U.S. patent application number 12/666684 was filed with the patent office on 2011-02-24 for roof structure for a solar system.
This patent application is currently assigned to POSNANSKY MARIO. Invention is credited to Mario Posnansky.
Application Number | 20110041428 12/666684 |
Document ID | / |
Family ID | 39166656 |
Filed Date | 2011-02-24 |
United States Patent
Application |
20110041428 |
Kind Code |
A1 |
Posnansky; Mario |
February 24, 2011 |
ROOF STRUCTURE FOR A SOLAR SYSTEM
Abstract
A roof structure (10) for photovoltaic generation of electric
current and/or for heating a flowing medium, in particular an
airflow (14, 20), comprises glass roof panels (24) that are flat,
transparent or equipped at least partially with solar cells (60) of
flat design. Said panels are laid at a spacing (a) from a subroof
(12) with formation of an airtight flat gap (18) that is largely
free of obstructions in the flow direction, and are preferably of
square or rectangular design.
Inventors: |
Posnansky; Mario; (Bern,
CH) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Assignee: |
POSNANSKY MARIO
BERN
CH
|
Family ID: |
39166656 |
Appl. No.: |
12/666684 |
Filed: |
June 25, 2007 |
PCT Filed: |
June 25, 2007 |
PCT NO: |
PCT/CH07/00314 |
371 Date: |
April 17, 2010 |
Current U.S.
Class: |
52/173.3 |
Current CPC
Class: |
F24S 90/10 20180501;
Y02E 10/44 20130101; Y02E 10/47 20130101; F24S 20/67 20180501; H02S
40/44 20141201; F24F 5/0046 20130101; F24S 80/58 20180501; Y02A
30/272 20180101; Y02B 10/10 20130101; Y02E 10/50 20130101; F24S
25/00 20180501; Y02E 10/60 20130101; F24S 2020/17 20180501; Y02B
10/20 20130101; F24S 2020/13 20180501; H02S 20/23 20141201; Y02B
10/70 20130101; E04D 13/17 20130101; H01L 31/048 20130101 |
Class at
Publication: |
52/173.3 |
International
Class: |
E04D 13/18 20060101
E04D013/18 |
Claims
1. A roof structure (10) for photovoltaic generation of electric
current and/or for heating a flowing medium, in particular an
airflow (14, 20), characterized in that glass roof panels (24) that
are transparent or equipped at least partially with solar cells
(60) of flat design and form an airtight flat gap (18) which is
largely free of obstructions in the flow direction (16) are laid
and sealed at a spacing (a) from a subroof (12).
2. The roof structure (10) as claimed in claim 1, characterized in
that the solar cells (60) consist of a photosensitive semiconductor
material that converts photons into electric voltage, in particular
of high purity amorphous silicon.
3. The roof structure (10) as claimed in claim 1, characterized in
that at least a portion of the laid glass roof panels (24) is
constructed as a laminate that comprises a hardened front glass
(70) also having an antireflection layer (72), thereunder a layer
of a plastic embedding compound (74) with the solar cells (60),
accessible uncovered for the sunlight (S.sub.1), and a rear wall
sheet (76) protecting the glass roof panels (24) from below.
4. The roof structure (10) as claimed in claim 1, characterized in
that the glass roof panels (24) are constructed at least partially
as a 35 laminate that comprises a hardened front glass (70), also
with an antireflection layer (72), thereunder a layer of a
transparent plastic embedding compound (74) with the solar cells
(60), and a transparent protective panel or protective sheet (76)
protecting the translucent glass roof panels (24) from below.
5. The roof structure (10) as claimed in claim 1, characterized in
that the glass roof panels (24) are constructed at least partially
as a laminate that comprises a hardened front panel (70), also with
an antireflection layer (72), thereunder thin-layer solar cells
(60), deposited directly onto the glass roof panel (24) with a
chemical or physical deposition method, and a rear wall sheet (76)
protecting the glass roof panels (24) from below, or a
corresponding transparent protective layer or sheet for translucent
glass roof panels (24).
6. The roof structure (10) as claimed in claim 3, characterized in
that the glass roof panels (24) have a grid of flat solar cells
(60) that are arranged abutting or have an all round spacing (b) in
the case of translucent glass roof panels (24), preferably up to
the largest linear dimension of the solar cell.
7. The roof structure (10) as claimed in claim 3, characterized in
that the embedding (74) of the solar cells (60) consists of
plastic, preferably also of transparent ethyl vinyl acetate
(EVA).
