Radiant heat most commonly refers to a system of providing heat in the floor of a commercial or residential structure. Our building utilizes only a radiant system to serve our heating requirements. Radiant heating is known for its super efficiency, simplicity, comfort and quiet operation. Typically, radiant heat utilizes a special kind of plastic tubing (cross-linked polyethelyne or PEX), which is embedded in a concrete floor to allow for circulation of warm water. PEX tubing allows for substantial expansion and contraction in concrete without failing. By using a tiny (1/12 horsepower) circulation pump, instead of a loud 2-4 horsepower blower (as in, forced hot air) not only is heat put where we need it, but it is extremely quiet, does not effect humidity, and distributes heat efficiently, using very little electricity. Radiant heat combines well with another eco-construction technique that utilizes thermal mass.