"Space heating" refers to the process of heating the air or the environment inside a building, such as a home or an office, to make it warm and comfortable. Full definition
The system uses solar to heat water, which is in turn used for space heating in a radiant floor system. (builditsolar.com)
This enables a result for specific space heat demand to be calculated quickly using default values, potentially saving significant time. (designph.org)
In my case, the system involves very little extra cost or work because nearly all the components are already there for the existing solar space heating system. (builditsolar.com)