Drainback Solar Thermal Systems
If you think a drainback solar hot water system fits your needs, you must consider a wide variety of rules, limitations and requirements, as outlined below.
Array choice and mounting
The choice of collector array for drainback systems is more complicated than for a pressurized system: some evacuated tube collectors cannot be used at all (check with the manufacturer) and any collectors that use serpentine riser tubes are also ruled out.