Control device for a in the mixed operation with solar energy and electrical current operated boiler

摘要

An appts. for controlling a water heater which uses solar and electrical energy incorporates automatic control of the electrical supply which cuts it off when the solar heating is in operation. The water heater comprises a vessel which contains a heat exchanger and an electric resistance. The heat exchanger is in its lower part and is connected to a solar energy collector. The electric resistance is in its upper part. Heat can be supplied by solar energy during the daytime when the sun is strong enough; by a central source in bad weather, by an economical combination of solar and electrical energy with priority to solar energy; by electrical energy rapidly according to demand for a limited period; by electricity at night at low cost and by solar energy during the day.