Note: Descriptions are shown in the official language in which they were submitted.
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Passive Solar Panel and Construction Member
This invention relates to a passive solar panel which also serves
as a construction member for a building.
Solar energy has been utilized in many applications with various
degrees of sophistication. Some, such as providing domestic hot
water9 are year-round and require special equipment while others
are as simple as opening blinds or drapes to permit the sun load to
help heat a room in the winter. Many such uses have inherent
problems or compromises built into them such as siting and
architectural considerations. Windows, for example, permit the sun
load to reach the interior of a room while the sun is shining from
; a proper direction, but they permit it in summer, also, when it is
not desired. Additionally, windows have greatly reduced insulating
properties when compared to normal building insulation and so
permit a net heat loss due to the presence of windows in the winter
and, similarly, cooling loss in the summer for an air conditioned
house. Offsetting these net heating/cooling losses, are the
psychological advantages of a naturally illuminated room.
In accordance with the present invention, a solar panel is
incorporated into the initial construction of the wall of a
building as a part o a construction member formed by the solar
panel and a rigid foam insulation block so as to replace a portion
of the normal interior and exterior walls and the insulation
therebetween. Enabling/disabling means such as a solenoid valve
tied into the heating and/or cooling thermostat can be used ~o
control when the heating function takes place. Without such a
function, the ambient summer temperature, even in the absence of a
sun load, could be sufficient to vapori~e the refrigerant and add
an extra cooling load to an air conditioning system maintaining an
internal temperature low enough to condense the refrigerant.
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This invention will now be described, by way of example, with
reference to the accompanying drawings in which:
Figure 1 is a schematic representation of the passive solar panel
of the present invention;
Figure 2 is a partially cutaway view of the exterior of a building
employing the solar panel of the present invention;
~igure 3 is a partially cutaway view of the interior side of an
outside wall of a building employing the solar panel of the present
invention;
; Figure 4 is a sectional view taken along line IV-IV of Figure 3;
and
Figure 5 is a sectional view of a modified solar panel.
Figure 1 illustrates the basic apparatus and operation of the
present invention. A closed loop thermosiphon including a heat
exchanger 20 and a solar receptor or collector 18 located,
respectively, on the interior and e~terior sides of a rigid foam
insulation member 16 is charged with a heat transfer medium such as
refrigerant R-ll. This refrigerant boils at or near room
temperature at atmospheric pressure and at a reasonable pressure
within the temperature range useful for solar heating devices. A
thermosiphon e~is-ts when the solar receptor is receiving a sun
load. In the thermosiphon the liquid level on the boiling side is
generally higher than that on the condensing side because of the
lower mean density of the fluid, but the entire system is at a
substantially constant temperature. The density changes are a
result of the vaporizing and condensing of the fluid. As a result,
liquid refrigerant passing upwardly through the solar receptor 18
is progressively heated until vaporization takes place. The
gaseous refrigerant then passes upwardly and through the insulation
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into the heat exchanger 20. In the heat exchanger, heat is given
off to the room resulting in the condensing of the refrigerant. As
the refrigerant condenses, it becomes more dense and passes
downwardly through the heat exchanger 20 in a counterflow
relationship to the room air. The condensed refrigerant passes
into the refrigerant reservoir ~2 to start the cycle all over.
It is clear that the thermosiphon cycle described will transfer
heat from the solar receptor section of the device to the heat
exchanger located in the interior of the room. In the absence of
solar radiation of sufficient intensity, the solar receptor section
of the device may become colder than the temperature of the
interior of the room. Because the equilibrium level of fluid in
liquid phase is well below the heat e~changer, however, no boiling
can occur, and a reversal of the thermosiphon is impossible. The
cycle, therefor, acts to transfer heat in-~o the room but bars the
flow of heat out of the room.
When the outside air temperature is high, as in sl~nmer weather, it
is not desirable that solar or other heat can be transferred into
the room. Preferably, therefor, the cycle is enabled through a
valve, which may be a solenoid valve, which permits refrigerant
flow when in the heating mode and blocks refrigerant flow in the
off or cooling mode.
In Figures 2-4~ the numeral 10 generally designates the passive
solar panel and construction member of the present invention. With
the exception of the glass and louvered covers 12 and 14,
respectively, the elements of panel 10 are contained, as a unit, in
rigid foam insulation block 16. Preferably, the foam block 16 will
be of sufficient width to span at least two stud widths and so the
resultant space will be boxed in as in the case of a window
opening. As is evident from Fig~re 1, the mose effective p~rt of
the solar receptor 18 is below the liquid level while the heat
exchange takes place above the liquid level. Therefore, for
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economic and/or aesthetic reasons, the double pane glass cover 12
and the louvered cover 14 may be no larger than are necessary an~
the remaining portions of foarn block 16 can be covered by the
respective inside and outside wall coverings. The reservoir 22 is
located on the outside or boiling side so as to provide less
surface for reverse heat leakage.
Foam block 16 may be of any suitable rigid insulating foam such as
polyurethane or cellular polystyrene that will afford the proper
degree of support and insulation capability. Solar receptor 18
which is secured to the foam block ~6 may be of any suitable
material such as blackened copper tubing. Glass cover 12 will
preferably be of double pane construction for better thermal
: insulation between the solar receptor 18 and ambient to thereby
facilitate the heating of refrigerant passing upwardly through the
solar receptor 18. The heat exchanger 20 will preferably be of a
3-row coil construction to reduce the height of the heat exchanger.
The refrigerant will preferably be R-11 and the reservoir 22 will
be only large enough so that the liquid level will remain at a
reasonably constant level even when the refrigerant is being
vaporized in the solar receptor 18. A solenoid valve 24 will
preferably be enabled by the heating thermostat and disabled by the
air conditioning thermostat.
The device of Figures 2-4 meets the objects of the present
invention in that it will perform the required insulating function
while forming part of the interior and exterior wall surfaces and,
in addition, serves a heating function. There are two drawbacks
however in that the solar receptor cannot ef~ectively use the full
height available because of the requirement that the gaseous leg of
the loop contain the heat exchanger and because the heat is being
furnished to the room at a point near the ceiling which is much
higher than is normally desired. These drawbacks are overcome in
the device of Figure 5 in which all structure is numbered 100
higher than corresponding structure in Figures 2 4. Solar receptor
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118 is located between two floors and is of the full height except
for the necessary space for boxing in the opening. The heat
exchanger 120 is located on the floor above the solar receptor 118
a~ a conventional height. The heat exchanger 120 may be either
5 located in a foam insulation block as in the case of the device of
Figures 2-4, or else, the hea~ exchanger 120 can be in the form of
a conventional baseboard heater which extends into the room. The
reservoir 122 is located within the foam 116 to isolate it from
both the room and ambient. The operation of the device would
otherwise be as described above.
