The Solarsheat G is based on the fresh air Solarsheat system, except that it has a hardened glass glazing and boosts the temperature of the indoor air instead of heating up outdoor air. Just like the Solarsheat Master Collecter the Solarsheat G has an integrated solar electric panel that powers the built-in fan. This is one of the easiest solar air heating systems to install. Expect the unit to last 25 to 30 years +. One unit is recommended for 750 to 1000 square feet of home space.