How much tubing does a hydronic radiant system need to function effectively?
Installing the radiant tubing in the concrete slab is the most important step in the radiant floor heating process because it is difficult to fix a bad install once the concrete is in place. There are various tubing sizes used to create warm radiant floors. Slab size, tube spacing, heating demands, and under floor insulation are all factors that are taken into account to create a warm slab.
When a hydronic heating engineer calculates the heat load of the building, they will specify the size of tubing and length of loops from the header of the floor heating system. Larger hydronic tubing carries more heat and with potentially less resistance. By undersizing tubes or making loops too long, there is a greater possibility of cold spots in the hydronically heated floor. The tubes will release the heat in the area closest to the header and the loop coming back will be cooler. Not only will the building be cooler in certain areas but the boiler or floor heating system will not operate as efficiently as it needs to reheat the liquid from a lower temperature. It is crucial the installer of the hydronic floor heating system follows the manufacturer’s install specifications.