Solar energy collector assembly and method and apparatus for controlling the flow of a transfer medium

A solar energy collector assembly is disclosed. The collector assembly includes an outer enclosure which has a light transparent major face adapted to face a light source and a plurality of walls extending rearwardly from the major face. A single collector plate is secured in the enclosure spaced from and rearward of the major face. The collector plate has a curvilinear configuration with a large radius of curvature. The collector plate has an outer surface adapted to face a light source and an opposite inner surface. A rear panel assembly which has an inner and an outer surface is attached in the enclosure rearward of the collector plate. A heating chamber is formed between the inner surface of the rear panel assembly and the inner surface of the collector plate. An inlet and an outlet communicate with the heating chamber to pass a transfer medium through the heating chamber. A control device is provided for controlling the rate at which a transfer medium is passed through the heating chamber.

BACKGROUND OF THE INVENTION 
The present invention relates broadly to the use of solar energy for 
heating a building, such as a home. More specifically, the present 
invention relates to a solar collector assembly for absorbing solar energy 
and transferring the absorbed energy as heat to the interior of building. 
Numerous types of solar collectors are currently on the market. Solar 
collectors generally utilize a collector plate or collector medium which 
absorbs solar energy. Thereafter some transfer medium, generally a fluid, 
passes by or in close proximity to the collector plate or collector medium 
to transfer energy in the form of heat away from the collector plate or 
collector medium. The transfer medium either passes the heat energy 
directly into the air of a building or to a storage medium. 
One method of classifying solar collectors is according to the type of 
transfer medium used. One type of solar collector utilizes a liquid, such 
as water, as the transfer medium; and another type of solar collector 
utilizes a gas, generally air, as the transfer medium. When gas is 
utilized as the transfer medium, the air which has been heated by the 
solar collector can be passed either directly into the interior of a 
building to be heated or to a storage medium, such as rocks. 
The following patents are illustrative of various prior art solar 
collectors. 
U.S. Pat. No. 4,043,317 of Scharfman discloses a solar collector wherein 
fluid conduits are disposed above a flat collector plate and in heat 
conductive relation to the plate. The fluid conduits are adapted to 
generally carry water as the transfer medium. 
U.S. Pat. No. 4,059,226 of Atkinson discloses a heat collector and storage 
chamber which is adapted to be mounted adjacent a wall of a building. The 
storage chamber holds a relatively large pile of rocks. A glass front wall 
permits sun rays to impinge upon and heat the rocks. Air, preferably from 
a conventional air furnace, passes through the rocks as the transfer 
medium. 
U.S. Pat. No. 4,054,246 of Johnson discloses a building structure wherein 
the outer surface of the building is utilized as a solar collector. A 
plenum is formed behind the outer walls and a gas is blown through the 
plenum to transfer heat away from the walls. The air transfers the heat to 
subterranean gravel pits which serve as heat storage media. When heat is 
required within the building, heated air is passed from the gravel pits to 
the interior of the building. 
U.S. Pat. No. 4,069,809 of Strand discloses solar heat collecting building 
blocks wherein the blocks themselves serve as solar collectors. 
Passageways are formed through the blocks so that air may be passed 
through the blocks to transfer the collected heat out of the blocks. 
U.S. Pat. No. 4,046,133 of Cook discloses a solar panel assembly wherein a 
plurality of triangular-shaped fins form a collector plate. Air is blown 
directly across the top surface of the collector plate to transfer heat 
therefrom to the interior of a building. 
U.S. Pat. No. 4,068,652 of Worthington discloses a solar collector which 
utilizes a generally flat plate collector. The solar collector is 
ullustrated as either a roof mount or wall mount collector. As a wall 
mount collector, the transfer medium is drawn directly into a room to be 
heated. 
U.S. Pat. Nos. 4,033,324 and 4,054,125 of Eckels disclose the use of 
focusing elements above a collector to direct light thereto. In several 
embodiments, a curved collector plate having a small radius of curvature 
is disclosed. The curved collectors plates generally form a curtain-like 
structure. 
U.S. Pat. Nos. 4,051,832; 4,067,316; and 4,071,016 also disclose solar 
energy collectors or panels. 
SUMMARY OF THE INVENTION 
The present invention relates to a solar energy collector assembly. The 
collector assembly includes an outer enclosure which has a light 
transparent major face adapted to face a light source and a plurality of 
walls extending rearwardly from the major face. A single collector plate 
is secured in the enclosure spaced from and rearward of the major face. 
