SYSTEMS

· forced circulation · natural circulation · once trough · solar plants ·

This is the classical hook-up for solar plants; it allows the maximum efficiency possible in whichever climatic condition. Up to a surface of 90 m² is possible with a single sunnyday solar panels battery.

The solar plant is fed from the mains through a Vrp pressure reducer valve, set at 3 bars. The Sc and Ss sensors check the water temperature respectively at the Bs solar panels battery outlet and at the bottom of the Sr accumulation tank. If the collectors are hottest than the tank, the Td differential thermostat activates the Ps solar plant circulation pump.

The Vnr check valve prevent from parasitic flows when the panels are cold. The water flows trough the panels in parallel; possible air in the circuit is discharged trough the Sa air discharge valve.

As in whichever solar plant, it is better that the Sr accumulation tank have no thermal back-up why this last interferes with the solar plant operation reducing the efficiency of relevant amounts. Down-stream the Sr accumulation tank, the Mt thermostatic mixer increases the water temperature, when too low, mixing it with very hot water prepared in a Scb auxiliary heater.

At the end of the operative season, a protection against the frost must be provided; if the panels have been installed with a sufficient slope (almost 20°), it is possible to drain them, other wise they must be filled with a brine of water and sodium chloride that prevent the freezing down to -20°C. In areas in which the frost is rare, also a forced circulation of water in the panels, when the panels temperature drops down to +4°C, can be used.