EP3137820A1 - Glazed solar collectors - Google Patents
Glazed solar collectorsInfo
- Publication number
- EP3137820A1 EP3137820A1 EP15722747.1A EP15722747A EP3137820A1 EP 3137820 A1 EP3137820 A1 EP 3137820A1 EP 15722747 A EP15722747 A EP 15722747A EP 3137820 A1 EP3137820 A1 EP 3137820A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- coating
- glass
- cavity
- glazing
- igu
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 230000005855 radiation Effects 0.000 claims abstract description 34
- 238000000576 coating method Methods 0.000 claims description 109
- 239000011248 coating agent Substances 0.000 claims description 101
- 239000011521 glass Substances 0.000 claims description 59
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 43
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 42
- 229910052742 iron Inorganic materials 0.000 claims description 22
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 claims description 8
- 239000011737 fluorine Substances 0.000 claims description 8
- 229910052731 fluorine Inorganic materials 0.000 claims description 8
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 claims description 8
- 229910001887 tin oxide Inorganic materials 0.000 claims description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 7
- 239000004332 silver Substances 0.000 claims description 5
- 229910052709 silver Inorganic materials 0.000 claims description 5
- 238000000034 method Methods 0.000 claims description 4
- 239000000463 material Substances 0.000 claims description 3
- 239000000203 mixture Substances 0.000 claims description 3
- 238000004891 communication Methods 0.000 claims description 2
- 150000001875 compounds Chemical class 0.000 claims description 2
- 230000008569 process Effects 0.000 claims description 2
- 238000004544 sputter deposition Methods 0.000 claims description 2
- 230000001419 dependent effect Effects 0.000 claims 1
- 238000010438 heat treatment Methods 0.000 abstract description 16
- 230000000694 effects Effects 0.000 abstract description 7
- 238000005338 heat storage Methods 0.000 abstract description 5
- 238000004140 cleaning Methods 0.000 description 6
- 230000005540 biological transmission Effects 0.000 description 5
- 238000010792 warming Methods 0.000 description 5
- 230000008901 benefit Effects 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 3
- 239000006117 anti-reflective coating Substances 0.000 description 2
- 239000000356 contaminant Substances 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 230000002829 reductive effect Effects 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 238000004887 air purification Methods 0.000 description 1
- 230000000845 anti-microbial effect Effects 0.000 description 1
- 230000003667 anti-reflective effect Effects 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 238000000429 assembly Methods 0.000 description 1
- 230000000712 assembly Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 239000005329 float glass Substances 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000005816 glass manufacturing process Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000003973 irrigation Methods 0.000 description 1
- 230000002262 irrigation Effects 0.000 description 1
- 230000002147 killing effect Effects 0.000 description 1
- 230000000670 limiting effect Effects 0.000 description 1
- 244000005700 microbiome Species 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 230000001699 photocatalysis Effects 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000005361 soda-lime glass Substances 0.000 description 1
- 125000006850 spacer group Chemical group 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 239000004408 titanium dioxide Substances 0.000 description 1
- 238000009423 ventilation Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
- F24S70/00—Details of absorbing elements
- F24S70/30—Auxiliary coatings, e.g. anti-reflective coatings
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
- C03C17/34—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions
- C03C17/36—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal
- C03C17/3602—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal the metal being present as a layer
- C03C17/3657—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal the metal being present as a layer the multilayer coating having optical properties
- C03C17/366—Low-emissivity or solar control coatings
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
- F24S70/00—Details of absorbing elements
- F24S70/10—Details of absorbing elements characterised by the absorbing material
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
- F24S80/00—Details, accessories or component parts of solar heat collectors not provided for in groups F24S10/00-F24S70/00
- F24S80/50—Elements for transmitting incoming solar rays and preventing outgoing heat radiation; Transparent coverings
- F24S80/52—Elements for transmitting incoming solar rays and preventing outgoing heat radiation; Transparent coverings characterised by the material
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C03C2218/00—Methods for coating glass
- C03C2218/30—Aspects of methods for coating glass not covered above
- C03C2218/365—Coating different sides of a glass substrate
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/20—Filters
- G02B5/208—Filters for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B10/00—Integration of renewable energy sources in buildings
- Y02B10/20—Solar thermal
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/40—Solar thermal energy, e.g. solar towers
Definitions
- the invention concerns apparatus and method for collecting solar radiation and converting same to a form of energy suitable for space heating in buildings.
- the solar collector comprises a collector panel which defines an at least partially enclosed space.
- the collector panel known as a transpired solar collector, comprises energy absorbing sides, air-inlet openings connecting the outside environment with the at least partly enclosed space and an air-outlet duct connected to the at least partly enclosed space. Solar energy is absorbed by the energy absorbing sides and this causes heating of air in the outside environment, in the immediate vicinity of the panel.
- WO 2010/086126 also describes systems for storing and managing the heat derived from the panels. The effectiveness of the apparatus described in WO 2010/086126 is affected by wind which disturbs the warmed air in the vicinity of the panel, before it passes through the inlet openings.
- Chinese Utility Model No. eN 201517854 U describes another system in which air, warmed by solar radiation, is used for space heating. Again, a panel is disclosed, with holes through which warmed air passes and is recovered for building heating.
- the apparatus also includes a glazing, arranged in parallel spaced relationship with the panel so that air between the glazing and the panel is warmed by solar radiation before being passing through the holes.
- a glazing comprising glass having a high iron content is recommended because such glass absorbs solar radiation more effectively, better to heat the air between the glazing and the panel.
- the present invention provides such means, whereby solar energy is collected with a high degree of efficiency and made available for uses such as internal space heating in buildings or heat storage and management e.g., according to the methods described in WO 2010/086126.
- apparatus for collecting solar energy comprises: a cavity, a glazing, arranged to allow solar radiation to pass therethrough and enter the cavity, an inlet aperture, arranged to allow air to enter the cavity from an external environment and an outlet aperture, arranged to allow air warmed by the solar radiation, to exit the cavity; characterised in that the glazing comprises a coated glass.
- the coating may comprises a low emissivity coating, a pyrolytically deposited fluorine doped tin oxide a titania coating or an antireflection coating.
- the coating is located on either the internal surface, or the external surface of the glass, relative to the cavity.
- the glazing comprises a major sheet and has integral glass sidewalls.
- Two glazings may be employed, each glazing comprising a major sheet and two integral glass sidewalls, and the glazings being arranged to define the cavity therebetween.
- the apparatus may include an Insulated Glazing Unit (IGU), said IGU comprising at least two glass sheets.
- the IGU may comprise two glass sheets wherein the coating is located on surface #4 of the IGU.
- the coating on surface #4 of the IGU may comprise titania or pyrolytically deposited fluorine doped tin oxide.
