wheels 45 and a 
guideline 46 may be used to regulate the position of the vane 44. 
Duct 42 constitutes the return air duct and opening 43 constitutes the 
return air duct discharge in the area of valve 41. However, remote 
electrical sensors and controls may alternately be used, such as those 
which are commonly used for adjusting t.v. antennas. In the latter case, 
the various positions indicated in FIG. 1 by reference numbers 44a, 44b, 
and 44c, can be remotely visualized, but the position of the tabs 44d on 
the line 46 may alternately be used for this purpose. 
A single tank 37 stores heat exchange medium circulated in conductive heat 
exchanger 32 and the cooling heat exchanger 60, to be described 
hereinbelow. 
Preferably, for heating the water in tank 37 a solar heat exchange system 
47 is provided, including a tank 48 alone or in combination with a solar 
heater 48a, which comprises one or more solar panels 49 mounted on roof 
11. As shown in FIG. 2, the solar heater 48a comprises the heat exchanger 
coil 50, which is exposed to sunlight through a transparent window 51 on 
the upwardly sloping surface of tank 48, which has a black back surface 
51a opposite to the wndow 51, a pump 52, an outlet pipe 53 connected to 
the coil 50 at the top of tank 48, and an inlet pipe 54 connected at one 
end to the pump 52 and at the other end to the coil 50 at the bottom of 
tank 48. Thus, the heat exchange water 36 is heated in the solar heater 
48a and this heated water drains into the tank 37, which is advantageously 
a non-pressurized container so that the water 36 can drain from the solar 
heater 48a into the tank 37 by gravity when pump 52 is not activated. 
Advantageously, the solar heater 48a and the tank 37 are interlocked with 
thermostats 55 and 56 for controlling pumps 57 and 52, respectively. To 
this end, when heat is called for in the interior space, and when the 
thermostat 55 detects that the solar heater 48a is up to a desired 
temperature, which is preselected by a movable knob on the thermostat 55, 
the thermostat 55 starts pump 52 to cause water to be circulated through 
the heating coil 50, whereupon the heated water is returned to the tank 37 
at the desired temperature. When the temperature of the water 36 in tank 
37 reaches the desired temperature, which is preselected by the dial on 
the thermostat 56, the thermostat 56 actuates the pump 57 to cause the 
heated water in tank 37 to be circulated through the conductive heat 
exchanger 32. This causes the air 19 entering the occupant space 13 to be 
heated to the desired temperature. Meanwhile, the hydrostat 58, which has 
an adjustable dial for detecting the humidity in the occupant space 13, 
controls the pump 59 which feeds water to the top of the evaporation pads 
22 via water trough 31 at the top of the pads 22. Thus, the air 19 
entering the occupant space 13 through the outlet duct 21 has the desired 
humidity and temperature when heat exchanger 32 is heating the air. 
The system 10 may also be used to cool the occupant space 13 when the water 
36 is cooled. Advantageously, this cooler may be a cooling tower 60, as 
shown in FIG. 2, the means for cooling water 36 is an evaporative cooler 
such as a cooling tower 60. As is conventional, the cooling tower 60 has a 
fan 61 for drawing exterior air through opening 62, through the water 
sprayed into the interior of the cooling tower 60, and out the bottom air 
exit 63. The water level 64 at the bottom of the cooling tower 60 is 
controlled by a float valve 65. The water spray 66 is supplied through the 
outlet pipe 38a of the heat exchanger 32. The air flow through the cooling 
tower 60 cools the water spray 66 by evaporation. Thereupon, the cooled 
water excess drains back to the tank 37 through the drain line 67a, which 
is controlled by a multiple way valve 68a. Ordinarily, the multiple way 
valve 68 supplies cooled water from the cooling tower to the pump 57. 
Thereupon, the cooled water is supplied to the bottom of the first heat 
exchanger 32 through the inlet pipe 38. After existing the heat exchanger 
32 the water in pipe 38a returns to the top of the cooling tower 60 in a 
closed cycle. However, in the event that the cooled water must be stored 
in some sort of accumulator, the valve 68a is opened to drain the cooling 
tower 60 through line 67a, which is connected to the top of the 
nonpressurized tank 37. As will be understood in more detail hereinafter, 
the valve 68a thus enables the return water to flow from either the 
cooling tower 60 or the heat exchanger 32. 
The multiple position valve 70 is position to direct the water from the top 
of the heat exchanger 32 into the tank 37 through return line 71 so as to 
pass water through the valve 68a. 
If desired the multiple way valves 68, 68a, 70 and 72 may be positioned to 
close three connecting pipes, to open two connecting pipes, or to open 
three connecting pipes, as illustrated in FIGS. 3a-3e. For example, valve 
68 may be turned to cause the flow of water 36 from tank 37 through pipe 
72, valve 68, pump 57, and line 38 to heat exchanger 32, and from there 
back to the tank 37 through line 71. Also, the valve 68 may be turned to a 
position where the cooled water in drain 67 along with water in pipe 72 
are pumped through pump 57 into line 38 to provide cooling water for heat 
exchanger 32. Ordinarily, however, valve 68 is used primarily for 
directing water from the cooling tower 60 to the heat exchanger 32 and 
back to cooling tower 60 in a direct one pass cycle. 
