Size a solar thermal collector array for domestic hot water based on demand, location, and collector efficiency.
Input Parameters
Results
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Daily Heat Required
BTU
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Collector Area
ft²
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Collectors (4x8)
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Solar Fraction
%
Note: Target 60-80% solar fraction for DHW systems. Oversizing wastes money; undersizing needs more backup heating.
Reference
Heat Required = Gallons x 8.34 lb/gal x (T_hot - T_cold) [BTU]
Collector Area = Heat Required / (Radiation x Efficiency)
Num Collectors = ceil(Area / 32 ft² per 4x8 panel)
Solar Fraction = Actual Collection / Heat Required