Solar heating (Space) means heating the space inside a building. Today, many homes use solar energy for space heating. A passive solar home is designed to let in as much sunlight as possible. It is like a big solar collector.

Sunlight passes through the windows and heats the walls and floor inside the house. The light can get in, but the heat is trapped inside. A passive solar home does not depend on mechanical equipment, such as pumps and blowers, to heat the house, whereas active solar homes do.

Solar Heating – Water

Solar energy can be used to heat water. Heating water for bathing, dish washing, and clothes washing is the second largest home energy cost. Installing a solar water heater can reduce your water heating bill by as much as 50 percent.

A solar water heater works a lot like solar space heating. In our hemisphere, a solar collector is mounted on the south side of a roof where it can capture sunlight. The sunlight heats water in a tank. The hot water is piped to faucets throughout a house, just as it would be with an ordinary water heater.

Passive vs Active Solar

Passive solar buildings also maximize the free inputs of solar energy as heat during cold seasons, and protect the building’s interior from too much sunshine in the warm seasons, while allowing enough daylight to reduce the need for electric lighting.

Letting the sun heat buildings in winter and letting daylight enter them to displace electric lighting is the least-cost form of solar energy. Passive cooling techniques are based on the use of heat and solar protection techniques, heat storage in thermal mass, and heat dissipation techniques.

The cost-effectiveness of active solar space heating systems does not only depend on solar resource, but also on the heat demand. In France, for example, space heating systems offer better economic performance in the east or the north while solar water heaters are more profitable in the south.

The most cost-effective applications are usually found in mountainous regions or countries, such as Austria and Switzerland, where reduced atmospheric absorption of solar energy drive up both the heating loads and the solar resource. Active solar space heating requires more complex installations based on solar collectors of various types and some storage.