When heating is required, the valve 70 is moved to circulate water between 
the tank 37 and the heat exchanger 32 in a closed loop via line 72, pump 
57, and lines 38, 38a and 71. Thus, it will be observed that water can be 
circulated in a closed loop from the heat exchanger 32 to the cooling 
tower 62 via lines 38, 38a, 67 and valve 68 and pump 57. Water can also be 
circulated between the heat exchanger 32 and the tank 37 via line 72, 
valve 68, pump 57 and lines 38, 38a and 71. In addition, water can be 
circulated partially from the cooling tower 62 and partially from the tank 
37 to the heat exchanger 32 by adjusting multiway valves 68, 68a and 70 so 
that flow is divided between two outlets from a common source. Under these 
conditions, flow of water to tank 37 can originate both at cooling tower 
62 and heat exchanger 32. 
In accordance with still another aspect of this invention, the hot water 
tank 73 supplies hot water for the occupants in occupant space 13. To this 
end, as shown in FIG. 2, pump 72 is connected via check via 76 and pipe 77 
to heat exchange coil 78 in tank 37. The coil 78 is connected to the tank 
73 by means of line 79, which empties into tank 73 via an openened pipe 80 
inside tank 73. Also, the city water supply pipe 81 is connected to pipe 
77. Thus, the line from tank 73 to tank 37 is pressurized by the city 
water pressure in line 81. Accordingly, the city water is first heated in 
coil 78 before it enters tank 73. To this end, the pump 74 needs only to 
add a small pressure over the city water pressure to accomplish the 
desired transfer of heat from tank 37 to tank 73. Ordinarily, the water in 
tank 73 is heated by an energy source 82, such as a flame, which is fueled 
by gas or liquid fuel through valve 83, in response to the setting on 
thermostat 84. In accordance with the preferred embodiment of this 
invention, however, the solar heated water 36 may be used to heat the 
incoming water for pressurized tank 73. 
A separate heating coil 85 may be added to tank 37 for using solar heat to 
heat a pool or spa water. 
In operation the incoming water to tank 73 is heated by the solar heated 
water in tank 37. Also, the solar heater 48a heats water in tank 37 for 
heat exchanger 32. Alternately, the cooling tower 60, or another suitable 
heat exchange system and/or cooler, may be used to cool the heat exchange 
fluid in heat exchanger 32. In addition the air 19 may be humidified by 
evaporation pads 22 and also cooled thereby. 
The water from the cooling tower 60 may be used directly in a closed cycle, 
as is ordinarily the case, or may be used with cold water from tank 37 or 
another like tank. To use cold water from tank 37, valve 68 is turned so 
that water from tank 37 is supplied via pump 57 to heat exchanger 32. When 
the cold water from the cooling tower 60 is used in a closed cycle, the 
valve 68 is adjusted so that the pump 57 takes the water from the cooling 
tower 60 via drain 67 and transmits it through pipe 38 to heat exchanger 
32. 
When supply of hot water from tank 37 is desired, valve 68 is set to direct 
water from the tank 37 into line 38 via pump 57, the valve 68 shutting off 
the water supply from the cooling tower 60 via 67 at this time. The 
setting of valve 68 then directs the water through the pipe 38 to the heat 
exchanger 32, and thence back to the tank 37 via valve 70 and pipe 71. 
Note that the valve 70 may be used to direct all of the water from the 
heat exchanger back to the tank 37, or back to the solar heater 48a. 
Alternately, the valve 70 can direct water from the heat exchanger 32 to 
both the solar heater 48a and to the tank 37 via pipes 53 and 71, 
respectively. Pumps 59, 57, 52 and 74 are advantageously positive 
displacement type pumps. Also, the first heat exchanger 32 is 
advantageously a heat exchanger of the type used in an automotive 
radiator. Thus, while the dimensions of the first heat exchanger 32 may be 
different from an automotive radiator, the principles of the automotive 
radiator with fins and a passage therethrough are utilized in accordance 
with this invention. 
In the operation of the various valves, the settings of the valves for 
different scenarios are illustrated in FIGS. 3a-3e. Thus, for example, the 
setting in FIG. 3a shows that the inlet pipe 1 is disconnected from the 
outlet pipes 2 and 3. Thus, all three pipes are effectively closed as 
illustrated in the table of FIG. 3e. On the other hand, the setting of 
FIG. 3b shows a straight through arrangement. In this case, the inlet 1 is 
directly connected to the outlet 3 in a straight line. On the other hand, 
the arrangement of FIG. 3c shows the inlet 1 connected only to the outlet 
2 along a curved path at right angles to the straight through path from 
pipe 1 to pipe 3. Still further, in another arrangement, the inlet pipe 1 
may be connected for flow to both the outlet pipes 2 and 3. In this 
connection, the valve is turned to partially open the two outlet pipes 2 
and 3 so that the pressure is divided therebetween from the inlet pipe 1. 
