This new slab floor and our goal of energy efficiency point towards even, warm floor, radiant heat instead of the existing baseboards.
Solar Heat Source
Since hydronic radiant heat requires a lower temperature than baseboards, it is capable of incorporating several different heat sources for heating the water. Solar, wood, and gas fired boilers can be used together or individually to heat the house. The heat sources can be used in sync with modern control panels.
Fireplace Boiler
A great deal of research was required for the design and layout of the radiant floor and the sizing of the pipe/pump/boiler for the system. Despite all the advice to hire a professional, it appears that boiler installation companies quote and install by “rule of thumb” vs. an engineered design. In our house, the standard would be the pipe in the floor at 12″ on center without extra pipe at the edges where heat loss is highest. The pex would not have an oxygen barrier, and the boiler output would be based on the square footage instead of heat loss calculations.
Generic pex install in slab, 12″ OC tied to 6″ x 6″ wire mesh.
Radiant heat installations from online resources recommend basing the system on heat loss calculations which require an analysis of the roof, wall and window composition in the square footage and the air exchange rating from the Energy Audit.
The time spent on the radiant design was probably equivalent to taking a building science course on radiant heat. I spent many days of full time work learning how to size and design a radiant heating system. And that is after I figured out how to obtain Manual J calculations.