The sun radiation reaches the collector which heats the water inside it.
Heated, this water has its density decreased, turning into being “lighter”. Thus, the colder water pushes the hot water into the reservoir. As it is a continuous process, the flow of water between the reservoir and the collectors takes place, having as a consequence the so called natural circulation or thermal siphon effect, naming the system.
The hydraulic pump isn’t necessary in this kind of system.
2. PUMPED OR FORCED CIRCULATION
In these installations, the water circulation happens through a hydraulic motor pump activated by an electronic controller. The controller has the only function the activation of the pump when there is enough heated water in the collector, avoiding its unnecessary turning on. Despite including other items in the aspect of maintenance, pumped systems allow more freedom in the medium and big-sized installation.
In both systems, there are interconnecting tubes, an auxiliary system of energy and a tank of cold water that has the function of supplying the system, making the consumption of hot with immediate replacement of cold water possible. It is important to observe the height of the water level in this tank in relation to the thermal reservoir, since it will determine the work pressure of the thermal reservoir, an indispensable data for the acquisition and installation of a sun heating system. The auxiliary systems have the role of supplying energy in periods of low sun radiation or excess of consume. They are usually electric, by gas or through under-water resistance placed in the thermal reservoir.
It makes possible the installation of the thermal reservoir in the same level of the water tank. The system works in thermal siphon and the hydraulic pump isn’t necessary. Only the adaptation of the level kit in the standard thermal reservoir is necessary.
