Multi-mode solar heating and cooling system

A multi-mode solar heating and cooling system including a solar collector/heat exchanger unit for heating air and/or liquid has an air compartment through which air from a point of use is circulated, and has a liquid compartment through which liquid is circulated from a liquid storage tank. An evaporator unit for chilling air and liquid by evaporation has an air moving device for selectively supplying chilled air directly to the point of use of diverting that air, and is connected to the liquid storage tank for chilling of the liquid therein. Thus, the liquid from the tank may be selectively circulated through the evaporator unit or through the solar collector/heat exchanger unit for appropriate heating or chilling of the liquid which may be simultaneously or subsequently employed for treating the air circulating through the solar collector/heat exchanger unit. Auxiliary heating and cooling coils are provided within the storage tank for standby heating or chilling of the liquid by utilization of suitable conventional heating and cooling devices, and the system is provided with retractable panels for covering the solar collector/heat exchanger unit during different operating modes. The system may also include a solar reflector device for enhancing the solar collecting efficiency of the system and may further include apparatus for selectively supplying untreated fresh air to the premises.

BACKGROUND OF THE INVENTION 
The present invention relates to solar heating and cooling systems, and 
more particularly to a solar heating and cooling system having multiple 
operating modes. 
Due to the energy crises presently existing and the increase in the price 
of fuel, the attention of engineers, inventors, and other has been 
directed to the utilization of alternate sources of energy such as solar 
heating and cooling systems. Solar collectors and heat exchanger units are 
the very heart of any solar heating and cooling system. If such an 
apparatus is to be mounted on the roof of a building, and particularly on 
a home, there are space limitations which must be considered. Thus, if the 
installation is too bulky and occupies an excessive amount of space on the 
roof, it will not be acceptable to the public. If the units are especially 
massive or heavy, they are not susceptible of installation on presently 
existing buildings without making major structural changes to the 
buildings. The apparatus which is installed on a roof should be of compact 
thickness and occupy as small an area as possible to avoid an unsightly 
appearance. 
Further, solar heating and cooling systems should be capable of various 
modes of operation to take advantage of various heating and cooling 
energies when those energies are readily available, and should further be 
capable of supplying different types of conditioned air when appropriate. 
Solar heating and cooling systems now available to the public are very 
expensive from both construction and installation standpoints, with the 
total costs being excessively high so as to discourage their acceptance. 
The present invention is founded on the belief that the system of this 
invention may be manufactured and installed at a price which will be 
acceptable to many of the people who cannot now afford the existing solar 
heating and cooling systems. In addition, the operational costs will be a 
fraction of that of the conventional heating and cooling systems. One of 
the outstanding features of the instant system is that it may be installed 
in most existing building structures with minimal alterations thereof and 
without disrupting the present heating and/or cooling systems. The system 
of the present invention does not require that a new building or home be 
constructed to accommodate it, thus making this system readily available 
to the public. 
Conventional heating and cooling systems, and many of the known solar 
heating and cooling systems are notably lacking in means for the storage 
of thermal energy and thus are forced to operate on what may be called a 
demand basis, and such techniques result in wasted and inefficient 
utilization thereof. 
The problems resulting from the demand basis technique may be placed in 
three major problem areas with the first being demand timing, the second 
being the intermittent delivery, and the third problem being the 
fluctuating amounts of energy that must be supplied to satisfy the demand. 
To explain the term `demand basis`, consider a home which is either too hot 
or too cold, that fact is sensed by a thermostat which actuates the 
appropriate equipment and when that demand has been satisfied, the 
equipment is shut down. 
With regard to the first problem area defined above as `demand timing`, the 
demand for heating and/or cooling invariably occurs at times when those 
tasks are most inefficiently accomplished. For example, it is well known 
that a heat pump is an efficient mechanism, however, the demand basis 
under which a heat pump is forced to operate substantially reduces the 
efficiency of that equipment. During a heating cycle, the heat pump will 
extract heat from the atmosphere and direct it to the zone being heated. 
The demand for heat in the zone is the greatest when the temperature is 
low and the atmosphere contains a relatively small amount of readily 
available heat. Due to this lack of readily available heat, during the 
peak demand time, the heat pump must work hard to accomplish the task 
being asked of it. The same basic inefficiency results during a cooling 
cycle of the heat pump due to the heat extracted from the zone being 
dissipated into the atmosphere that already contains a relatively large 
quantity of heat. Thus, to accomplish satisfactory operation under these 
conditions, the equipment must be relatively large to compensate for 
inefficient operation resulting from demand timing and it is readily 
apparent that operating the equipment inefficiently results in the 
consumption of power at a rate which is excessive for the amount of work 
being accomplished. 