8. A solar roof (10) as claimed in claim 1, characterized in that
the flat gap (18) has at least one entrance opening for the cold
airflow (14), at least one exit opening for the warm airflow (20),
and an airtight outer roof edge surround.
9. The roof structure (10) as claimed in claim 1, characterized in
that the spacing (a) between the subroof (12) and the glass roof
panels (24) is in the range of 10-30 mm, preferably approximately
20 mm.
10. The roof structure (10) as claimed in claim 1, characterized in
that the subroof (12) and the glass roof panels (24) run parallel
or, particularly given glass roof panels (24) narrowering in the
flow direction (16) of the air, form a widening flat gap (18) in
this direction.
11. The roof structure (10) as claimed in claim 1, characterized in
that the square or rectangular glass roof panels (24) are laid in
overlapping sealed fashion and preferably with a diagonal
approximately in the flow direction (16) of the air.
12. The roof structure (10) as claimed in claim 1, characterized in
that the glass roof panels (24) are supported in the corner region
or with sealing and collecting tracks (66) running in the flow
direction (16) of the air.
13. The roof structure (10) as claimed in claim 12, characterized
in that the tracks (66) have through openings for the airflow (14,
20) and the electrical cabling, which is preferably of flat
design.
14. The roof structure (10) as claimed in claim 1, characterized in
that the individual glass roof panels (24) are sealed with a frame
(68) and are laid and supported on a plane or in the form of a
shingle roof.
15. The roof structure (10) as claimed in claim 1, characterized in
that the subroof (12) is covered with a black, preferably selective
absorber layer (64) for sunlight (S.sub.2), in particular in the
region of transparent and translucent glass roof panels (24).
16. The roof structure (10) as claimed in claim 1, characterized in
that, in the case of sloping roofs, glass roof panels (24) covered
completely or to a high degree by solar cells (60) are arranged in
the lower region, while glass roof panels (24) with a low degree of
cover or complete transparency are arranged in the upper
region.
17. The roof structure (10) as claimed in claim 1, characterized in
that a pipeline system (30) for transporting the warm airflow (20)
away is connected to the exit openings.
18. The roof structure (10) as claimed in claim 1, characterized in
that a ventilator (28) which is preferably sensor controlled in
accordance with the intensity of the sunlight (S.sub.1, S.sub.2) is
arranged, particularly in the region of the exit openings for the
warm air (20) from the flat gap (18), for the purpose of regulating
and supporting the natural airflow (14, 20).
19. The roof structure (10) as claimed in claim 17, characterized
in that a heat exchanger (40), preferably an air/water one, with a
water circuit (42) is installed next to the exit openings for the
warm air (20).
20. The roof structure (10) as claimed in claim 1, characterized in
that a closed circuit with a ventilator (28) and a heat exchanger
(40) is constructed for the airflow (14, 20) through the flat gap
(18).
Description
[0001] The invention relates to a roof structure for photovoltaic
generation of electric current and/or for heating a flowing medium,
in particular an airflow. The roof structure also serves as a whole
for all the general functions of a roof.
[0002] The use of the daily incident solar radiation of roofs and
facades of inhabited and uninhabited buildings for the purpose of
obtaining energy in the form of electric current and heat has
already acquired great significance.
[0003] Because of the finite nature of fossil energy sources and of
uranium, the exploitation of inexhaustible energy sources such as
those of the sun is of great importance for our future power
supply.
[0004] The reduction of combustion and/or increased use of fossil
energy sources is also necessary on ecological grounds.
[0005] Developments of recent years have shown that solar current
and heat can be obtained on a large scale. Even today the annular
production of solar cells for power generation is over 1400 MW,
corresponding to an area of approximately 14 km.sup.2. The present
annual growth rate is approximately 40%. By 2004 nearly 6 million
m.sup.2 of collector area had been installed on roofs in Germany
alone for the purpose of obtaining heat. This area is to be doubled
by 2012.
[0006] While photovoltaic modules are now being mounted in larger
numbers on roofs, it has become normal to cover roof segments with
thermal collectors by laying water carrying absorbers. However, for
reasons of cost and esthetics the technical development is leading
increasingly to the integration of the solar systems in the roof
skin, facades and skylights and shading devices. In addition, the
photovoltaic modules and thermal collectors are also taking over
the usual function of roofs and facades.
