A great deal has been written in recent years about the rebirth of hydronic radiant floor heating. There has been considerable controversy over what type of plastic tubing to use and how much energy is saved by a hydronic radiant floor (HRF) system. But nearly everyone agrees on at least some of its advantages. Radiant floor heating systems provide a very comfortable way to heat. The entire floor radiates heat, so occupants never feel far from the heat source. Moreover, floors wetted by foot or vehicle traffic dry quickly. And there are no floor registers, exposed pipes, or radiators to interfere with furniture placement and room layouts. For these reasons, homeowners and