Why were tubes put in the basement walls instead of in the slab?
A basement slab is a natural place to put tubing since it is relatively easy to install. We wanted to keep 7′ basement ceilings so we only had enough room for 1″ of XPS insulation under the slab. The water table was also rather high in this neighborhood so the ground below the slab will be damp. Accordingly, we were worried that there would be too much heat loss below the slab. So we put radiant tubes in the plaster walls in the basement. These heat just as well as they would in the slab but were more expensive to install since the walls could otherwise have just been done with sheet rock.