[0007] Increasing use is being made of large area photovoltaic roof
elements as a "solar roof" for the roof structure. The German
company SUNWORLD AG is marketing an appropriate solar roof. It is
necessary to take specific, complicated measures for fastening, but
above all for attaining waterproofness (side and transverse
profiles, rubber seals etc.). Separately therefrom, thermal, mostly
water carrying solar collectors are being installed on or in the
roofs. Also known are so called air correctors that are used as
roof structures chiefly for drying hay with the aid of the warm air
generated. A very esthetic design of overlapping roofing shingles
for photovoltaic current generation is known from U.S. Pat. No.
5,990,414 A.
[0008] The photovoltaic modules or roof elements themselves consist
essentially of thin, fragile silicon solar cells of flat design in
the form of strips or plates. For the purpose of protection against
mechanical and chemical damage, the cells are embedded in an
elastic transparent material, usually EVA (ethyl vinyl acetate)
between the front, transparent front side of hardened glass or
plastic, and a rear sheet or glass. The solar cells are
interconnected electrically such that the module voltage generated
can be tapped via an appliance outlet, mostly arranged at the rear.
A multiplicity of such modules or roof elements are connected in
series and in parallel, in order to obtain the respectively desired
system voltage/DC power. The current is mostly fed into a public
grid via an inverter, or buffered in batteries in the case of small
island systems.
[0009] Thin layers are known that are made from amorphous silicon,
CulS2, or other semiconducting materials or chemical compounds that
are likewise used to construct modules or roof and facade elements.
These layers are applied to glass or transparent plastic, plastic
sheets being used on the front and/or rear for protection against
mechanical or chemical influences.
[0010] Solar systems, in which insulation is used for the purpose
of heating flows of water or air carried in pipeline systems and
current is simultaneously generated by means of photovoltaics are
known, though scarcely used to date. The total cost of such roofs
fitted with solar systems is very high, and casts doubt on an
important advantage of multifunctionality. The functionality and
heat yield are unsatisfactory, just as are the esthetic factors and
suitability for construction of standard roofs. Again, the known
systems are not suitable for the mass production that is required
to lower the costs of power generation. They mostly also have
complicated structures for integration in the roof. The roof
elements that obtain power, which can replace conventional roof
elements (tiles, shingles etc.) would need to be able to be
designed and installed cost effectively. All the factors mentioned
impair the cost effectiveness of obtaining power and heat in
combination.
[0011] The object of the present invention is therefore to provide
a roof structure of the type mentioned at the beginning that
enables decisive cost reductions in conjunction with high
operational reliability, and includes the advantages of
multifunctional power generation without neglecting the esthetic
requirements of the roofs built. Furthermore, it is the object of
the invention also to provide cost effective solutions for the roof
elements that obtain energy.
[0012] The object is achieved in accordance with the invention by
virtue of the fact that glass roof panels that are transparent or
equipped at least partially with solar cells of flat design and
form an airtight flat gap which is largely free of obstructions in
the flow direction laid and sealed at a spacing from a subroof.
Specific and developing embodiments are the subject matter of
dependent patent claims.
[0013] The flat gap preferably has at least one entrance opening
for the cold air, at least one exit opening for the warm air and an
airtight outer roof edge surround or airtight lateral boundaries of
the flat gap.
[0014] Guided through the flat gap is an airflow that is cold when
introduced and heated and outlet again into the atmosphere when
used. In certain instances, it is also possible to install closed
circuits that are operated with air or another gaseous medium.
[0015] The expression, generally used here, "glass roof panels",
fully having the function of roof elements--for example for
substitution of roof tiles, roof shingles etc.--also covers panels
made from all other suitable transparent materials.
[0016] The spacing between the subroof of flat design (without the
usual roof ribs) and the glass roof panels is preferably in the
range of 15-30 mm. The spacing is determined on the basis of design
parameters such as, for example, the desired temperature rise,
height of the roof, expected thermal efficiency and the air speed
determined.
[0017] According to one variant, the flat gap can widen upward.
This is the case, in particular, when the glass roof panels, and
thus the roof or the roof part itself narrow upward (pitched
roof).
[0018] The glass roof panels of rectangular or square design
fulfill the function of roofing materials, in particular of
tiles.
[0019] In the case of glass roof panels of rectangular design,
these are laid in an overlapping fashion and sealed with known
means such that an airtight flat gap is ensured. Longitudinal
profiles are constructed at the side and ensure tightness,
maintenance of the spacing, and fastening. In the case of
rectangular, nonoverlapping glass roof panels that abut one
another, the sealing is with rubber profiles and longitudinal
profiles that prescribe the abovementioned spacing of 15-30 mm and
enable the panels to be fastened.