The collector plate has a curvilinear configuration with a large radius of 
curvature. The collector plate has an outer surface adapted to face a 
light source and an opposite inner surface. A rear panel assembly which 
has an inner and an outer surface is attached in the enclosure rearward of 
the collector plate. A heating chamber is formed between the inner surface 
of the rear panel assembly and the inner surface of the collector plate. 
An inlet and an outlet communicate with the heating chamber to pass a 
transfer medium through the heating chamber. 
In the preferred embodiment, the outer surface of the collector plte is 
embossed and coated or painted flat black. The embossing of the outer 
surface reduces the reflection of light from the collector plate and thus 
enhances the efficiency of the heat absorption by the collector plate. The 
inner surface of both the collector plate and the rear panel assembly are 
reflective. Electromagnetic heat energy which emanates from the inner 
surface of the collector plate thus reflects back and forth within the 
heating chamber. This reflection also enhances the efficiency of the 
collector assembly, since the reflection reduces the absorption and 
reabsorption of the heat energy into other parts of the collector 
assembly. The heat energy is thus readily available to a transfer medium 
passing through the heating chamber. 
Turbulence deflectors are disposed within the heating chamber. The 
turbulence deflectors are aligned generally transverse to the path of a 
transfer medium through the heating chamber. Air, which is generally the 
transfer medium, therefore passes through the heating chamber in a 
turbulent manner. The turbulent passage of the air increases the scrubbing 
effect of the air across the surface of the collector plate and thus 
increases the heat transfer from the collector plate to the moving air. 
Also in the preferred embodiment, the outer enclosure is made of a single 
piece of plastic material and insulative materials are interposed between 
the outer enclosure and the collector plate. 
Various advantages and features of novelty which characterize the invention 
are pointed out with particularity in the claims annexed hereto and 
forming a part hereof. However, for a better understanding of the 
invention, its advantages, and objects attained by its use, reference 
should be had to the drawings which form a further part hereof, and to the 
accompanying descriptive matter, in which there is illustrated and 
described preferred embodiments of the invention.

DETAILED DESCRIPTION OF THE INVENTION 
Referring to the drawings in detail, wherein like numerals indicate like 
elements, there is shown in FIG. 1 a plurality of solar collector 
assemblies in accordance with the present invention designated generally 
as 10. The solar collector assemblies 10 are shown mounted to a generally 
South-facing wall 12 of a building 14. The building 14 may be of any type, 
however, the solar collector assemblies 10 are especially suitable for use 
on residential homes. 
The basic components of the solar collector assemblies 10 include an outer 
enclosure 16, a collector plate 18 and a rear panel assembly or wall 20. 
The outer enclosure 16 is made of a single piece of material, preferably a 
plastic material such as a butyrate cellulose plastic. The outer enclosure 
16 has a major face 22, a pair of side walls 24, 26, a top wall 28, and a 
bottom wall 30. A major portion of the face 22 and portions of the side 
walls 24, 26 are light transparent. The entire top and bottom walls 28, 30 
and trim portions 32 of the face 22 and side walls 24, 26 are painted for 
decorative purposes. The major face 22 is adapted to face a light source, 
i.e., sunlight. 
The rear panel assembly 20 is comprised of a rear panel plate 21, a rear 
insulation panel 50 and a sheet of reflective material 54. The rear panel 
plate 21 is preferably made of a lightweight sheet metal material and has 
a plurality of upstanding walls or edges 36, 38, 40 and 42. An air inlet 
hole 44 and an air outlet hole 46 are formed through a face 48 of the rear 
panel plate 21. The rear insulation panel 50 is received on the inside of 
the face 48 between the walls 36-42. A flange 52 extends inwardly from 
each of the walls 36-42 to secure the rear insulation panel 50 in place. 
The sheet of reflective material 54 covers substantially the entire inner 
surface 55 of the insulation panel 50. The reflective material 54 and the 
insulation panel 50 each has an inlet hole 56, 58 in alignment with the 
air inlet hole 44 and air outlet holes 60, 61 in alignment with the air 
outlet hole 46. 
A longitudinally extending structural beam 62 is supported above the rear 
panel assembly 20 adjacent the side wall 24 and a longitudinally extending 
structural beam 64 is supported above the rear panel assembly 20 adjacent 
the side wall 26. As seen in FIG. 5, the structural beams 62, 64 can take 
on a right-angled cross-sectional configuration. A strip of side 
insulation material 66 is received between the beam 62 and the side wall 
24. A strip of side insulation material 68 is received between the beam 64 
and the side wall 26. The strips of insulation material 66, 68 can be made 
of any suitable thermally insulative material, for example, styrofoam. 
