1 World Solar

Combined Solar Hot Water & Space Heating

A system combining solar water and space heating is designed to be larger than a standard domestic solar water heating system, to ensure provision of the extra energy demand of the space heating.

Solar energy can be used to meet some space heating demand in the spring & autumn, as shown in the graph. There is no demand for spaceheating in the summer, so the extra energy generated by the combined system is supplied to the hot water system.
Most suitable for connection to low temperature heating systems, such as underfloor heating.The payback of the combined solar & space heating system is not as good as a standard hot water system, as some collected solar energy cannot be used due to over capacity in the summer

Solar performance
On average a combined solar water & space
heating will meet 60-80% of the annual hot
water demand and around 10% of heating
demand in a new house. These figures are highly
dependent on the energy losses of the property
and the heat emitting system being used.

Design Rules of Thumb
Minimum collector area: at least 4 times
the size as needed for hot water only.
Typical area: 10-15m2