[0020] A particular refinement of the inventive roof structure
comprises specially designed square glass roof panels that are laid
with their diagonals in a vertical direction and in a fashion
overlapping on both sides. Cost savings result, in particular, from
the fact that rain water is certain to flow off without further
measures, that is to say profiles and the like for the lateral
sealing of the panels can be eliminated. This design is
particularly suitable for mass production and is exceptionally cost
effective to lay.
[0021] The square glass roof panels are esthetically attractive as
roof elements and are used for covering the entire roof including
possible adjacent roofs (also without power being obtained). In
addition to functions that obtain current and heat, they are also
configured according to the invention for the incidence of light
(skylight function), including in combination with the power
generation as translucent roof elements.
[0022] According to a further laying variant, the glass roof panels
can, however, always be sealed, laid and supported on a plane or in
the form of a shingle roof while being held with a frame. For its
part, the frame comprises fastening feet that are not allowed to
impede the throughflow of air.
[0023] Since the glass roof panels laid in accordance with the
invention replace a conventional roof, these are always watertight
in the case of storm gusts and fulfill the snow load regulations.
It is also possible to walk on the glass roof panels.
[0024] According to the invention, these glass roof panels can be
used as follows for the roof structure: [0025] as conventional
glass roof panels--transparent or opaque--for covering roof parts
without use for power. This holds, in particular, for the square
roof panels that are esthetic and easy to install. The preferably
doubly overlapping glass roof panels are fastened at the four
corners on the subroof and simultaneously pressed onto one another
in order to attain tightness. [0026] As thermal glass roof panels
for thermal use by heating the airflow in the air gap thereunder.
In this case, the glass roof panels are transparent for full solar
radiation. The radiation is absorbed by a selectively coated
absorber that serves for directly efficient heating of the air to
high useful temperatures (up to 100.degree. C.) [0027] As
photovoltaic glass roof panels with and without simultaneous
thermal use. If no heat is obtained with the aid of the airflow in
the gap therebehind, this is suitable for performance enhancing
cooling of the cells. The air is heated at the rear side of the
glass roof panels, useful temperatures of up to approximately
55.degree. C. being attainable. [0028] As transparent glass roof
panels with a skylight function. [0029] As partially transparent
glass roof panels for photovoltaic power generation (skylight
shaded by the cells), subroof transparent, or only with the roof
girders. [0030] As partially transparent glass roof panels for
photovoltaic and thermal power use.
[0031] The roof structure can be installed in the form of roof
sections with only a thermal function, only an electrical function,
only a skylight function with an electrothermal function (air
temperatures of up to 55.degree. C.), and in the form of
downstream, purely thermal glass roof panels for obtaining high
temperatures at the output. The thermal roof panels therefore act
as a "booster". Further combinations for the use of the glass roof
panels are likewise possible in conjunction with the transparent or
partially transparent properties.
[0032] Particularly with the preferred roof structure consisting of
the square, esthetic glass roof panels, there is the possibility of
building ultramodern multifunctional roofs in the case of which
power is produced simultaneously and fossil fuels are replaced for
obtaining heat. Given the installation of dozens of square
kilometers, interesting prerequisites for large scale economic use
of solar energy can be attained worldwide by the mass production of
these roof elements in combination with thermal use. In Switzerland
alone it is possible to switch fully to inexhaustible
environmentally friendly energy sources if as little as 10% of the
areas of roofs and facades of the presently existing total area of
700 km.sup.2 is used. Currently, 12 km.sup.2 of roofs are built or
renovated annually in Switzerland. In Germany the abovementioned
numbers are tenfold.
[0033] The embodiments of the various glass roof panels are
described below with reference to the example of the square doubly
overlapping glass roof panels.
[0034] Glass roof panel with simple roof function. This consists of
a front hardened glass roof panel with a sheet, laminated on the
rear, for coloring, as well as the fastening elements and pressure
elements at the four corners. However, other materials can also be
used for this function with the same geometric structure and
fastening technique. [0035] If the glass remains transparent, the
glass roof panel can be used with skylight function. [0036] Glass
roof panel with purely thermal function. This consists of hardened
glass with the same geometric structure and fastening technique.
[0037] Glass roof panel with photovoltaic function. This consists
of a photovoltaic cell laminate in accordance with the layer
assembly (silicon cells or thin-layer cells) described at the
beginning. [0038] Glass roof panel with photovoltaic function and
passage of light, as well as the same geometric structure and
fastening technique. These consist of a photovoltaic laminate in
accordance with the layer assembly described at the beginning, the
solar cells being interconnected electrically with the maintenance
of a spacing between the cells for the purpose of transmitting
light. The geometric structure and fastening technique once again
remain the same.