A longitudinally extending retainer strip 70 is supported on the rear panel 
assembly 20 next to the beam 62. A longitudinally extending retainer strip 
72 is supported on the rear panel assembly 20 next to the beam 64. The 
retainer strips 70, 72 each have a generally zig-zag cross-sectional 
configuration. A longitudinal edge 74 of the collector plate 18 is 
received and retained within a valley 76 of the retainer strip 70. An 
opposite longitudinal edge 78 of the collector plate 18 is received and 
retained within a valley 80 of the retainer strip 72. A silicon adhesive 
71 is preferably used to provide a thermal seal between the edges 74, 78 
and the retainer strips 70, 72. 
In the preferred embodiment, an inner glazing or fiberglass sheet 82 is 
also secured within the enclosure by the retainer strips 70, 72. A 
longitudinal edge 84 of the fiberglass sheet 82 is secured within a valley 
86 of the retainer strip 70, and an opposite longitudinal edge 88 is 
secured within a valley 90 of the retainer strip 72. The silicon adhesive 
71 is also used to secure the edges 84, 88 to the retainer strips 70, 72. 
The retainer strips 70, 72 are formed of a thermally insulative material 
and serve as a thermal barrier between the outer enclosure 16 and the 
collector plate 18 and the inner glazing 82. The inner glazing 82 is 
preferably made of a solar fiberglass material. The solar fiberglass 
material serves to transmit light through the inner glazing 82 to the 
collector plate 18 while at the same time preventing reflection of the 
light or heat outwardly from the collector plate 18 to the major face 22. 
The inner glazing 82 thus acts similar to a one-way mirror to prevent the 
loss of heat from the assembly 10. 
A plurality of support or insulation blocks are disposed at the top and 
bottom ends of the assembly 10. A relatively thick top insulation blcok 92 
is inserted between the top edges of the fiberglass sheet 82 and of the 
collector plate 18 and the top wall 28. Similarly, a relatively thick 
bottom insulation block 93 is inserted between the top edges of the 
fiberglass sheet 82 and of the collector 18 and the bottom wall 30. A 
spacer-insulation block 94 is contoured to fit between the rear panel 20 
and the collector plate 18. A spacer-insulation block 96 is contoured to 
fit between the collector plate 18 and the fiberglass sheet 82. A 
spacer-insulation block 98 is contoured to fit between the fiberglass 
sheet 82 and the enclosure 16. The spacer-insulation blocks 94-98 are 
disposed at the top end of the assembly 10 below the insulation block 92. 
A similar set of spacer-insulation blocks 100, 102, 104 are disposed at 
the bottom end of the assembly 10 above the insulation block 93. The inner 
surface of the uppermost spacer-insulation blocks 98 and 104 is covered 
with a light-reflective material 106. The inner surface of the central 
space-insulation blocks 96 and 102 is also covered with a light-reflective 
material 107. Light striking the light-reflective material 106, 107 may 
thus be reflected downwardly to the collector plate 18. 
There is illustrated at FIG. 8 an alternate embodiment of the retainer 
strip 72, together with associated altered parts. The retainer strip 70 
and associated parts are similarly altered, however, for simplicity only 
one side of the alternate embodiment is shown in FIG. 8. Similar parts 
will be indicated by similar primed numbers, together with a description 
of their distinction from the first embodiment. The retainer 72' has an 
elongated top section 150 which extends above substantially the entire 
width of the top of the insulation material 68'. A bottom section 152 of 
the retainer strip 72' extends over the reflective surface 54' a longer 
distance than does the bottom section of the retainer strip 72. The 
structural beam 64' is formed as a single planar plate rather than the 
angled configuration of the structural beam 64. The insulation material 
68' extends between the top section 150 and the rear panel plate 21'. The 
upstanding wall 38' of the rear panel assembly 20' extends upwardly along 
the insulation material 68' and the flange 52' of the rear panel assembly 
20' extends inwardly above the top section 150. 
A protective lip 154 is received about the lowermost edge of the side wall 
26'. The protective lip 154 is secured to the upstanding wall 38' by any 
suitable fastening means, such as screws 156. The outer enclosure 16' is 
secured to the remainder of the assembly 10' by means of a plurality of 
screws and washers 158. 
