Ask almost anyone in the heating trade about radiant panel heating and they’ll probably start describing tubing embedded in floors. Radiant floor heating is by far the biggest part of the radiant panel market. It’s an excellent approach in many projects ranging from residential all the way up to heavy industrial applications. However, it’s not necessarily the ideal solution in the coming generation of low-energy-use houses.

When viewed only from the standpoint of heat source performance, the low operating temperature of a bare concrete slab with closely spaced tubing (6-in. to 9-in. spacing) is very beneficial. A well-insulated house on a design day may only require supply water temperatures in the range of 85° F to 90° to maintain the interior space at 70°. Condensing boilers, solar collectors and hydronic heat pumps all love to operate at these low temperatures and show their gratitude by operating near the upper end of their performance range.