[0039] Conventional thermal collectors for producing hot water and
for assisting heating with necessary installation of metallic
absorbers with the associated water carrying tubes, or even vacuum
collectors for "gathering in" sunbeams over an entire area are more
expensive by a multiple than the inventive absorbers of solar
radiation over the same area with an airflow and downstream heat
exchanger for transferring the heat to the fluid medium. In the
case of the photovoltaic roof panels, the investments for the
simultaneous heating of the airflow have, in addition, already been
made, the costs for a conventional roof element having been
deducted.
[0040] However, good heat transmission is a prerequisite for an
effective transfer of heat from the photovoltaic roof panels to the
air circulating therebehind. For the inventive roof structure, the
gap width between panel and subroof is preferably, as mentioned,
15-30 mm, depending on the definition of the decisive design
parameters.
[0041] In order to maintain the air temperature at the exit, the
air speed or flow rate is preferably regulated with the aid of a
ventilator that is controlled by a solar sensor or driven with
solar cells.
[0042] According to one variant, for the purpose of further
temperature increase, for example above the photovoltaic roof
panels, it is expedient to dispense with the installation of solar
cells and to arrange the transparent thermal glass roof panels. In
this case, the radiation passes through the glass roof panel
directly onto a selective absorber sheet thereunder past which the
air flows and is heated. A selective absorber has the property that
the solar radiation (shortwave) is virtually completely absorbed
(black body), while the thermal emission of the hot absorber is
avoided as far as possible. This is achieved by virtue of the fact
that the absorber sheet has a low emission factor for the emission
at longer wavelengths.
[0043] The selective sheet is, for example, a solid sheet of
ceramic and metal termed CERMET. The coated absorber sheet is long
lived and heat resistant. It can be touched, cleaned, shaped,
welded and riveted. The absorption factor is 95%, the emission
factor only 5%. These requirements are fulfilled, for example, by
the product Sunselect from Interpane Solar GmbH & Co. in
Germany.
[0044] If the selective absorber sheet is fastened on the subroof,
the air flows between it and the transparent glass roof panel. The
thermal efficiency, and thus the attainable air temperature are
less than when the air flows through behind the selective absorber
sheet. The absorber sheet is preferably fitted at a spacing of
approximately 10 mm below the transparent glass roof panel.
[0045] In a preferred variant, the heated air flows in the gable
region directly through an elongated air/water heat exchanger
running along the gable. Air, for the most part cooled, is caught
by collecting channels downstream of the exchanger and, for
example, guided by means of a ventilator operated by solar cells
directly into the ambient air or--if still being used for heating
purposes--into the interiors. In certain applications, an airflow
supported and regulated by a ventilator is not required, since the
uplift resulting from the heating of the air is sufficient to guide
the hot air through the heat exchanger arranged along the
gable.
[0046] According to a further variant, the exiting hot air is
guided via a pipeline system to an air manifold heat exchanger
outside the roof region, where a water circuit is expediently
heated, in turn. The residual heat can be used for further useful
purposes before it is outlet into the atmosphere as expulsion
air.
[0047] The advantages of the inventive roof structure are evident,
reference has already been made above to the applications for using
the heat and to the cost advantages, in particular there is no need
for expensive pipeline systems to be laid in the entire roof
region, and the continuously open flat gap requires far lower
investment costs and makes no demand on maintenance.
[0048] The invention is explained in more detail with the aid of
exemplary embodiments that are illustrated in the drawing and are
also the subject matter of dependent patent claims. In the
drawing,
[0049] FIG. 1 shows a vertical section through half a solar roof
with overlapping glass roof panels,
[0050] FIG. 2 shows a variant in accordance with FIG. 1, with glass
roof panels laid in a flat fashion and a ventilator,
[0051] FIG. 3 shows a detail III of FIG. 2 with a standard type
support,
[0052] FIG. 4 shows a roof gable with a heat exchanger,
[0053] FIG. 5 shows a variant in accordance with FIG. 4 with an air
manifold heat exchanger,
[0054] FIG. 6 shows a view of a specimen roof with five laying
variants R-V,
[0055] FIG. 7 shows a partial vertical section through the laying
variant S,
[0056] FIG. 8 shows a partial vertical section through the laying
variant V,
[0057] FIG. 9 shows a laying variant with square glass roof panels
set on end,
[0058] FIG. 10 shows a laying variant of the glass roof panels in
the form of a shingle roof,
[0059] FIG. 11 shows a flat laying of the glass roof panels in
accordance with FIG. 2,
[0060] FIG. 12 shows a laying variant of tapering glass roof panels
for a pitched roof,
[0061] FIG. 13 shows a partial section through a glass roof
panel,
[0062] FIG. 14 shows a variant in accordance with FIG. 13,
[0063] FIG. 15 shows a further variant of a glass roof panel,
[0064] FIG. 16 shows a plan view of a roof glass panel with tightly
arranged solar cells,
[0065] FIG. 17 shows a plan view of a translucent glass roof panel,
and
[0066] FIG. 18 shows a view of a solar roof with glass roof panels
set on end.
