For simplicity, we have assumed the solar collector for pool or spa heating is an Aquatherm Model SI-11001. This is an UNglazed (no glass cover) collector with 3.72 square-meters of surface area.
For Spa sizes less than 5 sq-meters, we assume one panel will be used. For pool sizes less than 24 sq-meters we assume 3 panels will be used. And, for pool sizes from 25-80 sq-meters we assume 8 panels will be used.
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