Solar: Thermal Solar Systems
Solar thermal systems use solar energy to produce heat for domestic hot water or radiant heat.
How Thermal Solar Works
Solar collectors are mounted to the roof to absorb the sun’s energy and convert it into heat. The heat generated is then transferred to a heat-transfer fluid. The heat-transfer fluid is then pumped into a heat exchanger located inside the water storage tank where it heats the water. After releasing the heat via the heat exchanger, the heat-transfer fluid flows back to the collectors to be reheated. The controller keeps the heat-transfer fluid circulating whenever there is heat available in the solar collectors. In the winter, a boiler serves as an alternating heat source. Solar thermal systems can be integrated into existing hot water and radiant heating systems.
The Collector
The collector, which is normally installed on the rooftop, is the key component of a solar thermal system. It consists of tubing that is used to absorb solar radiation and convert it into heat. To minimize thermal losses, this tubing is embedded in a heat-insluated container. A heat-transfer fluid (usually a mixture of water and ecologically-safe anti-freeze) flows inside the tubing and circulates between the collector and hot water tank.
The Solar Controller
Solar thermal systems are operated by a solar controller. Once the temperature at the collector rises several degrees above the temperature in the storage tank the solar controller switches on the circulation pump and the heat-transfer fluid transports the heat accumulated in the collector to the hot water tank.
Heat Exchangers - Internal & External
- Drinking water storage tanks - are used for heating drinking water and consist of steel tanks that are filled with drinking water and equipped with an internal or external heat exchanger.
- Combination storage tanks - are used for both drinking water and supplying heating systems. They have two internal tanks to keep the water separated, or completely separate systems for hot water and radiant heat.
Thermal Solar Systems can be added to existing hot water heaters less than 2 years old and existing radiant heat systems.