[0067] FIG. 1 shows a roof structure 10 for a solar system for the
photovoltaic production of electric current and/or for heating a
cold airflow 14. The roof structure 10 is arranged removed in a
parallel fashion by a spacing a from a subroof 14. The spacing a is
approximately 20 mm here.
[0068] The subroof 12 and the roof structure 10 form a flat gap 18
that is virtually free from obstructions in the flow direction 16
and in which the cold air 14 is continuously heated, exits as a hot
airflow 20 into a gable space 22 and is fed from there directly to
a further use.
[0069] It is of substantial importance that the flat gap 18 extends
over the entire roof structure (saving of roof ribs), and that
there are no substantial obstructions in the flow direction 16. The
flat gap 18 is sealed in the outermost region of the roof structure
with the entire circumference or a part thereof. It is thus
possible for a natural flow to build up in the direction 16 and
heat the cold air 14, which expands and rises in the flow direction
16 because of the lower density.
[0070] A filter 15 is also expediently arranged at the entrance
opening for the cold air 14. The hot airflow 20 exiting in the
gable space 22 can be used directly for drying.
[0071] FIG. 2 differs from FIG. 1 particularly in that the glass
roof panels 24 are not arranged in an overlapping fashion, but on a
plane, again at the spacing a from the subroof 12. The glass roof
panels 24 are held by standard-type supports 26 of small flow cross
section at the spacing a. The airflow in the direction 16 is
assisted by at least one ventilator 28 in the gable space 22. This
ventilator 28 is connected to at least one exit opening of the hot
airflow 20 via a suction tube 30. A variant that is not illustrated
serves for regulating the ventilator performance. The ventilator
can also be driven directly by solar cells, as a result of which a
sensor is eliminated. Both variants serve to maintain the
temperature level under varying radiation conditions.
[0072] FIG. 3 illustrates in detail a standard-type support
anchored in the subroof 12. A screw 36 with a peripheral bearing
flange 32 and a guide arbor 34 ensures the setting of a flat gap 18
in the abovementioned region of, expediently, approximately 15 mm.
The mounted glass panels 24 are secured with a head screw. The
laminate structure of the glass roof panels 24 is shown in FIGS. 13
to 15.
[0073] The gable space 22 illustrated in FIG. 4 and that can also
be configured as a manifold, includes a heat exchanger 40 that is
connected upstream of the ventilator 28 (FIG. 2), in the hot
airflow 20. The heat exchanger absorbs a substantial fraction of
the heat content of the air and feeds the latter to a water circuit
42 in a way known per se. Said circuit comprises a supply lead 44
and a down lead 46, for example in a hot water or heating circuit.
Opening into the gable space 22, which is sealed in an airtight
fashion, is an exhaust-air line 50 through which the still hot air
can be fed to a further use. According to one variant, the still
hot air exits as expulsion air into the external atmosphere via an
exit opening indicated by an arrow 52. The airflow can be deflected
or split up with a baffle 54.
[0074] FIG. 5 shows the further course of the exhaust-air line 50.
After the baffle 54 is opened, the entire hot airflow 20 flows to
an air manifold heat exchanger 56 where the heat content of the air
is, once again, absorbed for the most part by a water circuit 42.
The hot airflow 20 exiting from the air manifold heat exchanger 56,
which has been cooled but is still hot, passes into the atmosphere
as expulsion air 58, or is fed to a further use 60.
[0075] FIG. 6 shows a view of a virtual roof structure 10. In other
words, FIG. 6 corresponds not to a roof that is customary in
practice, but to a specimen roof with as many variants as possible.
