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The Solarwall® is a patented system which provides heating for large buildings. The Solarwall uses transpired solar collectors as a building cladding for solar preheating of intake air. Not only does this system provide free heating of intake air, it also functions to improve the overall distribution and quality of indoor air. The Solarwall can preheat intake air by as much as 30° C (54° F), for a reduction in annual heating costs of up to $60 per square meter of wall. Indoor air quality can be improved by the continuous introduction of fresh outside air. Other benefits of the Solarwall include: low capital cost; no maintenance; destratification of ceiling heat; recapture of night time heat loss; elimination of drafts and negative air pressure; and summer cooling. The Solarwall can be retrofitted on existing structures and specified for new ones. Figures 1 and 2 show a residential and an industrial application of the Solarwall.
Figure 1: The Ministry of Housing, Windsor, Ontario, Canada
Figure 2: The Ford Oakville Assembly Plant, Oakville, Ontario, Canada
Solarwall cladding can be installed on new buildings requiring heated air, and on existing high rise, commercial and industrial buildings. The Solarwall panels replace conventional wall cladding yet have the appearance of a typical metal wall. The system has been installed on numerous buildings for Ford, General Motors, McDonnell Douglas, Bombardier and others. Newer applications include residential heaters, schools, solar crop drying in Third World countries and preheating combustion air for co-generation plants. Solarwall cladding is made of either aluminum or galvanized steel and can be fashioned for most conventional building profiles. The wall coating can be any dark colour - the darker the colour, the more heat that is absorbed. Some Solarwall specifications are given in Table 1.
OPERATING EFFICIENCY: UP TO 75% ESTIMATED R-VALUE: 50 ANNUAL ENERGY SAVINGS: $ 10 - $ 60/m² ESTIMATED PAYBACK PERIOD 1 NEW: 1-3 YEARS 1 Based on vendor calculations |
Figure 3 shows an operating schematic of the Solarwall. The cladding is installed on a south-facing wall and heats up when exposed to the sun. Ventilation fans at the top of the wall create a negative pressure which cause air to be drawn through holes along the wall. As the air passes through the wall cavity it is warmed by the heated panels. The heated air is drawn up to the top of the wall, collected in the Solarwall's canopy plenum and ducted to the nearest fan. These fans will then distribute the heated air throughout the building. Any building heat loss is also recaptured by the incoming air and is returned to the building. The Solarwall also provides summer cooling by preventing normal solar radiation from striking the building's main wall. Hot air is thermally siphoned up the wall and ventilated through holes at the top of the cladding, leaving the main wall cool. By-pass dampers allow non-preheated air to be drawn directly into the building, maintaining indoor air quality. Figure 4 shows air temperature rise vs. solar radiation for various air-flow rates (A, B, C, D, E) through the Solarwall. For example, on a sunny day the solar radiation would be about 900 watts per square metre. With a flow rate of 7 cfm/ft² (E), the temperature rise would be approximately 16° C; with a flow rate of 1 cfm/ft² (A), the temperature rise would be almost 40° C.
Figure 3: The Solarwall Operating Schematic
Figure 4: Air-Temperature rise vs. Solar radiation for various air-flow rates
Conserval Engineering Inc. is based in Toronto and is engaged in the design, manufacturing, distribution and installation of energy saving products and systems. Conserval was incorporated in 1977 and the Solarwall has since become its flagship product. All of Conserval's products are sold through its wholly-owned U.S. subsidiary, Conserval Systems Inc., which has offices in Buffalo, NY. Conserval can provide several levels of service including a turnkey installation, materials and system design. The Solarwall panels are now being marketed as a building material to be specified by architects, engineers and contractors. The Solarwall has received awards from Popular Science Magazine, R&D Magazine, the US Department of Energy, and Canmet, among others. Some of Conserval's other products include air make-up fans, industrial humidification systems and heat-recovery systems.
Profile Print Date: 10/95
Catalogue # 08-002
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