In regard to the second problem defined above as `intermittent delivery`, 
consider a zone being heated with the thermostat being set at 70.degree.. 
Due to intermittent delivery, the temperature in the zone will vary in a 
range of from about 67.degree. to 74.degree.. When the temperature in the 
zone falls to about 67.degree., the heating equipment is started and will 
continue to operate until the zone temperature reaches about 74.degree. at 
which time the equipment is shut off. The temperature will then drop until 
the 67.degree. level is reached again and the heating cycle is repeated 
again. This temperature drop is non-linear due to the varying heat loss at 
the different temperatures, with the heat loss being considerably greater 
at 74.degree. than at the lower temperatures. It is well known that the 
heat loss through walls, ceilings, windows, and the like, is determined by 
the temperature differential on opposite sides thereof. Thus, the 
temperature drop from 74.degree. to 70.degree. will be relatively rapid 
and it will slow down in the drop from 70.degree. to 67.degree.. The zone 
will therefore fluctuate in temperature and will be below the desired 
70.degree. level the greatest percentage of the time. It will be obvious 
that the exact opposite temperature fluctuations will occur when a zone is 
being cooled. Such temperature fluctuations in conjunction with the 
duration of the undesirable temperatures results in discomfort often 
resulting in upward or downward adjustments of the thermostat. Such 
discomfort is but one drawback of an intermittent delivery system with 
other drawbacks being the relatively high power consumption and the heat 
loss or gain of such a system when compared with one of constant delivery. 
The power consumed in repeatedly starting and stopping equipment is well 
known to be greater than the power consumed in continuous operation 
thereof. Also, repeated actuation of such equipment to raise or lower the 
temperature utilizes more energy than constantly deliverying constant 
properly conditioned air to maintain the desired temperature. By 
maintaining a constant confortable temperature, the increased heat loss or 
gain which occurs at fluctuating temperatures is avoided. 
The third problem area relating to the fluctuating amounts of energy 
supplied to satisfy the demand basis technique will be easily understood 
upon consideration of the hereinbefore described examples relating to 
heating and cooling. It has been established that the demand for heating 
and cooling is the greatest when it is most difficult to accomplish those 
tasks. Those demands, plus other energy consuming habits of the consumers, 
cause tremendous fluctuation of the energy consumption to occur over a 
given period of time. For example, in hot weather, electric power 
generating facilities will be operating at or near capacity from 
approximately 3:00 P.M. to 8:00 P.M. and will be operating considerably 
below capacity at other times of the day. Such inconsistent energy demands 
cause problems for the utility companies and such problems result in 
higher rates for the consumer as well as possible energy curtailments. 
Briefly, the fluctuating energy consumption as described above results in 
problems for the utility companies in that their ability to meet the 
demand during peak demand periods is constantly reduced as the demand for 
energy increases. Until recently, this presented no problems in that when 
the demand went up the utilities simply acquired more fuel for the 
production of energy or built more power generating facilities. Such 
solutions are no longer a simple matter due to environmental 
considerations, availability of fuel to distribute to consumers or to 
operate generating equipment, the greatly increased cost of building 
facilities, and the like. 
OBJECTS OF THE INVENTION 
With the foregoing conditions and problems in mind, the present invention 
has in view the following objects: 
1. To provide an efficient solar heating and cooling system in which the 
main sources of energy are solar heating and evaporative cooling. 
2. To provide a system of the above noted type in which a liquid may be 
heated or chilled, for storage, recycling and for treating air in a 
premises. 
3. To provide, in a solar heating and cooling system of the character 
aforesaid, evaporator means which is employed for the direct cooling of 
air and for chilling a liquid which is storable for subsequent use and/or 
simultaneously usable for indirect cooling of air. 
4. To provide, in a solar heating and cooling system of the type noted, a 
solar collector for heating air and/or a liquid with that liquid being 
storable for subsequent use in heating of air. 
5. To provide, in a solar heating and cooling system of the type aforesaid, 
means for utilizing auxiliary heating devices for standby heating during 
periods of insufficient solar activity. 
6. To provide, in a solar heating and cooling system of the character 
aforesaid, means for utilizing auxiliary cooling devices for standby 
cooling when evaporative cooling is inefficient. 
7. To provide, in a solar heating and cooling system of the character 
aforesaid, means for delivering fresh untreated air. 
8. To provide, in a solar heating and cooling system of the character 
aforesaid, an arrangement of elements which allows the liquid in the 
system to drain into an underground tank by gravity within a short period 
of time to prevent freezing in cold weather. 