Each of the variants R, S, T, U and V would correspond in practice
to a roof or a roof segment. [0076] Variant R. Here, the glass roof
panels 24 are arranged with a photovoltaic function over the entire
roof height. The heating of the air in the rear gap is performed by
the heat transfer of the glass roof panels 24, which have a
temperature of up to 70.degree. C. when the sun is shining. The
useful heat thereby obtained comes in at a temperature level of
45-60.degree. C. [0077] Variant S. Here, the roof consists in the
lower part of glass roof panels 24 with a photovoltaic function. In
the upper part, the air flows under glass roof panels 24 with a
purely thermal function. The solar radiation strikes selective
absorber sheets such that the airflow is further heated depending
on whether it is guided past the front or rear side of the
selective sheet up to a temperature of 60-80.degree. C. [0078]
Variant T. In the case of this roof structure, glass roof panels 24
with a purely thermal function are used over the entire roof height
such that high temperatures of up to 100.degree. C. are attained.
[0079] Variant U. Here, use is made of glass roof panels 24 with a
photovoltaic function and translucent properties. Sunlight enters
between the solar cells 60, which are electrically connected at a
certain spacing. In this roof area, electric current is generated
and the translucent glass roof panels 24 also take over the
function of shaded sky lights. If the selective sheet is used in
the air gap, the skylight function is dropped in favor of the
generation of heat. The temperature level attained in this case for
the useful heat is somewhat higher, owing to the additional
incidence of light, than for the glass roof panels 24 with only
power generation.
[0080] Variant V. Here, glass roof panels 24 with a purely thermal
function are used in the upper roof region for the production of
heat.
[0081] Of course, yet further variants are possible, and individual
variants can be combined with one another.
[0082] In particular, glass roof panels 24 with a skylight function
(roof window) can be installed, or the glass roof panels 24 can be
coated black without solar cells being installed.
[0083] FIG. 7 shows a partial longitudinal section through variant
S in accordance with FIG. 6. Glass roof panels 24 in the lower
region contain solar cells 60 that abut one another on all sides,
and the sunlight S.sub.1 is completely absorbed thereby. The
uppermost two glass roof panels 24 contain no solar cells 60, and
the sunlight S.sub.2 can pass through completely and is completely
absorbed by a black absorber layer 64 applied to the subroof 12,
and this leads to intense heating of the air 20 flowing through.
The absorber layer 64 is applied only in the region of the
completely transparent glass roof panels 24.
[0084] In the embodiment in accordance with FIG. 8, the solar cells
60 are applied with an all-round spacing b corresponding to the
variant V of FIG. 7. Respectively approximately half the sunlight
strikes the solar cells (S.sub.1), or the other half of the
sunlight passes through the glass roof panels 24 and strikes the
selective absorber layer 64 (S.sub.2), which covers the entire
subroof 12. By comparison with FIG. 7, the photovoltaic generation
of electric current is reduced while the heating of the airflow 20
is increased, by contrast.
[0085] Evidently, in accordance with FIG. 8, and to a lesser extent
in accordance with FIG. 7, the flat gap 18 is increased in the flow
direction 16, and this even further improves the effect of the two
completely transparent glass roof panels 24.
[0086] FIG. 9 indicates the preferred laying variant of square
glass roof panels 24. The glass roof panels 24 are set on end, the
diagonals running in the fall line of the roof. The glass roof
panels 24 are arranged in a fashion doubly overlapping downward,
and they are held by standard-type supports 26.
[0087] According to FIG. 10, the glass roof panels 24 are laid
conventionally, that is to say in the form of a shingle roof
overlapping downward on one side. Sealing and collecting channels
66 are laid on both sides and run in a vertical direction, that is
to say in the flow direction 16 of the air guided through. Below
the glass roof panels 24, the sealing and collecting tracks 66 both
provide support and keep the spacing, and have longitudinal
openings (not depicted) for the passage of the air and the cabling.
However, it is not these openings that are important, but the fact
that the tracks 66 run in the direction of the airflow 16 and are
therefore virtually no obstruction.
[0088] In accordance with FIG. 11, square or rectangular glass roof
panels 24 are held like a window in frames 68 which both provide a
seal and support at a spacing a (FIG. 1).
[0089] A variant in accordance with FIG. 10 is illustrated in FIG.
12. The glass roof panels 24 taper rearward, and this is required
in particular for a pitched roof.
[0090] Embodiments in accordance with FIGS. 13 to 15 show a
laminate structure of the glass roof panels 24. Common to all the
embodiments is a panel 70 made from hardened glass. It is generally
possible to walk on this. An antireflection layer 72 that prevents
undesired mirror effects is optional. Visible on the other side of
the plate 70 made from hardened glass is a cell embedding made from
ethyl vinyl acetate EVA for the solar cells 60 of flat design. As
in FIG. 13, these solar cells 60 are arranged in an abutting
fashion, and they pass no sunlight. The EVA layer 74 is protected
by a rear wall sheet 76, for example made from a Tedlar sheet or an
aluminum sheet.