- the IGU may comprise two glass sheets wherein the coating is a low E coating located on surface #3 of the IGU.
- This coating may be the product of a sputter deposition process and may comprise silver or a compound of silver.
- the coating may be located on surface #1 of the IGU and may comprise an antireflection coating, a titania coating or a pyrolytically deposited fluorine doped tin oxide.
- the IGU may include a glass sheet comprising a tinted glass.
- the tinted glass would have a composition comprising at least 0.15wt% iron.
- the apparatus may include at least one sheet of glass comprises a low iron content glass, having an iron content of less than 0.02wt%, preferably less than 0.015wt% most preferably less than 0.01wt%.
- the apparatus may include a transpired solar collector arranged to divide the cavity into first and second regions, the first region being bounded by the glazing wherein the collector comprises a sheet of material having a plurality of holes, the holes providing communication between the two regions, and wherein the inlet aperture is arranged to allow air to enter the first region and the outlet aperture is arranged to allow air to leave the second region.
- means may be included for directing a flow of water on to said surface.
- apparatus for collecting solar energy comprises: a cavity, a glazing, arranged to allow solar radiation to pass therethrough and enter the cavity, an inlet aperture, arranged to allow air to enter the cavity from an external environment and an outlet aperture, arranged to allow air warmed by the solar radiation, to exit the cavity; characterised in that the glazing comprises a low iron glass.
- the glass comprises less than 0.02wt% iron, more preferably less than 0.015wt% iron and even more preferably, less than 0.01wt% iron.
- Figures 1 - 3 illustrate various embodiments of the invention employing a single glazing on a simple undivided cavity
- Figures 4 - 8 illustrate various embodiments of the invention employing a multiple glazing on a simple undivided cavity
- FIGS. 9 - 14 illustrate various embodiments of the invention in which the cavity is divided by a transpired solar collector
- Figure 15 illustrates apparatus according to the invention in which a glazing having a 'U' shaped cross-sectional profile is employed;
- Figure 16 illustrates apparatus employing a glazing having a 'U' shaped cross-sectional profile wherein the cavity is divided by a transpired solar collector and
- Figures 17a and 17b illustrate embodiments wherein two glazings having a 'U shaped cross-sectional profile are used to define the cavity.
- Figures 18 and 19 illustrate a test apparatus used to evaluate the performance of glazed solar collectors according to the invention both with and without a Transpired Solar Collector sheet;
- Figure 20 shows the performance of various embodiments of the invention in terms of rise in air temperature achieved for a given solar radiation and
- Figure 21 shows the improvement in performance over a simple uncoated glazed cavity that may be achieved by various embodiments of the invention.
- a first embodiment of the invention includes a cavity 1 which is partly defined by a glazing 2.
- the cavity further comprises side walls (not shown) parallel to the plane of the page and may be arranged against the wall of a building which serves as another wall of the cavity.
- an insulated panel 3 which may be fixed to the exterior of a building, may serve as the back wall of the cavity. Examples of insulated panels which might serve this purpose include Trisomet® 333 manufactured by Tata Steel.
- cold air enters the cavity via a lower aperture 4, is warmed by solar radiation passing through the glazing and then exits cavity via an upper aperture 5. After exiting the cavity, the warmed air may be directed to the interior of a building to provide space heating or the heat may be extracted for storage or other use by means well known to persons skilled in the art.
- the low iron glass such as Pilkington OptiwhiteTM may be used for the glazing as this further reduces the amount of solar energy absorbed by the glass and facilitates transmission of energy to the cavity.
- the low iron glass comprises ⁇ 0.02wt% iron, more preferably ⁇ 0.015wt% and most preferably ⁇ 0.010wt%.
- a coating 6 is applied to the inner surface of the glazing.
- the coating 6 comprises a low emissivity (low E) coating (designated 6a in subsequent drawings) which reduces the transmission of infrared radiation. Thus loss of heat through the glazing, from within the cavity, is reduced.
- low E low emissivity
- the low E coating is preferably chosen to optimise the trade-off between solar gain and heat trapping by balancing transmission of solar radiation into the cavity against heat loss by infrared radiation from the cavity.
- an optimum sheet resistance of between 15 and 30 ohm per square has been established.
- Pilkington K GlassTM is a low E glazing material suitable for use in this embodiment of the invention.
- K GlassTM comprises a fluorine doped tin oxide coating on a colour suppressing silicon oxy carbide coating.
- the coating 6 may comprise a functional coating (designated 6b in subsequent drawings) such as titanium dioxide (titania). Titania coatings are known to offer an antimicrobial effect via a photocatalytic effect, whereby highly reactive free radicals are generated from oxygen and moisture under the influence of ultraviolet radiation in (for example) sunlight. Inclusion of such a coating on the inner surface of the glazing causes decomposition of organic contaminants and killing of microorganisms to provide a purified air supply for the building.
- a functional coating such as titanium dioxide (titania).
- Such irrigation means typically comprises a water outlet such as a nozzle, array of nozzles or a pipe with one or more holes, connected to a water supply and arranged to direct a flow of water on to the coated surface.
- the self-cleaning action is enhanced where a hydrophilic coating is used which causes water droplets to spread on the surface and run off easily.
- Pilkington ActivTM is a titania-based self-cleaning glazing which serves in this embodiment.
- such embodiments may optionally include means for irrigating said inner surface.
- a functional coating 6b is applied to the external surface of the glazing.
- an antireflective coating increases the effectiveness of the device by increasing the amount of solar radiation which is transmitted through the glazing 2 to provide heading of air in the cavity 1.
- Pilkington OptiviewTM serves as a suitable glazing product in this embodiment.
- the functional coating 6b could comprise a self-cleaning coating such as found on Pilkington ActivTM so that the exterior glass surface remains relatively free from contaminants that would otherwise inhibit transmission of solar radiation and adversely affect the visible appearance of the installation.
- Pilkington ActivTM also offers anticondensation properties in this orientation as its hydrophilic properties cause water droplets which gather on the outer surface to spread and readily run off.
- Anticondensation properties are also achieved using pyrolytically deposited fluorine doped tin oxide based coatings such as found in Pilkington K GlassTM or Energy
- the glazing could include coatings on both sides.
- the inner surface coating 6 could, for example be a low E coating or a titania coating.
- the coating 6b on the external surface could be a functional coating such as anticondensation, antireflective or self-cleaning.
- the emissivity of the inner coating 6 is less than that of the outer coating 6b.
- the invention may include an insulated glazed unit (IGU) 7 of the type well known in the art and comprising two or more glazings 2, 8 held apart by spacers 9 to define a low thermal conductivity gap 10, typically containing air or another gas.
- IGU insulated glazed unit
- a coating 6 is shown on the innermost glass surface which, as in the previous embodiment (figure 1) might be a low E coating or a titania coating.
