Floor heating pipe is the conduit that carries hot water through your radiant system. There are a few different types of pipes that can be used, but PEX is the most popular choice as it’s easy to install and has many advantages over metal piping.
PEX is a flexible, durable plastic that can endure abuses and freezing that would compromise a metal pipe. It also doesn’t corrode or leach into the water like copper. Additionally, it’s less expensive and safer to use compared to traditional metal piping.
Heat is transferred through the pipes in two ways: conduction and radiation. Conductive transfer occurs when two objects of differing temperatures come in contact with each other — think about touching a steel pole. The warmer pole transfers its thermal energy to your hand, causing it to feel warm. In radiant systems, the PEX tubing transfers its energy to a slab or subfloor through this same process, but with much higher water temperatures since it is in direct contact with the cooler surface.
The amount of heat that is transferred depends on the size of the tubing, the spacing between tubes, and the water temperature. A typical residential application uses 5/8” barrier PEX with 12” on center spacing, and this produces around 30 BTU’s per square foot of the floor area. Larger spaces or poorly insulated areas require larger tubing diameters and closer spacing to reach desired temperatures. For this reason, it’s important to determine your space’s heat output requirement before deciding on the proper pipe size and spacing. floor heating pipe