[0091] Arranged on the rear wall sheet 76 is a flat box 78 for
cable outlets and a bridging diode 60. The current conduction takes
place in a way known per se, although it is ensured that the cable
82 is flat and therefore poses little obstruction to the
airflow.
[0092] The laminate structure of the glass roof panel 24 in
accordance with FIG. 14 corresponds substantially to that of FIG.
13. The flat solar cells 60 are, however, embedded in a transparent
EVA layer 74 at a spacing b from one another, the width b of the
transparent strips 90 being greater than the corresponding linear
dimension of the solar cells 60. The rear sheet or panel 76 must
likewise be of transparent design. A translucent glass roof panel
24 in accordance with FIG. 14 has transparent and opaque regions by
definition.
[0093] FIG. 15 shows a further variant of a laminar glass roof
panel 24 in accordance with which the solar cells are deposited
directly onto the underside of the panel 70 made from hardened
glass at a spacing b from one another (thin-layer cell technology).
Also in accordance with FIG. 15, what is involved is a translucent
glass roof panel 24, but with a smaller area fraction of the
transparent strips 90 than in FIG. 14. Depending on the process,
the thin layer that is applied to glass or transparent plastics
lies between two glass or plastic panels.
[0094] FIG. 16 shows in plan view a glass roof panel 24
corresponding to FIG. 13. Solar cells 60, which are of
substantially square design, are laid in a fashion abutting one
another and leave no gap open for the sunlight S.sub.2 to slip
through (FIG. 8). The edge zones 84 serve for the formation of
overlaps. The laid glass roof panels 24 form a roof structure 10
that is opaque to the sun's rays raised (FIG. 6, variant R).
[0095] FIG. 17 shows a translucent glass roof panel 24 with solar
cells 60 arranged at a spacing b in accordance with FIG. 15. The
laid glass roof panels 24 also have substantial transparent strips
90.
[0096] FIG. 18 shows a roof structure 10 for a solar system for the
photovoltaic generation of electric current and for strong heating
of air in the flow direction 16. Use is made in principle of the
laying pattern S of FIG. 6, but with glass roof panels 24, standing
on end, of square shape with diagonals in the direction of fall. In
the lower region, glass roof panels 24 are arranged with square
solar cells 60, in an abutting arrangement, in an overlapping
fashion on two sides and sealed. Also inserted in this region is a
transparent or (not illustrated) translucent glass roof panel 24
that takes over the function of a roof window 88, and this is
sensible chiefly when the roof consists only of opaque glass roof
panels 24.
[0097] Purely thermal glass roof panels 24 without solar cells are
arranged in the uppermost, so called "booster region". Here, the
already preheated air is heated to a temperature of about
100.degree. C. The air passes directly into a heat exchanger 40
with a water circuit 42 for the production of hot water. As already
indicated in FIG. 4, this heat exchanger 40 is arranged in the
gable region.
[0098] Arranged in the lowermost roof region are so called
"dummies" 90, black coated glass roof panels 24 without a
photovoltaic effect, in the case of which "solar cells" are printed
on by screen printing.
TABLE-US-00001 List of reference numerals Case: FID-A6/01-CH No.
Designation 10 Roof structure 12 Subroof 14 Cold airflow 15 Filter
16 Flow direction 18 Flat gap 20 Warm airflow 22 Gable space 24
Glass roof panels 26 Standard-type supports 28 Ventilator 30
Suction tube 32 Bearing flange 34 Guide arbor 36 Screw 38 Head
screw 40 Heat exchanger 42 Water circuit 44 Supply lead 46 Down
lead 48 Baffle 50 Exhaust-air line 52 Arrow 54 Baffle 56 Air
manifold heat exchanger 58 Expulsion air 60 Solar cells 62
Transparent strips 64 Absorber layer 66 Sealing and collecting
channel 68 Frame 70 Hardened front glass 72 Antireflection layer 74
EVA embedding 76 Rear wall sheet 78 Flat box 80 Bridging diode 82
Flat cables 84 Edge zones 86 Roof window 88 Dummies 90 Transparent
strips 92 94 96 98 100 102 104 106 108 110 112 114 116 118 120 122
124 126 128 130 132 134 136 Special numerals a Wide flat gap 18
S.sub.1 Sunlight on 60 S.sub.2 Sunlight on 64 b Spacing between 60,
wider 90
* * * * *