The collector plate 18 has an outer or light-facing surface 108 and an 
inner surface 110. The collector plate 18 has a curvilinear configuration 
in cross-section. The radius of curvature of the curvalinear section is 
relatively large. For example, in a typical assembly 10 which is 
approximately 30 inches in width, approximately 6 feet 8 inches in length, 
and approximately 7 inches in depth, the radius of curvature may be 
between 20-30 inches and preferably is 26 inches. The use of a curvilinear 
collector plate 18 with a large radius of curvature has an advantage over 
a flat collector plate in that throughout the day a larger surface area of 
the collector plate 18 receives a larger normal component of sunlight. If 
a flat collector plate were used, during the morning and evening hours a 
small normal component of sunlight would strike the reflector. By 
utilizing a slightly curved collector plate 18, a larger component of the 
light strikes the collector plate 18 at or near a normal angle during the 
morning and evening hours. 
The collector plate 18 is made of a heat-conductive material such as 
aluminum. As is conventional with solar collector plates, the outer 
surface 108 of the collector plate 18 is coated or painted flat black. A 
flat black surface normally reflects little light, however, in order to 
reduce even more the reflectance of light from the surface 108, the 
surface 108 is embossed. In the preferred embodiment, standard embossed or 
milled sheet metal aluminum is used for the collector plate 18. To further 
enhance the embossing or roughness of the surface 108, the flat black 
paint which is applied to the surface 108 is sprayed on in such a manner 
that some of the paint solidifies into small particles prior to settling 
upon the surface 108. Such a spraying technique further enhances the 
embossing or roughening of the surface 108. 
The inner surface 110 of the collector plate 18 is made of a reflective 
surface. A reflective material 112 is attached to the inner surface of the 
insulation blocks 94, 100. As was mentioned above, the sheet of reflective 
material 54 covers the rear insulation panel 50. A heating chamber 114 is 
thus bounded by the reflective surfaces 54, 112, and 110. Solar energy is 
absorbed by the collector plate 18 and converted into heat energy which 
raises the temperature of the collector 18 and can be emitted into the 
heating chamber 114 as electromagnetic heat energy. The reflective 
surfaces reflect the electromagnetic heat energy which is emitted from the 
inner surface 110 of the collector plate 18. The reflection of the heat 
energy within the cavity 114 enhances the efficiency of the collector 
panel assembly 10 by preventing the reabsorption or absorption of the heat 
into the other parts of the assembly 10. That is, the heat energy remains 
available within the chamber 114 for removal by a transfer medium. 
A plurality of flanges or angle brackets 116 are secured to the inner 
surface 110 of the collector plate 18 and extend into the heating chamber 
114. The flanges 116 each have first sections 118 which run generally 
parallel to the longitudinal dimension of the collector plate 18. Since 
the air flow through the heating chamber 114 is from the air inlet hole 44 
to the air outlet hole 46, the air flows through the heating chamber 
generally in the longitudinal dimension of the collector plate 18. The 
first sections 118 of the flanges 116 are thus generally parallel to the 
direction of the air flow. The flanges 116 have a plurality of cut-out 
sections 120 which are bent away from the first sections 118 and are 
disposed generally transverse or perpendicular to the first sections 118. 
As is best seen in FIG. 6, successive cut-out sections 120 on a given 
flange 116 extend transversely from the first sections 118 in opposite 
directions. The cut-out sections 120 serve as turbulence deflectors to 
create turbulence in the air flowing through the chamber 114. The 
turbulence created by the cut-out sections 120 also enhances the 
efficiency of the assembly 10 by causing a greater scrubbing action 
against the collector plate 18 so that more heat is removed or drawn from 
the collector plate 18. 
The solar energy collector assembly 10 is secured to the wall 12 by a 
plurality of angle brackets 122. The angle brackets 122 are secured to the 
side walls 24, 26 by a suitable means, such as screws 124. As best seen in 
FIGS. 2, 3 and 7, the angle brackets 122 are secured to the wall 12 in 
such a manner that the outer face of the rear panel 20 is spaced from the 
wall 12. 
An air inlet duct 126 is received within the air inlet holes 44, 56, 58 and 
couples the heating chamber 114 with the interior of the building 14. An 
air outlet duct 127 passes through the air outlet holes 46, 54, 61 and 
couples the heating chamber 114 with the interior of the building 14. A 
resilient material 129 surrounds each of the ducts 126, 127. The resilient 
material 129 in its uncompressed state is wider than the space between the 
rear panel 20 and the wall 12. When the brackets 122 are tightened against 
the wall 12, the resilient material 129 compresses and forms an air tight 
seal around the ducts 126, 127. An air-deflecting grille 128 is secured to 
an inner wall 130 of the building 14 and communicates with the air outlet 
duct 127. An air-deflecting grille 132 is also connected to the inner wall 
130 and communicates with the air inlet 126. 
