How do active solar collectors work?
A. The collector is usually an all copper tube and fin absorber enclosed with an insulated aluminum frame or “box”, covered with a low-iron tempered glass glazing. The water contained within the gas or electric water heater is circulated through the solar panels in a single-tank system, or a separate tank is used to pre-heat the water before it enters the conventional water heater in a two-tank system. A two tank system is usually considered to be the best option but if properly managed, a single tank system can provide between 50 and 80% of the household needs for hot water. The water being circulated is gradually heated and the system should be sized to provide between fifteen to twenty-five gallons of hot water per person per day. A reliable automatic control to operate the pump is essential. Fortunately, pumps and electronic controls have evolved and can be expected to provide over twenty years (and counting!) of service.