9. To provide, in a solar heating and cooling system of the type noted, a 
solar collector/heat exchanger for heating, by radiation and convection, 
the air circulating therethrough to and from a premises. 
10. To provide, in a solar heating and cooling system of the above 
described character, a solar collector/heat exchanger for heating liquids 
in the system for subsequent use in the heat exchanger for indirectly 
heating air circulatable therethrough to and from a premises. 
11. To provide, in a solar heating and cooling system of the above 
described type, a solar collector/heat exchanger which when covered and 
has chilled liquid circulating therethrough, functions as a heat exchanger 
for indirectly cooling air circulatable therethrough to and from a 
premises. 
12. To provide, in a solar heating and cooling system of the hereinbefore 
noted type, a solar collector/heat exchanger unit, a retractable cover 
therefor, a solar radiation reflector, an evaporator unit, and an 
underground liquid storage tank, all of which cooperate to function 
efficiently for constant delivery of air to a premises by means of plural 
operating modes. 
Various other and more detailed objects and advantages of the invention, 
such as arise in connection with carrying out the above ides in a 
practical embodiment will in part become apparent, and in part 
hereinafter, be stated as the description of this invention proceeds. 
SUMMARY OF THE INVENTION 
The foregoing and other objects of the invention are accomplished by 
providing a multi-mode solar heating and cooling system, the 
characteristic and essential elements of which include: a solar 
collector/heat exchanger unit having retractable cover panels, a solar 
radiation reflector, a liquid storage tank, and an evaporator unit which 
are interconnected by and operate in conjunction with suitable plumbing, 
ducts, liquid and air moving devices and other mechanisms as will 
hereinafter be described in detail. 
The solar collector/heat exchanger is enclosed within a suitably insulated 
frame or enclosure and includes an air compartment formed of a plurality 
of longitudinally extending channels having a manifold at each of the 
opposite ends thereof which are in communication with all of those 
channels. A liquid compartment is provided immediately above the air 
compartment and in contiguous engagement therewith for transferring 
thermal energy therebetween. The liquid compartment includes spaced flat 
metallic sheets between which sheeted liquid flows from a perforated feed 
pipe to an oppositely positioned liquid collecting trough. The flat 
metallic sheets are suitably treated so as to act as a solar radiation 
absorbing panel, and the entire liquid compartment is spacedly disposed 
below a solar window heat trap formed by a spaced pair of transparent 
sheets. 
The solar collector/heat exchanger unit is provided with retractable cover 
panels which allow the unit to be exposed during periods of solar 
radiation activity and to be covered during inactive periods to prevent 
heat loss by re-radiation. In addition, the cover panels will block solar 
radiation impingement upon the solar collector/heat exchanger when chilled 
liquid is circulating therethrough for indirect cooling of air. 
It is preferred, that the solar collecting function of the solar 
collector/heat exchanger unit be enhanced by a reflector device which 
increases the amount of solar radiation impinging thereon. 
Heating of the liquid within the solar heating and cooling system of the 
present invention is accomplished by the liquid, preferrably water, being 
directed from the storage tank through an inlet pipeline having a pump 
therein, to the perforated feed pipe of the liquid compartment of the 
solar collector/heat exchanger unit. After passage of the water through 
the spaced metallic sheets, the heated water is collected in the trough 
and returned to the storage tank by a return pipeline. Chilling of the 
liquid in the solar heating and cooling system is accomplished by 
directing water from the storage tank to an evaporator unit in the form of 
a cooling tower, evaporative cooler, or similar device and when the water 
supplied thereto is chilled by evaporation, it is returned to the storage 
tank. 
Thus, the liquid in the solar heating and cooling system as described above 
may be heated and chilled in accordance with the desired seasonal 
requirements, and may be employed in the solar collector/heat exchanger to 
indirectly condition the air of the premises. Such indirect conditioning 
of the air is accomplished by supplying the air from a premises to be 
heated or cooled through the supply duct, having an air moving blower 
therein, to one of the manifolds of the air compartment of the solar 
collector/heat exchanger unit. After passage of that supplied air through 
the plurality of channels, the exiting air is returned to the premises by 
means of a return duct connected to the other manifold of the air 
compartment. 
In addition to the wear chilling function of the evaporator unit, that unit 
is provided with means for drawing ambient air therethrough for chilling 
thereof on its way into the premises, thus providing the system of the 
present invention with direct evaporative cooling capabilities. 
An alternate method of heating the air in a premises may be employed 
wherein air from the premises is circulated through the uncovered solar 
collector/heat exchanger unit from which the liquid has been removed. In 
such a case thermal energy impinging upon the solar collector is 
transmitted by radiation and conduction to the air circulating through the 
heat exchanger. 