- the glass surfaces are numbered from #1 to #4, number 1 being the outermost (i.e. furthest from the building, contacting the external environment) so in figure 3, the coating 6 is shown on surface #4.
- conventional numbers referring to the various glass surfaces are underlined in order to distinguish them from numerals used to identify features in the drawings.
- a low E coating 6a may be located on an internal glass surface with the IGU.
- the low E coating 6a is shown on surface 3. Since this surface is protected from the elements due to its location within the IGU, a so called 'soft coating' may be used such as a silver-based sputtered coating of the type known in the art. Pilkington OptithermTM is an example of a product having such a coating.
- FIG. 6 use of a multi-glazed IGU offers a number of options for the application of various coatings to the various surfaces.
- a functional titania coating 6b is shown on surface #4 along with a low E coating 6a on surface #.
- the benefits of both reduced heat loss and air purification are realised in a single embodiment.
- a low E coating 6a is shown on surface 3 along with a functional coating 6b on surface #1.
- the functional coating 6b could inter alia be a titania coating; an antireflection coating or an anti-condensation coating.
- the invention may employ a sheet of tinted glass 2a as the inner sheet 1 of the IGU 7.
- Tinted glass may be realised as a glass having a higher iron content. Tinted glasses are well known to those skilled in the art and typically contain more than 0.15wt%Fe. The ratio of Fe 2+ /Fe 3+ varies and other additives may also be varied.
- the tinted glass 2a absorbs more energy from the solar radiation causing it to become heated. This heat may be transferred to the air in the cavity 1 by re-radiation or conduction.
- the benefits of using a tinted glass are enhanced when used in conjunction with a low E coating 6a, particularly on surface #3, which inhibits re-radiation of the absorbed energy away from the cavity 1.
- Apparatus according to the invention may also include a transpired solar collector comprising a perforated sheet, arranged to absorb energy from solar radiation and cause warming of the air in the vicinity of its surface.
- the cavity is divided into two regions la and lb by a transpired solar collector panel 11.
- the collector panel 11 is arranged to absorb energy from solar radiation causing its temperature to rise. This, in turn gives rise to heating of the air in the immediate vicinity of the collector.
- a negative pressure is applied to region lb of the cavity, via outlet aperture 5, by means not shown (for example an extractor fan) and this causes warmed air to pass through the perforations (holes) in collector 11 from region la to region lb.
- the warmed air is then directed as described previously for the functions of space heating or heat storage.
- the glazing 2 enhances the effectiveness of the apparatus by the greenhouse effect as previously described.
- a low iron glass such as Pilkington OptiwhiteTM is preferred as this increases the effectiveness of the glazing in this regard.
- the glazing prevents dispersal of the warmed air by wind so that it is able to pass through the transpired solar collector panel 11 undisturbed.
- the single glazed system illustrated in figure 9 preferably includes a coating 6 on the glazing.
- a low-E coating is used, further to reduce heat loss by radiation from the cavity region lb to the external environment.
- the coating 6 comprises a titania coating to provide purified air as described previously.
- the transpired solar collector may also be used in conjunction with an IGU.
- the IGU offers a number of options in terms of surfaces to which various coatings might be applied.
- Figure 10 illustrates embodiments of the invention in which a transpired solar collector panel 11 is combined with an IGU.
- Surface #4 of the IGU bears a coating 6, which in one embodiment is a low E coating.
- coating 6 comprises a titania coating.
- a low E coating 6a is applied to surface #3 of the IGU.
- FIG 12 an embodiment is shown which employs a transpired solar collector panel 11; a low E coating 6a is applied to surface #3 of the IGU 7 to reduce heat loss and a titania coating 6b is applied to surface #4 in order to provide purified air.
- the IGU 7 has a low E coating on surface #3 and a functional coating 6b on surface #1.
- Functional coating 6b could be an antireflective coating, a titania coating or an anticondensation coating.
- the invention may employ a transpired solar collector panel 11 and an IGU 7 in which one of the glass sheets 2a is tinted. As before, the tinted glass has a greater ability to absorb solar radiation which may then be transferred to the air in cavity as heat and a low E coating is preferably applied to surface #3 of the IGU 7, to reduce radiation of heat away from the cavity.
- a glazing which has a 'U' shaped profile, that is it comprises a major sheet 2a (which corresponds to the flat glazing 2 shown in previous embodiments) along with integral glass sidewalls 2b.
- a glazing along with the wall of the building or insulating panel 3 defines the cavity within which air is warmed by solar radiation.
- Such a glazing may be provided as Pilkington ProfileitTM linear channel glass.
- the 'U' profiled glazing may be used in conjunction with a transpired solar collector panel 11 which, as in previous embodiments, divides the cavity into regions la, where the air is warmed, and lb, from where the warmed air is drawn after passing through the transpired solar collector.
- the cavity 1 may be defined by two glazing sheets having a 'U' profile.
- the major sheet 2a of one glazing sheet faces the external environment and allows solar radiation to enter the cavity while the major sheet 3a of the other glazing provides the back wall of the cavity.
- Glazing systems employing Pilkington ProfilitTM in this manner are commercially available.
- various surfaces of the glazings may be coated.
- inner surface of major sheet 3a may include a low e coating.
- use of a low iron glass will facilitate greater transmission of solar radiation to the cavity.
- Pilkington ProfilitTM is commercially available in a low e glass (Pilkington OptiwhiteTM).
- apparatus used to test the effectiveness of various embodiments of the invention comprised: a glazed cavity assembly as generally illustrated in figures 1 - 8, further provided with air inlet and outlet ducts 12 and 13 respectively, a fan 14 located in the outlet duct and arranged to draw air through the cavity 1 and a thermocouple 15 arranged to measure the temperature of the air after it passed through the cavity 1.
- Figure 19 shows a similar arrangement to that in figure 18, except that a glazed cavity with transpired solar collector as generally illustrated in figures 9 - 14 was being tested.
- the coated surface 6 is shown on the 'interior' of the cavity but these figures are examples only and in some cases arrangements were used where the coated surface was on the 'exterior' .
- the air flow was maintained at a linear velocity of about lm/s which, for the apparatus used, equates to a volumetric flow of about 3.3 x 10 "3 m 3 /s.
- thermocouple 15 A comparison of the air temperature, as measured by thermocouple 15, with the ambient (inlet) air temperature provides a measure of the effectiveness of the glazed cavity for warming air.
- Table 1 shows the coating stacks associated with each of the coatings used (all thicknesses in nm). The coated stacks were tested on a simple glazed cavity (figure 18) and data were also obtained using an unglazed transpired solar collector and a glazed solar collector having uncoated soda-lime silica glass (i.e. as illustrated in figure 19 but with no coating 6).
- Table 1 Description of various coated products tested on glazed solar collector.
