The thermal reservoir is like a special water tank that keeps the water stored in the solar heater warm. These cylinders are made of copper, stainless steel, or polypropylene and then receive thermal insulation. Most models of thermal reservoir come with an auxiliary electric heating system, but can be manufactured with an auxiliary gas system or even without this feature.
Models of thermal reservoirs range from 100 to 20 thousand liters. The size of the thermal reservoir, that is, the volume of water it is capable of storing, is calculated by the technicians after the user answers a series of questions. In the dimensioning of the solar heater, it is necessary to know how many people will use the system daily, the average duration and the number of daily baths, how many will be the hot water usage points, or the size of the pool, and so on.
