Solar Collector Construction

The type of solar collector proposed shall be compatible with the proposed system type.   Collectors shall be selected based on optimal cost and performance.  Depending on the temperature requirements of the system, collector may be unglazed (low temperature), single or double glazed (mid temperature), or evacuated tube (high temperature) with selective or painted absorber surfaces.  Furnish collectors of weather-tight construction and with an aluminum casing.  Provide aluminum or stainless steel mounting brackets and hinges.  Furnish stainless steel assembly hardware including all bolts, washers, and nuts.  Install collectors such that tubes on the absorber plate drain by gravity.  Provide cover glazing completely replaceable from the front of the collector without disturbing the piping or adjacent collectors. 

Collector Warranty
Provide a minimum 3-year warranty against the following:  failure of manifold or riser tubing, joints or fittings; degradation of absorber plate selective surface; rusting or discoloration of collector hardware; and embrittlement of header manifold seals.  Include with the warranty full repair or replacement of defective materials or equipment.

Solar Collector Performance

Plot thermal performance on the thermal efficiency curve in accordance with ASHRAE 93 showing the product of glazing tranmittance and plate aborptivity and also the thermal loss coefficient (btu/hr/F) of the solar collector.   Show manufacturer's recommended volumetric flow rate and the design pressure drop at the recommended flow rate.  Indicate the manufacturer's recommendations for the number of collectors to be joined per bank while providing for balanced flow and for thermal expansion considerations.