- Figure 20 shows the air temperature rise obtained for each of the solar collector arrangements indicated.
- the data show that even the combination of an uncoated glazing with the transpired solar collector produces a heating effect that is significantly greater than that offered by either of these features alone.
- the uncoated glazing offers some benefit by collecting and storing solar energy by a straightforward 'greenhouse' effect but also protects the Transpired Solar Collector from the effects of ambient wind.
- warmed air in the vicinity of the Transpired Solar Collector (in cavity la of, e.g. figure 9), may be dispersed by the wind before passing through the Transpired collector, when a glazing is not present.
- a much greater benefit is obtained by use of a coated glazing.
- the horizontal axis in figure 21 represents temperature gain achieved by an uncoated glazed solar collector having no transpired solar collector panel (i.e. a glazed cavity).
- the vertical axis represents the temperature gain achieved by each of the configurations described at the same point in time as the corresponding value on the horizontal axis was measured.
- the coating used on both the single and double glazed cavities was an anticondensation coating produced by Pilkington Group Limited, whose composition is also indicated in table 1.
- Figure 21 shows that all of these configurations provide superior performance to an uncoated glazed collector (by virtue of the positive slopes of all plots); a single coated glazed cavity provides superior result to an unglazed Transpired Solar Collector and a further increase, of about 6%, when the cavity is double glazed.
- DGU double glazed unit
- Table 2 further illustrates the effect of the invention in providing heated air for space heat heating and heat storage.
- Numbers 5 and 7 of each series illustrate the improvement that can be achieved by a combination of a coated glazing and a transpired solar collector panel, as compared with a coated glazing only.
- the coated glazed Transpired Solar Collector (number 7) achieved greater temperature increases and efficiencies that the corresponding glazing without transpired solar collector panel (number 7).
- the K Glass S OW #3 DGU and the 22 ohm OW #4GU have been shown to be similar in performance, so the differences between numbers and 7 are attributed to the presence or absence of the transpired solar collector panel.
- W 22 ohm is an anticondensation coating on Pilkington OptiwhiteTM).
Abstract
Solar collector apparatus is described in which solar radiation is collected in a glazed cavity which may also include a transpired solar collector layer. Air warmed in the cavity may be used for space heating within buildings or diverted to heat management systems which facilitate, for example, heat storage. The glazing, particularly coated glazings, improve the performance of the devices by allowing solar energy to enter the cavity and preventing heat loss, and by negating the effect of ambient wind on the transpired solar collector layer.
Description
Glazed Solar Collectors
The invention concerns apparatus and method for collecting solar radiation and converting same to a form of energy suitable for space heating in buildings.
The use of passive solar energy to heat buildings is well known. In September 1881, E S Morse obtained US Patent No. 246, 626 for "Warming and Ventilation Apartments by the Sun's Rays" and the general concept of warming air beneath a glazing, before directing the warmed air to the interior of the building to provide space heating, has been developed during the intervening years. So called "Trombe Walls" typically comprise a glazing which is arranged in spaced apart relation with a building wall to define a heated cavity. Air enters the cavity via one or more vents near its bottom and is warmed by solar radiation which causes it to rise and exit the cavity via a vent to the interior of the building.
WO 2010/086126 discloses another approach to building heating using solar energy. In this document the solar collector comprises a collector panel which defines an at least partially enclosed space. The collector panel, known as a transpired solar collector, comprises energy absorbing sides, air-inlet openings connecting the outside environment with the at least partly enclosed space and an air-outlet duct connected to the at least partly enclosed space. Solar energy is absorbed by the energy absorbing sides and this causes heating of air in the outside environment, in the immediate vicinity of the panel.
A negative pressure is applied to the air-outlet duct and this causes the warmed air to pass through the air-inlet openings, through the at least partially enclosed space and out of the air-outlet duct, from where it is directed to the point of use in space heating, or heat storage. WO 2010/086126 also describes systems for storing and managing the heat derived from the panels. The effectiveness of the apparatus described in WO 2010/086126 is affected by wind which disturbs the warmed air in the vicinity of the panel, before it passes through the inlet openings.
Chinese Utility Model No. eN 201517854 U describes another system in which air, warmed by solar radiation, is used for space heating. Again, a panel is disclosed, with holes through which warmed air passes and is recovered for building heating. The apparatus also includes a glazing, arranged in parallel spaced relationship with the panel so that air between the glazing and the panel is warmed by solar radiation before being passing through the holes. A glazing comprising glass having a high iron content is recommended because such glass absorbs solar radiation more effectively, better to heat the air between the glazing and the panel.
The requirement for ever improving means for collecting solar energy remains. The present invention provides such means, whereby solar energy is collected with a high degree of efficiency and made available for uses such as internal space heating in buildings or heat storage and management e.g., according to the methods described in WO 2010/086126.
According to the invention, apparatus for collecting solar energy comprises: a cavity, a glazing, arranged to allow solar radiation to pass therethrough and enter the cavity, an inlet aperture, arranged to allow air to enter the cavity from an external environment and an outlet aperture, arranged to allow air warmed by the solar radiation, to exit the cavity; characterised in that the glazing comprises a coated glass. The coating may comprises a low emissivity coating, a pyrolytically deposited fluorine doped tin oxide a titania coating or an antireflection coating.
In embodiments comprising a single glazing sheet, the coating is located on either the internal surface, or the external surface of the glass, relative to the cavity.
In one embodiment, the glazing comprises a major sheet and has integral glass sidewalls. Two glazings may be employed, each glazing comprising a major sheet and two integral glass sidewalls, and the glazings being arranged to define the cavity therebetween.
The apparatus may include an Insulated Glazing Unit (IGU), said IGU comprising at least two glass sheets. The IGU may comprise two glass sheets wherein the coating is located on surface #4 of the IGU. The coating on surface #4 of the IGU may comprise titania or pyrolytically deposited fluorine doped tin oxide.
Alternatively, the IGU may comprise two glass sheets wherein the coating is a low E coating located on surface #3 of the IGU. This coating may be the product of a sputter deposition process and may comprise silver or a compound of silver.
Alternatively, the coating may be located on surface #1 of the IGU and may comprise an antireflection coating, a titania coating or a pyrolytically deposited fluorine doped tin oxide.
The IGU may include a glass sheet comprising a tinted glass. Typically, the tinted glass would have a composition comprising at least 0.15wt% iron.
The apparatus may include at least one sheet of glass comprises a low iron content glass, having an iron content of less than 0.02wt%, preferably less than 0.015wt% most preferably less than 0.01wt%.
The apparatus may include a transpired solar collector arranged to divide the cavity into first and second regions, the first region being bounded by the glazing wherein the collector comprises a sheet of material having a plurality of holes, the holes providing communication between the two regions,
and wherein the inlet aperture is arranged to allow air to enter the first region and the outlet aperture is arranged to allow air to leave the second region.
