Cars with dark seats are good examples of how the absorbers in solar collectors work. When solar energy passes through the windows of a car, heat is absorbed by the seat. If the seats were a lighter color, like yellow or white, light would be reflected away from the seats, and less heat would be absorbed. Dark-colored seats absorb more heat. Insulation Heat always tries to move from a hotter object to a colder one.
Insulation is what prevents or slows down the movement of heat.
Because insulation prevents the heat inside a solar collector from moving to the outside where the temperature is lower, it is an important part of any solar collector. When a solar collector is working properly, the heat that it produces moves from the collector to an area where that heat can be used. If the collector's job is to heat water, then pipes, tubes, and pumps move water from the collector to water heating or space heating equipment. When fans or pumps are required to move heated air or water, the heater is called an active solar heater. If the heated air or water from the collector moves to another part of the house naturally without fans or pumps, then the heater is called a passive solar heater .