There are several methods that solar energy can be used to heat buildings. By far the most common method, which just about every building benefits from, is by using windows. The appropriate use of windows along with building design is called passive solar heating.

 

Over a year, most window types loose more energy than they gain. Some advanced windows are actually net energy suppliers, offering better energy performance than a R30 wall. Advanced windows use a combination of double or triple glazings, low-emittance coatings, argon or krypton gases, and transparent insulation.

 

The Trombe wall is a building design concept that has been around since the 1970s. The Trombe wall has never gained wide acceptance, but its potential has improved thanks to advances in transparent insulation technologies. Liquid-based collectors can be used in a solar-assisted home heating system. Basically a collector area of 20 square meters or more is used along with a large thermal storage volume designed for a 1-3 days of heat storage.