Where the apparatus includes a titania coating on the innermost glass surface relative to the cavity, means may be included for directing a flow of water on to said surface.
According to a second aspect of the invention, apparatus for collecting solar energy comprises: a cavity, a glazing, arranged to allow solar radiation to pass therethrough and enter the cavity, an inlet aperture, arranged to allow air to enter the cavity from an external environment and an outlet aperture, arranged to allow air warmed by the solar radiation, to exit the cavity; characterised in that the glazing comprises a low iron glass.
Preferably, the glass comprises less than 0.02wt% iron, more preferably less than 0.015wt% iron and even more preferably, less than 0.01wt% iron.
The invention will now be further described using non-limiting examples, with reference to the attached figures in which:
Figures 1 - 3 illustrate various embodiments of the invention employing a single glazing on a simple undivided cavity;
Figures 4 - 8 illustrate various embodiments of the invention employing a multiple glazing on a simple undivided cavity;
Figures 9 - 14 illustrate various embodiments of the invention in which the cavity is divided by a transpired solar collector;
Figure 15 illustrates apparatus according to the invention in which a glazing having a 'U' shaped cross-sectional profile is employed; Figure 16 illustrates apparatus employing a glazing having a 'U' shaped cross-sectional profile wherein the cavity is divided by a transpired solar collector and
Figures 17a and 17b illustrate embodiments wherein two glazings having a 'U shaped cross-sectional profile are used to define the cavity.
Figures 18 and 19 illustrate a test apparatus used to evaluate the performance of glazed solar collectors according to the invention both with and without a Transpired Solar Collector sheet; Figure 20 shows the performance of various embodiments of the invention in terms of rise in air temperature achieved for a given solar radiation and
Figure 21 shows the improvement in performance over a simple uncoated glazed cavity that may be achieved by various embodiments of the invention.
Referring to figure 1, a first embodiment of the invention includes a cavity 1 which is partly defined by a glazing 2. The cavity further comprises side walls (not shown) parallel to the plane of the page and may be arranged against the wall of a building which serves as another wall of the cavity. Alternatively, an insulated panel 3, which may be fixed to the exterior of a building, may serve as the back wall of the cavity. Examples of insulated panels which might serve this purpose include Trisomet® 333 manufactured by Tata Steel.
During operation, cold air enters the cavity via a lower aperture 4, is warmed by solar radiation passing through the glazing and then exits cavity via an upper aperture 5. After exiting the cavity, the warmed air may be directed to the interior of a building to provide space heating or the heat may be extracted for storage or other use by means well known to persons skilled in the art.
Warming of the air in the cavity 1 is aided by the so-called greenhouse effect, whereby solar radiation passes through the glazing and is absorbed by the interior of the cavity to cause heating. The glazing is less transmissive to infrared radiation associated with this heating and hence inhibits heat loss. A low iron glass such as Pilkington Optiwhite™ may be used for the glazing as this further reduces the amount of solar energy absorbed by the glass and facilitates transmission of energy to the cavity. Preferably, the low iron glass comprises <0.02wt% iron, more preferably <0.015wt% and most preferably <0.010wt%.
In various embodiments of the invention, a coating 6 is applied to the inner surface of the glazing.
In one embodiment, the coating 6 comprises a low emissivity (low E) coating (designated 6a in subsequent drawings) which reduces the transmission of infrared radiation. Thus loss of heat through the glazing, from within the cavity, is reduced.
The low E coating is preferably chosen to optimise the trade-off between solar gain and heat trapping by balancing transmission of solar radiation into the cavity against heat loss by infrared radiation from the cavity. In this connection, an optimum sheet resistance of between 15 and 30 ohm per square has been established. Pilkington K Glass™ is a low E glazing material suitable for use in this embodiment of the invention. K Glass™ comprises a fluorine doped tin oxide coating on a colour suppressing silicon oxy carbide coating.
In another embodiment the coating 6 may comprise a functional coating (designated 6b in subsequent drawings) such as titanium dioxide (titania). Titania coatings are known to
offer an antimicrobial effect via a photocatalytic effect, whereby highly reactive free radicals are generated from oxygen and moisture under the influence of ultraviolet radiation in (for example) sunlight. Inclusion of such a coating on the inner surface of the glazing causes decomposition of organic contaminants and killing of microorganisms to provide a purified air supply for the building.
Use of such a coating along with means for irrigating the inner surface of the glazing provides for easy cleaning of the inner glazing surface. Such irrigation means (not shown) typically comprises a water outlet such as a nozzle, array of nozzles or a pipe with one or more holes, connected to a water supply and arranged to direct a flow of water on to the coated surface.
The self-cleaning action is enhanced where a hydrophilic coating is used which causes water droplets to spread on the surface and run off easily.
Pilkington Activ™ is a titania-based self-cleaning glazing which serves in this embodiment.
In general, in all of the embodiments described herein, where a titania-based self-cleaning coating is used on a interior surface of the glass, relative to the cavity, such embodiments may optionally include means for irrigating said inner surface.
Referring to figure 2, in another preferred embodiment, a functional coating 6b is applied to the external surface of the glazing. For example, an antireflective coating increases the effectiveness of the device by increasing the amount of solar radiation which is transmitted through the glazing 2 to provide heading of air in the cavity 1. Pilkington Optiview™ serves as a suitable glazing product in this embodiment.
Alternatively, the functional coating 6b could comprise a self-cleaning coating such as found on Pilkington Activ™ so that the exterior glass surface remains relatively free from contaminants that would otherwise inhibit transmission of solar radiation and adversely affect the visible appearance of the installation. Pilkington Activ™ also offers
anticondensation properties in this orientation as its hydrophilic properties cause water droplets which gather on the outer surface to spread and readily run off.
Anticondensation properties are also achieved using pyrolytically deposited fluorine doped tin oxide based coatings such as found in Pilkington K Glass™ or Energy
Advantage™. These so-called 'hard coatings', which are deposited during the float glass manufacturing process, are highly stable and fused to the glass surface. This makes them suitable for applications where they are exposed to the external environment. Referring to figure 3, the glazing could include coatings on both sides. The inner surface coating 6 could, for example be a low E coating or a titania coating. The coating 6b on the external surface could be a functional coating such as anticondensation, antireflective or self-cleaning. Preferably in this embodiment, the emissivity of the inner coating 6 is less than that of the outer coating 6b.
