Floor heating pipe is a key component of radiant floor heating systems. Its primary function is to transfer water or a mixture of water and antifreeze into the closed loop that is recirculated through the flooring system. It also provides heat distribution for wet or dry hydronic underfloor heating systems. There are several types of pipes available for this type of application including PEX (cross-linked polyethylene), PEX-AL-PEX, and copper.
Choosing the correct size tubing is important to ensure that the desired level of heat can be achieved with the minimum amount of energy used. Tube sizing is determined by the desired room temperature, water pressure, slab thickness and tubing spacing. Tweaking any of these variables can significantly affect the heat output.
For residential thin slab applications 3/8″ oxygen barrier PEX is the most commonly used size. This size produces the least slab height increase and allows for quicker installation while still providing adequate heat output. The recommended loop length for this size is 300ft.
For thick slab or commercial applications, 3/4″ oxygen barrier PEX is typically used. This size is ideal for both wet or dry hydronic underfloor heating and provides sufficient heat output for most areas. In general the optimal tubing spacing is 12″ on center. This spacing allows for faster response, minimizes thermal expansion, and helps to produce an even distribution of radiant heat. floor heating pipe