How do passive solar collectors work?
A. Passive systems can be divided into two types: Thermosiphon and Integral Collectors Storage (ICS). Passive solar systems are popular because of their inherent simplicity and reliability. The storage tank is located on the roof and heating effect of the sun causes warm water to circulate within it. Cold water from the city flows directly to the tank on the roof, and then flows to a conventional water heater located on the ground level. It is desirable to keep the distance between the solar system and ground level water heater as short as possible in order to reduce the amount of cold water sitting in the pipe between the two units. In the case of a thermosiphon system, an insulated tank will prevent the loss of stored heat during the night. The ICS or “batch” heater is the most simple kind of solar heater, but the exposure of the storage unit to night air can cause significant heat loss in winter and precludes the use of this kind of panel in all but the mildest climates.