Referring to figure 4, the invention may include an insulated glazed unit (IGU) 7 of the type well known in the art and comprising two or more glazings 2, 8 held apart by spacers 9 to define a low thermal conductivity gap 10, typically containing air or another gas. In the embodiment shown, a coating 6 is shown on the innermost glass surface which, as in the previous embodiment (figure 1) might be a low E coating or a titania coating. By convention, the glass surfaces are numbered from #1 to #4, number 1 being the outermost (i.e. furthest from the building, contacting the external environment) so in figure 3, the coating 6 is shown on surface #4. When used in this specification, conventional numbers referring to the various glass surfaces are underlined in order to distinguish them from numerals used to identify features in the drawings.
Referring to figure 5, as an alternative to the arrangement shown in figure 3, a low E coating 6a may be located on an internal glass surface with the IGU. In figure 5, the low E coating 6a is shown on surface 3. Since this surface is protected from the elements due to its location within the IGU, a so called 'soft coating' may be
used such as a silver-based sputtered coating of the type known in the art. Pilkington Optitherm™ is an example of a product having such a coating.
Referring to figures 6 and 7, use of a multi-glazed IGU offers a number of options for the application of various coatings to the various surfaces. In figure 6, a functional titania coating 6b is shown on surface #4 along with a low E coating 6a on surface #. Thus, the benefits of both reduced heat loss and air purification are realised in a single embodiment.
In figure 7, a low E coating 6a is shown on surface 3 along with a functional coating 6b on surface #1. The functional coating 6b could inter alia be a titania coating; an antireflection coating or an anti-condensation coating.
Referring to figure 8, the invention may employ a sheet of tinted glass 2a as the inner sheet 1 of the IGU 7. Tinted glass may be realised as a glass having a higher iron content. Tinted glasses are well known to those skilled in the art and typically contain more than 0.15wt%Fe. The ratio of Fe2+/Fe3+ varies and other additives may also be varied. The tinted glass 2a absorbs more energy from the solar radiation causing it to become heated. This heat may be transferred to the air in the cavity 1 by re-radiation or conduction. The benefits of using a tinted glass are enhanced when used in conjunction with a low E coating 6a, particularly on surface #3, which inhibits re-radiation of the absorbed energy away from the cavity 1.
Apparatus according to the invention may also include a transpired solar collector comprising a perforated sheet, arranged to absorb energy from solar radiation and cause warming of the air in the vicinity of its surface.
Referring to figure 9, in one embodiment of the invention, the cavity is divided into two regions la and lb by a transpired solar collector panel 11. The collector panel 11 is arranged to absorb energy from solar radiation causing its temperature to rise. This, in turn gives rise to heating of the air in the immediate vicinity of the collector.
A negative pressure is applied to region lb of the cavity, via outlet aperture 5, by means not shown (for example an extractor fan) and this causes warmed air to pass through the perforations (holes) in collector 11 from region la to region lb. The warmed air is then directed as described previously for the functions of space heating or heat storage.
Inclusion of the glazing 2 enhances the effectiveness of the apparatus by the greenhouse effect as previously described. As before, a low iron glass such as Pilkington Optiwhite™ is preferred as this increases the effectiveness of the glazing in this regard. In addition, the glazing prevents dispersal of the warmed air by wind so that it is able to pass through the transpired solar collector panel 11 undisturbed.
The single glazed system illustrated in figure 9 preferably includes a coating 6 on the glazing. In one embodiment a low-E coating is used, further to reduce heat loss by radiation from the cavity region lb to the external environment. In another embodiment, the coating 6 comprises a titania coating to provide purified air as described previously.
The transpired solar collector may also be used in conjunction with an IGU. As before, the IGU offers a number of options in terms of surfaces to which various coatings might be applied.
Figure 10 illustrates embodiments of the invention in which a transpired solar collector panel 11 is combined with an IGU. Surface #4 of the IGU bears a coating 6, which in one embodiment is a low E coating. In another embodiment, coating 6 comprises a titania coating.
In the embodiment illustrated by figure 11, a low E coating 6a is applied to surface #3 of the IGU.
In figure 12, an embodiment is shown which employs a transpired solar collector panel 11; a low E coating 6a is applied to surface #3 of the IGU 7 to reduce heat loss and a titania coating 6b is applied to surface #4 in order to provide purified air.
In figure 13, the IGU 7 has a low E coating on surface #3 and a functional coating 6b on surface #1. Functional coating 6b could be an antireflective coating, a titania coating or an anticondensation coating. Referring to figure 14, the invention may employ a transpired solar collector panel 11 and an IGU 7 in which one of the glass sheets 2a is tinted. As before, the tinted glass has a greater ability to absorb solar radiation which may then be transferred to the air in cavity as heat and a low E coating is preferably applied to surface #3 of the IGU 7, to reduce radiation of heat away from the cavity.
Referring to figure 15, in another variant of the invention, a glazing is employed which has a 'U' shaped profile, that is it comprises a major sheet 2a (which corresponds to the flat glazing 2 shown in previous embodiments) along with integral glass sidewalls 2b. Such a glazing, along with the wall of the building or insulating panel 3 defines the cavity within which air is warmed by solar radiation.
Utilisation of a glazing having integral glass sidewalls allows for more solar energy to enter the cavity. Such a glazing may be provided as Pilkington Profilit™ linear channel glass.
Referring to figure 16, the 'U' profiled glazing may be used in conjunction with a transpired solar collector panel 11 which, as in previous embodiments, divides the cavity into regions la, where the air is warmed, and lb, from where the warmed air is drawn after passing through the transpired solar collector.
Referring to figure 17a and 17b, the cavity 1 may be defined by two glazing sheets having a 'U' profile. In use, the major sheet 2a of one glazing sheet faces the external environment and allows solar radiation to enter the cavity while the major sheet 3a of the other glazing provides the back wall of the cavity.
Glazing systems employing Pilkington Profilit™ in this manner are commercially available.
As in other embodiments, various surfaces of the glazings may be coated. For example, inner surface of major sheet 3a may include a low e coating. Also, use of a low iron glass will facilitate greater transmission of solar radiation to the cavity. Pilkington Profilit™ is commercially available in a low e glass (Pilkington Optiwhite™).
Example 1
Referring to figures 18, apparatus used to test the effectiveness of various embodiments of the invention comprised: a glazed cavity assembly as generally illustrated in figures 1 - 8, further provided with air inlet and outlet ducts 12 and 13 respectively, a fan 14 located in the outlet duct and arranged to draw air through the cavity 1 and a thermocouple 15 arranged to measure the temperature of the air after it passed through the cavity 1.
Figure 19 shows a similar arrangement to that in figure 18, except that a glazed cavity with transpired solar collector as generally illustrated in figures 9 - 14 was being tested.
During testing, a plurality of assemblies as illustrated in figures 18 and 19, and each with a different surface coating 6, were arranged side by side with the glazing facing substantially in the direction of sunlight.