A blower means 134, such as a squirrel cage fan, is supported within the 
air outlet duct 127. The blower means 134 draws air from within the 
building 14 in through the air inlet duct 126, through the heating chamber 
114 and returns the air to the interior of the building 14 through the air 
outlet duct 127. An electrical cord 136 from the blower means 134 is 
passed through the heating chamber 114 and the air inlet duct 126 to the 
interior of the building 14. Thus, the blower means 134 may be connected 
to a typical wall outlet. 
A damper assembly 131 is supported within the air inlet duct 126. As is 
best seen in FIG. 7, the damper assembly 131 includes an upper bracket 
seal 133 and a lower bracket seal 135. A damper door 137 is pivotally 
supported in the inlet duct 126 by a pivot bar 139. The damper door 137 is 
shown in a closed or sealed position in full line and in an open position 
in dotted line. The damper door 137 has a larger surface area below the 
pivot bar 139 and is gravity-biased downwardly to a sealed position. When 
the blower means 134 is operative, only a slight pressure upon the lower 
surface of the damper door 137 will pivot the damper door 137 to its open 
position. The electrical cord 136 may be passed through a grommet 141 in 
the upper bracket seal 133. 
The solar energy collector assembly operates in the following manner. As 
sunlight strikes the collector plate 18, the temperature of the collector 
plate 18 is elevated. Electromagnetic heat energy is given off at the 
inner surface 110 of the collector plate 18 and is reflected within the 
heating chamber 114. The blower means 134 is driven by an electrical motor 
133 and draws air through the heating chamber 114 to transfer the hot air 
from the heating chamber 114 and from the collector plate 18 to the 
interior of the building 14. A control means is provided for controlling 
the operation of the blower means 134. The control means is comprised of a 
pair of temperature-sensitive control sensors or switches 138, 140. The 
temperature-sensitive control switches 138 and 140 are mounted to the 
inner surface 110 of the collector plate 18. The first switch 138 turns 
the blower means 134 on when the collector plate 18 temperature reaches 
approximately 110.degree. F., and thereafter shuts the blower means 134 
off when the temperature of the collector plate 18 falls below 
approximately 90.degree. F. The first switch 138 operates the blower means 
134 through a transformer or resistor 141 at a reduced output. The second 
switch 140 overrides the first switch 138 when the temperature of the 
collector plate 18 reaches approximately 140.degree. F., and continues to 
override the first switch 138 until the temperature of the collector plate 
18 falls to approximately 120.degree. F. While the second switch 140 
overrides the first switch 138, the resistor 141 is shunted and power is 
supplied directly to the blower means 134 so that it operates at its 
normal total output. The connection between the temperature-sensitive 
switches 138, 140, the resistor 141 and the motor 133 is shown 
schematically in FIG. 9. FIG. 10 illustrates that additional 
temperature-sensitive switches 140' and resistors 141' can be added to the 
circuit to provide further incremental control. While only one additional 
pair of switches 140' and 141' are shown in FIG. 10, it should be 
understood that additional pairs of switches and resistors could be 
utilized to attain further incremental control. It has been found that a 
squirrel cage-type blower fan operable at a full output of 100 cubic feet 
per minute and a lower reduced output of 60 cubic feet per minute is 
desirable. In this manner, a substantially constant amount of heat is 
transferred into the interior of the building. 
As shown in FIG. 1, the solar energy collector assemblies 10 are preferably 
installed on the vertical wall of a building. However, the solar energy 
collector assemblies of the present invention may also be mounted to a 
roof of a building. Also, while two solar collector assemblies 10 are 
shown in full line attached to the wall 12, it should be understood that 
any number, i.e., one or more, may be utilized. The number of assemblies 
10 which are utilized will be dependent upon the size of the building to 
be heated and the amount by which the existing heating system is to be 
supplemented by the collector assemblies 10. While the control mechanism 
for the motor 133 has been shown controlling an air blower, it should be 
understood that the control mechanism can be used to control a pump motor 
where a liquid is used as the heat transfer media. 
Numerous characteristics and advantages of the invention have been set 
forth in the foregoing description, together with details of the structure 
and function of the invention, and the novel features thereof are pointed 
out in the appended claims. The disclosure, however, is illustrative only, 
and changes may be made in detail, especially in matters of shape, size, 
and arrangement of parts, within the principle of the invention, to the 
full extent extended by the broad general meaning of the terms in which 
the appended claims are expressed.