In addition to the above described primary sources of energy for heating 
and cooling the liquids, the system of the present invention may be 
provided with auxiliary or backup energy devices for heating and cooling 
of the liquid therein. Such backup systems operate on a standby basis for 
heating and cooling purposes during periods of insufficient solar 
radiation and during periods when the evaporator unit is incapable of 
effective evaporative cooling. The backup energy system may include a 
heating coil and cooling coil located within the storage tank, so that 
conventional devices for heating and cooling of the liquid may be employed 
when necessary. Such conventional sources may include a heat pump, a 
refrigeration unit, electric or gas heating unit, or any of several other 
well known devices. 
In addition to the previously described functions of the solar heating and 
cooling system of the present invention, the system may also be provided 
with means for circulating fresh ambient air through the premises when the 
temperature and humidity of that ambient air makes the heating or cooling 
thereof unnecessary. 
For a full and more complete understanding of the solar heating and cooling 
system of the present invention, reference is made to the following 
description and accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring more particularly to the drawings, FIG. 1 shows the multi-mode 
solar heating and cooling system of the present invention which is 
indicated generally by the reference numeral 10. As shown, the system 10 
is mounted on and connected to a suitable building 11 having the usual 
side walls 12 (one shown), inclined roof 13, with a ceiling structure 14 
spaced from the roof to provide an attic space 15. 
As shown in FIG. 1, and as will hereinafter be described in detail, the 
main components or elements of the system 10 are a solar collector/heat 
exchanger unit 16, a retractable cover panel assembly 18, a solar 
radiation reflector mechanism 20, an evaporator means 22, and a liquid 
storage tank 24. Those main elements are provided with subsystems and 
interconnecting components which will be described as this description 
progresses. 
The solar collector/heat exchanger unit 16 is a multi-purpose mechanism and 
as seen in FIGS. 1, 2, 3, 4, and 5, is preferrably of rectangular box 
shaped configuration providing an enclosure having a bottom 25, 
longitudinally extending side walls 26 and end walls 27, with the 
extending edges of the side and end walls, 26 and 27, respectively, being 
formed with flanges 28 which define an opening in the box shaped 
enclosure. The side and end walls 26 and 27 are covered on their outwardly 
disposed surfaces with suitable insulative material 29. 
Positioned within the box shaped enclosure of the unit 16 adjacent the 
bottom 25 thereof is an air compartment which comprises a plurality of 
longitudinally extending channel members 30 which are arranged parallel 
with respect to each other to form a plurality of air passages 31. At one 
end of the channels adjacent one of the end walls 27, an air inlet 
manifold 32 is provided which extends transversely with respect to those 
channels and is in communication with the passages 31. Similarly, a 
transverse air outlet manifold 33 is provided at the opposite ends of the 
channels 30 and is in communication with the opposite ends of the air 
passages 31. As will hereinafter be described in detail, the bottom 25 of 
the housing is formed with a normally extending inlet duct 34 immediately 
below and in communication with the air inlet manifold 32 and is formed 
with a similar outlet duct 35 immediately below and in communication with 
the outlet manifold 33. 
As shown in FIG. 1, when the solar collector/heat exchanger unit 16 is 
mounted on the roof 13 of the building 11, the inlet duct 34 and outlet 
duct 35 extend through the roof into the attic 15 and are suitably coupled 
to air supply duct 36 and an air return duct 37. The air supply duct 36 
communicates on its opposite end with the outlet of a suitable blower 38, 
with the inlet of that blower coupled to an air directing device 39 which, 
as will be described, allows air to be drawn into the blower 38 either 
from within the building 11 or from ambient by means of a fresh air duct 
40. The air return duct 37 extends downwardly from the outlet duct 35 
through the ceiling of the building 11 so as to be in communication with 
the interior thereof. Thus, it may now be seen that air may be circulated 
through the air compartment of the solar collector/heat exchanger unit 16 
either from and to the interior of the building 11, or from ambient to the 
interior of the building. 