N.B. In figures 18 and 19, the coated surface 6 is shown on the 'interior' of the cavity but these figures are examples only and in some cases arrangements were used where the coated surface was on the 'exterior' . The air flow was maintained at a linear velocity of about lm/s which, for the apparatus used, equates to a volumetric flow of about 3.3 x 10"3m3/s.
A comparison of the air temperature, as measured by thermocouple 15, with the ambient (inlet) air temperature provides a measure of the effectiveness of the glazed cavity for warming air.
Table 1 shows the coating stacks associated with each of the coatings used (all thicknesses in nm). The coated stacks were tested on a simple glazed cavity (figure 18) and data were also obtained using an unglazed transpired solar collector and a glazed solar collector having uncoated soda-lime silica glass (i.e. as illustrated in figure 19 but with no coating 6).
Table 1: Description of various coated products tested on glazed solar collector. Figure 20 shows the air temperature rise obtained for each of the solar collector arrangements indicated. The data show that even the combination of an uncoated glazing with the transpired solar collector produces a heating effect that is significantly greater than that offered by either of these features alone. The uncoated glazing offers some benefit by collecting and storing solar energy by a straightforward 'greenhouse' effect but also protects the Transpired Solar Collector from the effects of ambient wind. As previously noted, warmed air, in the vicinity of the Transpired Solar Collector (in cavity la of, e.g. figure 9), may be dispersed by the wind before passing through the Transpired collector, when a glazing is not present. However, a much greater benefit is obtained by use of a coated glazing.
The Pilkington K Glass™ on Optiwhite™ produced the most significant increase in air temperature. Without wishing to be bound by theory, it is believed that these coatings showing best performance offer the optimum compromise between the need to allow solar radiation to pass therethrough and enter the cavity, and the need to retain the heat in
the cavity once it has been captured. (N.B. TEC 15 R refers to the TEC 15 product being used in 'reverse orientation' i.e. the coated surface was on the outside of the cavity).
Example 2
Referring to figure 21, a further experiment was performed to compare the performance of a coated single glazing; a double glazed unit having a coating on surface #3 and an unglazed Transpired Solar Collector, with that of an uncoated glazed solar collector, having no transpired collector. The upper plot shows the performance of the double glazed simple cavity (figure 18 with double glazed unit); the middle plot shows that of the single glazed simple cavity (figure 18) and the lower plot shows the performance of the unglazed Transpired Solar Collector.
The horizontal axis in figure 21 represents temperature gain achieved by an uncoated glazed solar collector having no transpired solar collector panel (i.e. a glazed cavity). The vertical axis represents the temperature gain achieved by each of the configurations described at the same point in time as the corresponding value on the horizontal axis was measured. Thus, the greater the slope of the graph, the better the performance of the configuration in question. The coating used on both the single and double glazed cavities was an anticondensation coating produced by Pilkington Group Limited, whose composition is also indicated in table 1.
Figure 21 shows that all of these configurations provide superior performance to an uncoated glazed collector (by virtue of the positive slopes of all plots); a single coated glazed cavity provides superior result to an unglazed Transpired Solar Collector and a further increase, of about 6%, when the cavity is double glazed.
Example 3
Table 2 below summarises a further set of experiments performed using various embodiments of the invention.
Test Airflow Average Average Efficiency Glazing Number Ducting Temp Irradience
Increase
Series 1
1 0.3 23.7 850 0.19 K Glass OW
#3 DGU
2 0.57 23.7 850 0.37 K Glass OW
#3 DGU
3 0.62 27.7 850 0.47 22 ohm OW #3
DGU
4 0.7 18.9 850 0.36 22 ohm OW #3
DGU
5 1.03 15.4 850 0.43 K Glass S OW
#3 DGU (glazed without TSC)
6 9.6 850 0.00
7 1.09 19.2 850 0.57 22 ohm OW #4
DGU (glazed with TSC)
8 1.14 11.4 850 0.35 22 ohm OW #4
DGU (wide gap)
Series 2
1 0.3 15.2 621 0.17 K Glass OW
#3 DGU
2 0.57 14.8 621 0.31 K Glass OW
#3 DGU
3 0.62 5.4 621 0.36 22 ohm OW #3
DGU
4 0.7 12.9 621 0.34 22 ohm OW #3
DGU
5 1.03 9.9 621 0.38 K Glass S OW
#3 DGU (glazed without TSC)
6 8.7 621 0.00
7 1.09 14.2 621 0.58 22 ohm OW #4
DGU (glazed with TSC)
8 1.14 9.5 621 0.40 22 ohm OW #4
DGU (wide gap)
(Additional Data:
Ducting diameter 0.075 0.075 vol flow at lm/s 0.004415625 0.004415625 density of air 1.2 1.2 mass of air flow 0.00529875 0.00529875
Power required to raise temp by
1C 5.3305425 5.3305425 specific heat capacity of air 1.006 1.006 area of solar collector panel 0.23 0.23)
#3, #4 etc = surface 3, surface 4 etc;
DGU = double glazed unit;
OW = Optiwhite™
Table 2 further illustrates the effect of the invention in providing heated air for space heat heating and heat storage.
Numbers 5 and 7 of each series illustrate the improvement that can be achieved by a combination of a coated glazing and a transpired solar collector panel, as compared with a coated glazing only. In both series, the coated glazed Transpired Solar Collector (number 7) achieved greater temperature increases and efficiencies that the corresponding glazing without transpired solar collector panel (number 7).
this regard it should be noted that the K Glass S OW #3 DGU and the 22 ohm OW #4GU have been shown to be similar in performance, so the differences between numbers and 7 are attributed to the presence or absence of the transpired solar collector panel. W 22 ohm is an anticondensation coating on Pilkington Optiwhite™).
Claims
1. Apparatus for collecting solar energy comprising: a cavity, a glazing, arranged to allow solar radiation to pass therethrough and enter the cavity, an inlet aperture, arranged to allow air to enter the cavity from an external environment and an outlet aperture, arranged to allow air warmed by the solar radiation, to exit the cavity; characterised in that the glazing comprises a coated glass.
2. Apparatus according to claim 1, wherein the coating comprises a low emissivity coating.
3. Apparatus according to claim 2, wherein the coating comprises pyrolytically deposited fluorine doped tin oxide.
4. Apparatus according to claim 1, wherein the coating comprises a titania coating.
5. Apparatus according to claim 3 or 4, wherein the coating is located on the internal surface of the glass, relative to the cavity.
6. Apparatus according to claim 3 or 4, wherein the coating is located on the external surface of the glass, relative to the cavity.
7. Apparatus according to claim 1, wherein the coating comprises an antireflection coating.
8. Apparatus according to claim 1, comprising an Insulated Glazing Unit (IGU), said IGU comprising at least two glass sheets.
9. Apparatus according to claim 8, wherein the IGU comprises two glass sheets and the coating is located on surface 4 of the IGU.
