There are two basic types of solar home heaters, the active system and the passive system. The active solar home heater uses heat collection units that are placed in a true south orientation at an angle of the latitude of you home plus 15 degrees. This maximizes the amount of solar heat that is collected. Many active solar heaters require a storage area where the heat from the collectors can be stored and disbursed at regular intervals.
These units require sophisticated mechanical and electronic components in order to work. The heat storage areas must be fairly large. Most often, the heat is stored in large stone blocks and disbursed by mechanical means as it is needed. Many homes with active solar home heaters are tightly sealed to prevent heat exchange. This can result in indoor air problems since ventilation is necessary to keep inside air fresh and oxygenated. It can also result in a build up of humidity in the home, which can lead to problems with mold and mildew.
Most existing homes cannot use active solar heat as the sole means of heating the home. Most banks will not finance homes with solar home heaters unless they also have back up heating systems. Active solar home heaters use air or a water glycol mixture to move the heat from the storage area or collectors into the home. The solar home heater doesn't create as much heat as conventional heating systems and requires more area to disburse the heat.
While active solar home heaters are not yet practical as the sole source of heat for the average home, they can be supplemented with electric or gas heating units and will still result in a significant saving of energy. Active solar home heaters can supply as much as 50% of the heat for the average home, depending on the home's location. In some areas , the savings may be significantly more.
Passive solar home heaters are built into the actual structure of the home. It isn't possible to use passive solar heat in a conventional home. The orientation of these homes must be true south and the materials used to build the homes must be able to absorb heat efficiently and disburse it slowly. In a passive solar home heater, the home itself is the heater. There are no mechanical or electrical systems.
The most practical method of utilizing the sun for heat in a conventional home is probably to use solar panels which convert sunlight to electricity. The electricity can then be used to power a standard electric heat pump. While the solar panels will probably not produce enough electricity to cover all the power needs of the home, they can produce between 50% and 70% of the necessary electricity. Heat pumps can also be used for airconditioning.
The technology for solar home heaters is improving. So is the technology for solar electric panels. As these methods become more efficient and less expensive, more homeowners will be able to take advantage of the savings of both money and energy offered by using solar power. As people use more perpetual energy sources the need for fossil fuels will diminish along with the production of greenhouse gases. Solar power can turn the tide of global warming.