Referring again to FIGS. 4 and 5, the solar collector/heat exchanger unit 
16 is seen to include a liquid compartment immediately above and in 
contiguous engagement with the previously described air compartment. The 
liquid compartment includes a bottom flat metallic sheet 42 in contiguous 
engagement with the channels 30 of the air compartment, and an upper flat 
metallic sheet 44 which is spaced from and parallel with respect to the 
bottom sheet 42. The spacing and parallelisms of the sheets 42 and 44 is 
maintained by a plurality of spacers 45 interposed therebetween at various 
locations. The longitudinal edges of the sheets 42 and 44 are sealed by 
any suitable means at 46 (FIG. 5) so as to be watertight. The aligned end 
edges of the metallic sheets 42 and 44 which are adjacent the inlet air 
manifold 32 are open along the length of those edges and a perforated feed 
pipe 47 is sealingly affixed so that the perforations thereof communicate 
with the space between the sheets. The feed pipe 47 is supplied with 
liquid by means of an inlet pipe 48 suitably affixed thereto as will be 
hereinafter described. The opposite side edges of the sheets 42 and 44 are 
also open along their entire length so that the space between the sheets 
is in communication with a liquid trough 49 and is provided with a drain 
pipe 50 which extends therefrom exteriorly of the solar collector/heat 
exchanger unit 16. In operation, liquid is jetted, or sprayed, under 
pressure from the feed pipe 47 and will form a thin film, or sheet, of 
liquid which flows by gravity between the metallic sheets 42 and 44 and is 
collected in the liquid trough 49. 
In parallel relationship with respect to the metallic sheets 42 and 44 and 
disposed so as to be spaced thereabove, a solar window heat trap 52 is 
provided which serves as a solar window for solar radiation impinging 
thereon, and due to what is commonly referred to as the `greenhouse 
effect`, will prevent the escape of most of the radiation. While the solar 
window heat trap may take any of several well known forms, such as spaced 
double glazed glass, the preferred construction includes a pair of spaced 
transparent, or semi-transparent, sheets 53 of pre-stretched suitable 
plastic material such as that marketed under the trade name `Tedlar`. The 
transparent sheets 53 are pre-stretched on a suitable frame 54, such as of 
wood, and that assembly is suitably demountably affixed in sealed 
engagement with the interior surfaces of the side and end walls 26 and 27 
of the solar collector/heat exchanger unit 16. 
It should be noted that at least the upwardly disposed surfaces of the 
metallic sheets 42 and 44 are suitably treated, such as by blackening 
thereof, so that those sheets will serve as solar radiation absorbing 
panels and will thus be heated when solar energy impinges thereon through 
the solar window heat trap 52. 
As hereinbefore mentioned, the solar heating and cooling system further 
includes a retractable cover panel assembly 18 which is seen best in FIGS. 
2 and 3. 
Before proceeding with the detailed description of the cover assembly 18, 
it is deemed appropriate to note that although the description thus far 
has referred to only one solar collector/heat exchanger unit 16, it will 
be appreciated that a plurality of such units may be employed as dictated 
by system requirements, as is well known in the industry. Thus, for 
completeness of this disclosure, FIGS. 2 and 3 illustrate a pair of the 
solar collector/heat exchanger units which are designated in their 
entirety by the numerals 16 and 16a. 
The retractable cover panel assembly 18 is therefore shown to be configured 
for operation with the two solar collector/heat exchanger units 16 and 
16a, and it will be understood that the assembly 18 may be configured to 
handle a single or multiplicity of such units. 
In the case illustrated, the panel assembly 18 includes a pair of cover 
panels 56 and 56a which are each sized to have approximately the same 
length and width dimensions as the solar collector/heat exchanger units 16 
and 16a, and are laterally spaced apart a distance approximately equal to 
the width dimension of the units 16 and 16a. The panels 56 and 56a are 
preferably fabricated of insulative material 57 such as polyurethane which 
is encased in a suitable skin 58 such as of metal. The aligned end walls 
of the panels 56 and 56a are interconnected by a pair of elongated bars 59 
and 60, affixed such as by bolts 61, to maintain the spaced disposition of 
the panels so that they will move in unison. The bars 59 and 60 are each 
provided with an extending end 62 having suitable teeth 63 formed thereon 
so that the ends serve as racks which are engaged by pinion gears 64. The 
pinion gears 64 are mounted for rotation on the opposite ends of a drive 
shaft 65 which is driven through reduction gears 66 by a reversible drive 
motor 67. The bars 59 and 60 are supported on appropriate roller wheels 68 
affixed to the roof 13 so that upon actuation of the motor 67, the panels 
will move from the open position shown to a position which completely 
covers the solar collector/heat exchanger units 16 and 16a. 
The solar radiation reflector mechanism 20, as shown in FIG. 1, includes a 
reflector panel 69 which is mounted on the roof 13 such as by a hinge 70 
and is adjustably supported in various angular positions with respect to 
the roof by side braces 71 (one shown). The reflector 20 is employed to 
enhance the operation of the solar collector/heat exchanger unit 16 by 
directing reflected solar rays thereon in addition to the directly 
impinging solar rays. Although the reflector mechanism is disclosed as 
being manually adjustable, it will be obvious that such adjustment could 
be made automatically by equipping the mechanism with any of several well 
known devices such as a light sensing diode (not shown) which activates 
suitable positioning equipment (not shown). 