All of these scenarios are illustrated by the table of FIG. 3e. 
This invention has the advantage of providing solar domestic heating, solar 
domestic hot water, humidity control, and air conditioning, which includes 
cooling with controlled humidification, in year round operation. 
The solar loop has the advantage of transferring water from the storage 
tank to the collector by means of a water pump, which is controlled by a 
differential thermostat so that the thermostat turns on the pump whenever 
the thermostat's sensors indicate that both the temperature of the panel 
is high enough to add heat to the water tank, and the temperature in the 
tank is not already have a preset level. Also, the pump draws from the 
bottom of the tank and does not have a check valve, which allows water to 
flow back through the pump to drain water back down from the collectors to 
the tank when the pump shuts off. Also, the return line from the 
collectors returns to the top of the storage tank above the water level, 
which has the advantage of an air space in the top to allow for complete 
drainage of the collectors and to allow for thermal expansion. 
The domestic hot water service loop has the advantage of transferring water 
from the bottom of the existing service hot water heater through a heat 
exchanger in the solar heated water storage tank and back to the cold 
water inlet side of the service hot water heater. The circulating pump 
also has the advantage of experiencing very little head pressure, since 
the line is pressurized by city water pressure. The pump for this system 
is also controlled by a differential thermostat, so that the thermostat 
turns on the pump whenever the thermostat's sensors indicate that the 
temperature in the non-pressurized water storage tank is high enough to 
add heat to the pressurized domestic water tank, and the temperature in 
the domestic (city pressure) hot water tank is not above the 
customer-selected maximum. Moreover, this invention has the advantage that 
all city water flows first through the heat exchanger coil so that it 
always may be preheated before entering the domestic hot water tank. 
Additionally, the pump draws the lowest temperature water from the bottom 
of the existing tank, sends it through the water to water heat exchanger, 
and returns it to the "cold water inlet" on the tank. This provides an 
optimum solar heating for domestic hot water use. Still further, the 
temperature setting on the existing hot water unit is set so that it has 
the advantage of providing "back-up hot water" when cloudy days do not 
provide enough solar water. Also, the city water and the non-pressurized 
water never mix. 
During the heating cycle, this invention has the advantage that water is 
drawn from the upper (hottest) portion of the solar storage tank and sent 
through the water to air exchanger and returned to a mid-level area in the 
storage tank. This pump is controlled by a differential thermostat so that 
the thermostat has the advantage of turning on the pump whenever the 
thermostat's sensors indicate that both the temperature in the 
non-pressurized water storage tank is high enough to add heat to the air 
mass in the home, and the temperature in the home is below the customer's 
selected "living area" thermostat setting (the pump only running while 
actively heating living space). Additionally, the blower is activated by 
the thermostat only when there is enough heat in the water to air heat 
exchanger for effective heat transfer. Still further, the recirculating 
pump in the evaporative cooler water pan is controlled by a humidistat set 
to the customer preference, which has the advantage that the heating cycle 
gives the solar assist heating and humidification control for increased 
comfort. 
During the cooling cycle, water is taken from the cooling tower pan and 
sent through the heat exchanger 32, whereupon it is returned to the top of 
the cooling tower. Once again, the recirculating pump and the evaporative 
cooler water pan and the fresh air automatic damper are controlled by 
humidistats set to customer preference and the advantageous embodiments of 
this invention. This two-stage cooling system (conductive and evaporative 
pad) obtains substantially lower output temperatures than conventional 
single-stage evaporative coolers. The first stage, consisting of the 
cooling tower cooled heat exchanger, precools the air and reduces the 
air's wet bulb temperature. The air flow then passes through the 
evaporative pad media, which may be a twelve inch thick media having a 
very high evaporative efficiency without water carry-over, and thus this 
advantage produces much colder air than conventional pads. Additionally, 
the cooling cycle is total and thermostatically controlled to customer 
preference. Accordingly, this invention has the advantage of producing 
lower temperature air than conventional evaporative cooling; and it also 
cycles on and off thermostatically in a way similar to conventional 
refrigerated air conditioning, but with the lower electrical cost of 
evaporative cooling. 
Various modifications within the knowledge of the person skilled in the art 
could be made to the invention without departing from the spirit and scope 
of the same, which are defined in the following claims. For example, while 
the preferred embodiment uses a cooling tower to provide cooling for the 
first heat exchanger, it is possible to use another type of cooler at this 
location in the system, and in this connection, the cooler may be arranged 
on the roof, on the ground, or in some other location. However, it is 
preferable to direct exhaust heat from the heat exchanger 47 in heat 
exchange relationship to recapture waste heat from the cooler 60.