Solar Space Heating with baseboards and Radiators

Baseboards and other radiators demand high volumes of hot water at temperatures of around 150º-160º F (65º-71ºC), and solar hot-water systems alone can’t provide them.

It would be necessary a too large collector array and also a too large storage system, especially in winter time (when that goal is more difficult to attain). To overcome these difficulties you must add a boiler to the system.

The use of a boiler

If you want to use solar energy with radiators (including baseboard ones), you must use also a gas boiler or an oil boiler, to rise the hot-water provided by the solar heating system to the required temperatures.

This system – where the solar system function is to pre-heat the water used in the boiler – can be interesting in terms of energy savings, but all depends on elements like the implemented design, the type of collectors or the efficiency of the boiler (it should be a condensing combi boiler, to get higher savings).

Disadvantages

Since the most efficient modern boilers are of combi type, you should also pay attention to compatibility problems of these boilers with solar heating, whenever you intend to use them (something you must, whenever buying a new boiler). Not all the combi boilers are compatible with solar. See, on this issue: Combi Boilers Compatibility with Solar.

This three-fold solution approach – involving a solar hot-water system, radiators and a boiler – may provide some energy savings, but there are solutions with a wider scope and probably with a much higher efficiency.