The inlet pipe 48 of the solar collector/heat exchanger unit 16 is coupled 
as shown in FIG. 1, to a liquid supply line 74 which extends downwardly 
from the unit 16 through a shutoff valve 75, through a T-fitting 76 to the 
outlet 77 of pump 78 mounted such as on the ground 79 adjacent the 
building 11. The inlet 80 of the pump 78 is connected by a pipeline 81 to 
the liquid storage tank 24. The T-fitting 76 provided in the liquid supply 
line 74, has a pipe 82 connected thereto which has a shutoff valve 83 
therein and which is connected on its opposite end to the evaporator means 
22. 
The drain pipe 50 of the solar collector/heat exchanger unit 16 is coupled 
by a liquid return line 84 to the underground liquid storage tank 24. 
Thus, it will be seen that the liquid 86, preferrably water, within the 
storage tank 24 may be directed by pump 78 to the inlet side of the solar 
collector/heat exchanger unit 16, and after passage therethrough, the 
liquid will be returned to the tank 24. Further, the liquid 86 may be 
directed through pipe 82 and valve 83 to the evaporator means 22. 
The evaporator means 22 may be any well known device which utilizes the 
principle of cooling by evaporation. Such known devices may be in the form 
of a cooling tower (not shown) or an evaporative cooler 88. The 
evaporative cooler 88, shown for completeness of this disclosure, is of 
the type sometimes referred to in the industry as a `side draft` cooler. 
Briefly, the cooler 88 includes a suitable housing 89 having wettable 
cooler pads 90 (one shown) mounted in the sides thereof. An air moving 
centrifugal blower 91 is mounted within the housing 89, and the blower has 
an axial inlet 92 and a centrifugal outlet 93. The wettable cooler pads 90 
receive water from a distribution manifold 94 mounted above the pads 
adjacent the top of the housing 89, and the water, after passing through 
the pads, is collected, in a sump 95 at the bottom of the housing. As 
shown, the evaporative cooler 88 is mounted over the liquid storage tank 
24 so that water 86 within the sump 95 will drain by gravity through a 
pipeline 96 into the liquid storage tank 24. 
The liquid storage tank 24 may be configured in any suitable shape with the 
size thereof being determined by the storage capacity requirements of the 
particular installation. The tank may be fabricated of any suitable 
material, and is preferrably below the ground and must be well insulated. 
Although the tank 24 is shown as being burried in the ground 79, it could 
just as well be located in a basement (not shown), or otherwise, as long 
as it is below the bottom of the evaporator means 22. The storage tank 24 
is equipped with a suitable make-up water system such as a supply line 97 
leading from a suitable source of water (not shown) with the line 
connected to a float operated shutoff valve 99. 
The storage tank 24 is provided with a pair of auxiliary heat exchangers in 
the form of a heating coil 98 and a cooling coil 100. The heating coil 98 
is submerged in the liquid 86 and may be connected to any of several well 
known heating devices which are indicated by the block 101. Such devices 
may include any device which will heat water by utilizing conventional 
energy forms such as electric, natural gas, steam and the like. The 
cooling coil 100 is also submerged in the liquid 86 of the tank 24 and may 
be connected to any of several well known cooling devices which are 
indicated by the block 102. Such devices may include a refrigeration unit 
(not shown) which is operated by conventional energy forms such as 
electricity or natural gas. 
The heat exchanger coils 98 and 100 and their respective heating and 
cooling devices 101 and 102 are employed as standby or booster mechanisms. 
The heating coil 98 and auxiliary heating device 101 will operate to heat 
the liquid 86 during periods of prolonged solar inactivity and/or to boost 
the liquid temperature when the amount of solar radiation is insufficient 
to heat the liquid to the necessary temperatures. Likewise, the cooling 
coil 100 and its auxiliary cooling device will operate to chill or assist 
in chilling the liquid 86 when the atmospheric conditions are such that 
the evaporator means will not function efficiently such as in periods of 
relatively high humidity. 
It will be appreciated that the above described auxiliary heating and 
cooling devices would not be necessary when the solar heating and cooling 
system 10 of the present invention is installed in a building which has 
existing conventional heating and cooling equipment. However, when 
installed in a new building, the above described auxiliary heating and 
cooling devices may be employed to provide a completely self-sufficient 
solar heating and cooling system and the auxiliary equipment can be of 
relatively small size as compared to a system which utilizes such 
equipment for all the heating and cooling functions. This can be easily 
understood upon consideration of the hereinbefore described problems 
associated with equipment operated on a demand basis as compared to 
equipment which may be operated when it is economically feasible and 
convenient to do so, such as during non-peak load periods. 
