Homeowners in warm climate states typically have their swimming pools outside. Folks in cold weather states have swimming pools in a building. We split this solar pool heating page into two main sections: Outdoor solar pool heating and indoor solar pool heating. The main difference between the two is that an outdoor system typically uses external tubing to circulate water between one or more solar collectors and the pool. Indoor pools can keep the water warm by designing the building for winter solar gain. Of course, if need be, both techniques can be used together.
Outdoor solar pool heating is one of the easiest projects that you can do. It involves two principals: circulation and exposure. You need to circulate water from a solar concentrator to the pool and back in a closed circuit. The concentrator material can be as simple as a garden hose painted black and exposed to full sun. Additional optional components are valves, filters, and sensors. Here are some examples of home made and professionally install solar pool heating systems.
This is a very basic system, in which, black solar collector tubing is wrapped around the pool fence. It has the advantages of simplicity, using existing infrastructure, and
This indirect technique operated like a car radiator by blowing hot air from the attic into a pool water circulating concentrator. It has the dual benefit of heating your pool water and cooling your house. As long as it is sunny outside the attic pool heater can raise your pool temperatures.
The system has two sensors that control a valve so that when the attic heater is not adequate it gets bypassed. The attic pool heater uses the regular pool water filter and pump the circulate the water. Hot air from the attic is moved by a regular fan. So the only additional power consuming component is the fan, which costs about $10 - $15 month to operate. That is much less than trying to heat the pool with natural gas.
The company claims it can add 6 weeks to the front and back ends of your swimming season. The company also claims that these systems have been installed and proven in 40 states of the USA, even some of the cold weather states.
This type of pool heating system uses two concentric tubes of extremely high tempered glass with a vacuum seal between. The vacuum prevents heat losses. The outer glass tube is clear allowing maximum solar penetration. The inner tube is covered with a black sputtering to absorb sun light. When sunlight strikes the collector, the solar radiation goes through the clear glass of the outer tube and is absorbed by the coating on the outside of the inner tube. This solar energy is then changed into heat energy by the coating surface and thus, heats the inner tube.
Rome dominated ancient Greece before Jesus walked the Earth as a man. Romans assimilated the best ideas and architectures of the cultures they conquered, including the Southern orientation of homes in well-planed Grecian solar communities. Romans are credited with the discovery of glass. It was probably a large fire that melted beach sand into translucent glass. Romans soon learned that glass on the south side of a building warmed the room in the Winter, but that glass on the west side created a “solar furnace” in the Summer. Romans also learned the relaxing pleasure of luxurious hot baths. By 300 A.D., there were 900 of them in Rome. Hot baths were built wherever the Romans moved in the ancient world. There is a town in England named Bath, built by the Romans near a geothermal hot spring.
This kind of design basically involves placing large panes of glass on the side of the building facing the equator. This allows the low winter sun to penetrate far into the structure and (re)fill the thermal mass of the building with heat. If the pool receives most of this sun light, the water can hold the heat for long periods of time.
The size of the large equator facing window is dependent on your latitude. The further north your pool room is located, the larger the window should be. Here is an architectural overview of passive solar pool room considerations. It is a holistic approach to passive solar home design.