Solar Thermosiphon - Using Gravity In Your Solar Water Heating System

Using solar power in your homes can take two forms. You can use light rays or thermal rays to create energy. This article will concentrate on using thermal rays to produce hot water. It will focus on how the solar thermosiphon is used as a component of a solar hot water system. It will discuss the advantages of the thermosiphon over a traditional water pump.

Briefly, a solar water system is a solar collector that is heated up by the sun. The collector is designed to get the maximum effect from the thermal rays of the sun. It may be made of a metal or material that absorbs heat. It is usually painted matt black to increase this absorption of thermal rays. It will also have insulation so that once the collector is heated the heat does not dissipate to the environment easily.

The heat that is collected is then used to directly or indirectly heat water that can be used in the home. It is done directly by  literally pushing the water past the hot plate or through the piping. It is done indirectly by pushing some heat exchanging fluid past the hot plate. This fluid absorbs the heat and is then used to heat water.

A key component of such a solar water heating system is the water pump that is needed to push the water or fluid from the solar plate and into the home plumbing system.

A pump is a sub system of the solar hot water system. It is a system that has moving parts that require energy to power the moving parts. The moving parts impart this energy into the water and push it in a direction. Thus water pumps use energy to run and are liable to break down from time to time.

A thermosiphon has no moving parts and using heat and gravity to move water about. Thus it is silent, won't break down and costs nothing to run.

So how does a solar thermosiphon work ? It works on the principle that hot water rises.

For a thermosiphoning system to work the solar collector has to be located below the main water tank. It has to pipes that connect the collector to the water tank, one at the top of the tank and one at the bottom. As the water passes the collector it is heated. This causes the water to be less dense than before and it enters the water tank. The water at the bottom of the water tank is colder and through gravity is pushed to the solar collectors.

Thus by heating and gravity the water moves to and from the solar collector and into the water tank. A solar thermosiphoning system is less complex than a water pump but it also has to be laid out differently. This may rule on some locations and depending on where your home is located a thermosiphoning system may not be an option.