OPERATION 
The solar heating and cooling system 10 of the present invention is capable 
of operating in various modes which will now be described in detail. 
During the heating season, with the retractable cover panel assembly 18 in 
the open position and with the reflector mechanism 20 properly adjusted, 
solar radiation, both direct and reflected, will impinge upon the water 
compartment of the solar collector/heat exchanger unit 16. The solar 
radiation will be collected by the water compartment and, in the absence 
of liquid, i.e., pump 78 is not operating, the heat will be transmitted by 
conduction and radiation into the air compartment of the unit 16 to heat 
the air being circulated therethrough to and from the interior of the 
building 11 by means of the blower 38. 
During periods of more moderate temperatures when less heating is required, 
the blower 38 may be turned off and the air flow direction through the 
solar collector/heat exchanger unit 16 will be reversed. Air will be drawn 
into the return duct 37 and will move by thermo-siphonic action through 
the air compartment of the unit 16 and will absorb heat conducted and 
radiated from the water compartment. This heated air will move to the 
upper end of the unit 16 and will emerge through duct 36 into the 
building. Such action will create sufficient draft to cause moderate 
circulation and heating of the air. 
For heating of the air at night or during cloudy conditions, hot water from 
the liquid storage tank 24 is circulated, by means of the pump 78, through 
the solar collector/heat exchanger unit 16, and air moving from the 
building through the unit 16 will absorb heat from the water. Such a 
heating function is preferrably accomplished with the retractable cover 
panel assembly 18 in the closed position to prevent sky radiation and to 
prevent convection losses of the heat into the relatively cooler 
atmosphere. 
The water 86 within the storage tank 24 may be heated and stored during 
periods of solar radiation activity, and such is accomplished by 
circulating the water as described above so that the water will absorb the 
solar heat impinging upon the water compartment of the solar 
collector/heat exchanger unit 16. Continuous circulation, or recycling, of 
the water through the unit 16 during periods of solar activity will 
gradually heat the water until it reaches a temperature approaching that 
of the collector surface 44 of the unit 16, at which time the pump 78 may 
be shut down. When that occurs the water in the system will immediately 
drain by gravity into the tank 24 for storage until needed. 
During the season when cooling is needed, the retractable cover panel 
assembly 18 is in the closed position and chilled water from the storage 
tank 24 is circulated through the water compartment of the solar 
collector/heat exchanger unit 16 to absorb heat from the air being 
circulated therethrough from the interior of the building 11. When the air 
is being heated as previously described, air movement through the unit 16 
is effected by forcing the air to move downwardly through the unit against 
the natural tendency for heated air to rise. When the air is being cooled, 
the draft is increased due to the natural tendency for cold air to fall. 
When the liquid 86 is being chilled for use as described above, the liquid 
is pumped from the storage tank 24 through the supply line 74. With the 
valve 75 closed and the valve 83 open, the liquid will pass through the 
evaporator means 22 where chilling thereof will occur due to evaporation. 
Continued circulation, or recycling, of the liquid through the evaporator 
means 22 will gradually lower the water temperature to where it is 
approaching wet bulb temperature which, in the summertime, is about 
20.degree. to 40.degree. below the ambient temperature. When that 
temperature is reached, the pump 78 is shut down and the chilled liquid is 
stored in the tank 24 for use when needed. 
In the cooling season, the evaporator means 22 is preferrably employed at 
night when the ambient temperature and wet bulb temperature are lower 
which permits the liquid 86 to be chilled to a much lower degree. 
When the water is being chilled as described above, air entering and 
passing through the evaporator means 22, which in the illustrated 
embodiment is the evaporative cooler 88, will be chilled by evaporation 
and directed through the centrifugal outlet duct 93 into an air directing 
device 104 interposed between the evaporator means and the building 11. As 
seen best in FIG. 6, the device 104 as a T-shaped housing 105 with the 
centrifugal outlet duct 93 connected to the inlet port 106 thereof and 
having suitable air delivery duct 107 coupled to the outlet port 108. The 
air delivery duct 107 communicates from the device 104 into the building 
11. The air directing device 104 is also formed with an exhaust port 109 
by which the air from the evaporator means 22 may be optionally exhausted 
to ambient. The selective directing of air is accomplished by a damper 110 
pivotably mounted in the housing 105. The chilled air exiting from the 
evaporator means 22 may be directed into the building 11 as previously 
mentioned for cooling of the interior thereof. That air will achieve a 
very comfortable effective temperature particularly in areas having a 
relatively low humidity. If the air entering the building becomes 
excessively humid, the damper 110 may be switched to cause the humid air 
to be exhausted to ambient. 
