Multiple circuit domestic heating system - has combined electric and solar energy heated hot water system

摘要

The multiple circuit heating system is used for room heating and for domestic water heating. The heating system has a separate electric water heater and a solar heating circuit. The water heater has a double wall, the inner wall of which forms the storage tank. The external wall encloses the tank and the space under the tank bottom. The space holds water and heating elements connected to the solar heating system. The water holding tank and space below the tank can be connected by a three way valve controlled by the hot water demand and the difference between the temp. of water in the space below the tank and that in the hot water return to the tank.