- A rooftop collector is made of absorbing surfaces with a glass surface on it.
- It absorbs heat from the sun and heats up the air in the space between the absorber and the glass.
- A well-insulated collector reduces heat loss.
- Hot air forces itself into the living space through vents and warms it. Cooler air takes its place and the cycle is repeated.
- Heat generated can also be stored for later use.
Source of all above images: Handbook on Energy Conscious Buildings