10. Apparatus according to claim 9, wherein the coating comprises titania.
11. Apparatus according to claim 9, wherein the coating comprises pyrolytically deposited fluorine doped tin oxide.
12. Apparatus according to claim 8, wherein the IGU comprises two glass sheets and the coating is a low E coating located on surface 3 of the IGU.
13. Apparatus according to claim 12, wherein the coating is the product of a sputter deposition process.
14. Apparatus according to claim 13, wherein the coating comprises silver or a compound of silver.
15. Apparatus according to claim 8, wherein the coating is located on surface 1 of the IGU.
16. Apparatus according to claim 15, wherein the coating comprises an antireflection coating.
17. Apparatus according to claim 15, wherein the coating comprises a titania coating.
18. Apparatus according to claim 15, wherein the coating comprises pyrolytically deposited fluorine doped tin oxide.
19. Apparatus according to claim 8, wherein at least one glass sheet comprises a tinted glass.
20. Apparatus according to claim 19, wherein the tinted glass has a composition comprising at least 0.15wt% iron.
21. Apparatus according to any preceding claim, wherein at least one sheet of glass comprises a low iron content glass, having an iron content of less than 0.02wt%, preferably less than 0.015wt% most preferably less than 0.01wt%.
22. Apparatus according to any of claims 1 - 7, wherein the glazing comprises a major sheet and has integral glass sidewalls.
23. Apparatus according to any preceding claim, wherein the cavity is divided into first and second regions by a transpired solar collector, the first region being bounded by the glazing, said collector comprising a sheet of material having a plurality of holes, the holes providing communication between the two regions, and wherein the inlet aperture is arranged to allow air to enter the first region and the outlet aperture is arranged to allow air to leave the second region.
24. Apparatus according to claim 4 or 10, or claim 23 when dependent on either of claims 4 or 10, and further comprising means for directing a flow of water on to the titania coated glass surface.
25. Apparatus according to claim 22, comprising two glazings, each glazing comprising a major sheet and two integral glass sidewalls, the glazings arranged to define the cavity therebetween.
26. Apparatus for collecting solar energy comprising:
a cavity, a glazing, arranged to allow solar radiation to pass therethrough and enter the cavity, an inlet aperture, arranged to allow air to enter the cavity from an external environment and an outlet aperture, arranged to allow air warmed by the solar radiation, to exit the cavity; characterised in that the glazing comprises a low iron glass.
27. Apparatus according to claim 26, comprising glass comprises less than 0.02wt% iron.
28. Apparatus according to claim 27, comprising glass comprises less than 0.015wt% iron.
29. Apparatus according to claim 28, comprising glass comprises less than 0.01wt% iron.
Applications Claiming Priority (2)
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GBGB1407814.1A GB201407814D0 (en) | 2014-05-02 | 2014-05-02 | Glazed solar collectors |
PCT/GB2015/051314 WO2015166291A1 (en) | 2014-05-02 | 2015-05-05 | Glazed solar collectors |
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EP (1) | EP3137820A1 (en) |
AU (1) | AU2015255032A1 (en) |
CA (1) | CA2947653A1 (en) |
GB (1) | GB201407814D0 (en) |
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Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2003048655A1 (en) * | 2001-12-01 | 2003-06-12 | Christensen Hans Joergen | Solar collector panel for heating ventilation air |
Family Cites Families (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4262657A (en) * | 1976-08-06 | 1981-04-21 | Union Carbide Corporation | Solar air heater |
GB1584764A (en) * | 1977-05-27 | 1981-02-18 | Bfg Glassgroup | Solar collector |
US4161170A (en) * | 1977-11-17 | 1979-07-17 | Olin Corporation | Solar energy collection system |
US6998362B2 (en) * | 1993-02-04 | 2006-02-14 | Pilkington Plc | Glass compositions |
FR2752570B1 (en) * | 1996-08-22 | 1998-10-02 | Saint Gobain Vitrage | GLAZING WITH VARIABLE OPTICAL AND / OR ENERGY PROPERTIES |
US20020136905A1 (en) * | 1999-11-24 | 2002-09-26 | Medwick Paul A. | Low shading coefficient and low emissivity coatings and coated articles |
US7192897B2 (en) * | 2002-07-05 | 2007-03-20 | Hoya Corporation | Near-infrared light-absorbing glass, near-infrared light-absorbing element, near-infrared light-absorbing filter, and method of manufacturing near-infrared light-absorbing formed glass article, and copper-containing glass |
EP1644293B2 (en) * | 2003-07-11 | 2022-04-13 | Pilkington Group Limited | Solar control glazing |
GB0415046D0 (en) * | 2004-07-05 | 2004-08-04 | Micromass Ltd | Mass spectrometer |
US9200818B2 (en) * | 2009-08-14 | 2015-12-01 | Newdoll Enterprises Llc | Enhanced solar panels, liquid delivery systems and associated processes for solar energy systems |
US20130042902A1 (en) * | 2010-02-09 | 2013-02-21 | The University Of Western Ontario | Hybrid solar energy conversion system with photocatalytic disinfectant layer |
FR2988466B1 (en) * | 2012-03-22 | 2014-04-11 | Sunpartner | SOLAR ENERGY SENSOR TRANSPARENT |
ES2455815B1 (en) * | 2012-10-16 | 2015-01-20 | Fundación Tekniker | Solar thermal collector device |
-
2014
- 2014-05-02 GB GBGB1407814.1A patent/GB201407814D0/en not_active Ceased
-
2015
- 2015-05-05 RU RU2016147171A patent/RU2016147171A/en not_active Application Discontinuation
- 2015-05-05 WO PCT/GB2015/051314 patent/WO2015166291A1/en active Application Filing
- 2015-05-05 CA CA2947653A patent/CA2947653A1/en not_active Abandoned
- 2015-05-05 US US15/307,860 patent/US20170051948A1/en not_active Abandoned
- 2015-05-05 AU AU2015255032A patent/AU2015255032A1/en not_active Abandoned
- 2015-05-05 SG SG11201608672QA patent/SG11201608672QA/en unknown
- 2015-05-05 EP EP15722747.1A patent/EP3137820A1/en not_active Withdrawn
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2003048655A1 (en) * | 2001-12-01 | 2003-06-12 | Christensen Hans Joergen | Solar collector panel for heating ventilation air |
Also Published As
Publication number | Publication date |
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US20170051948A1 (en) | 2017-02-23 |
AU2015255032A1 (en) | 2016-11-03 |
CA2947653A1 (en) | 2015-11-05 |
GB201407814D0 (en) | 2014-06-18 |
RU2016147171A (en) | 2018-06-05 |
SG11201608672QA (en) | 2016-11-29 |
WO2015166291A1 (en) | 2015-11-05 |
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