Thus, the evaporator means 22 at night serves a dual purpose; namely, the 
chilling of the liquid for storage purposes and the simultaneous chilling 
of air for evaporative or direct cooling of the building. In the daytime 
when ambient temperatures are high, the evaporator is turned off and the 
cold water from storage is circulated through the solar collector/heat 
exchanger unit 16 for indirect cooling of the air as previously described. 
At certain times of the year, such as the spring and fall, the outside 
temperature and relative humidity will be such that no cooling or heating 
of the air will be needed. In such instances, circulation of fresh outside 
air may be accomplished by operating the blower 38 which draws air from 
ambient through the duct 40, through the air directing device 39, through 
the solar collector/heat exchanger unit 16 and through the duct 37 into 
the building. 
As seen in FIG. 7, the air directing device 39 is a T-shaped housing 112 
having a suitable damper or flapper valve, 113 mounted therein for 
movement between positions of closing the inlet port thereto from the 
interior of the building and of closing the inlet port thereto from the 
duct 40. 
During operation of the above described circulation of fresh air, the air 
directing device 104 may be employed as an outlet for the fresh air, 
and/or a window (not shown) may be opened to accomplish or enhance such 
exhausting of the air. Additionally, the centrifugal blower 91 of the 
evaporator means 22 may be employed as means for circulating fresh 
untreated air. Such may be accomplished by not circulating liquid through 
the evaporator means so as not to achieve any evaporative cooling of the 
air moving through the evaporator on its way to the building. 
In addition to the above described operational capabilities of the solar 
heating and cooling system 10 of the present invention, considerable 
cooling of the interior of the building may be accomplished by taking 
advantage of the phenomenon known as nocturnal radiation. To accomplish 
this, the retractable cover panel assembly is moved to the open position 
and air is circulated from the building 11 by means of the blower 38. In 
this manner heat from the circulating air will be radiated to the night 
sky, and such radiation may be enhanced by configuring the heat trap 52 of 
the solar collector/heat exchanger unit 16 so that removal thereof may be 
accomplished. 
While the hereinbefore described solar heating and cooling system 10 
constitutes the preferred embodiment, it is contemplated that many 
installations will be such that installation of this solar collector/heat 
exchanger unit 16 on the roof 13 will not be practical or possible. In 
such cases, a wall mounted solar collector/heat exchanger unit 116 (FIG. 
8) may be employed. The unit 116 is similar to the previously described 
unit 16 with minor modifications of the air chamber portion thereof. In 
the case of the wall mounted solar collector/heat exchanger 116, the air 
inlet manifold 117 is open along its entire length so that air will freely 
move into that manifold 117 and will pass upwardly through the air 
passages 31. That upwardly rising air is collected in the air outlet 
manifold 118 and directed back into the building 11 by an exhaust duct 120 
having a suitable induction draft fan 122 mounted therein. 
It will be understood that a system which includes the above described wall 
mounted solar collector/heat exchanger 116 will include all of the other 
elements and components hereinbefore described with relation to the system 
10 such as the rectractable cover panel assembly 18, solar reflector 20, 
evaporator means 22, storage tank 24, and so forth. The operation of the 
system employing the wall mounted solar collector/heat exchanger unit 116 
will be the same as that previously described for the system 10. In 
addition to the previously noted operations, in the wall mounted solar 
collector/heat exchanger the inwardly disposed wall 124 of the air 
compartment will act as a radiating surface when heating operations are 
being accomplished and will act as a heat absorbing surface when cooling 
functions are being accomplished. Other operational advantages of the wall 
mounted system such as the so-called chimney effect where air movement 
through the solar collector/heat exchanger unit 116 due to 
thermo-siphoning will cause the air to move more rapidly than in the 
angularly disposed roof mounted unit 16. Additionally, the wall mounted 
unit 116 is more readily accessible for maintenance purposes and no air 
moving ducts are required. 
While the principles of the invention have now been made clear in an 
illustrated embodiment, there will be immediately obvious to those skilled 
in the art, many modifications of structure, arrangements, proportions, 
the elements, materials, and components used in the practice of the 
invention, and otherwise, which are particularly adapted for specific 
environments and operation requirements without departing from those 
principles. 
For example, it will be apparent that the various functions of the system, 
such as switching from a heating mode to a cooling mode may be 
accomplished manually as shown and described, however, existing mechanisms 
for sensing, switching and otherwise may be readily adapted to the system. 
Such devices may include humidistats, thermostats, solar radiation sensing 
devices, solenoid switching valves and the like. 
The appended claims are therefore intended to cover and embrace any such 
modifications within the limits only of the true spirit and scope of the 
invention.