What Is Radiant?
The warmth and comfort we feel from the sun on a cool spring day or in front of a crackling fire on a cold winter's night is radiant heat. Radiant floor heating uses a very subtle form of this same radiant energy. Radiant heat gently and evenly warms the surfaces of objects in the room. The air in the room is warmed when it comes into contact with the warmed objects, the largest of which is the floor. Heat loss is reduced and the radiant heat remains in the lower part of the room warmer near feet level and slightly less so at head level creating the perfect climate for comfort. Most of us are used to homes being heated by air, either forced air, which is blown from a duct by a fan, or air that is heated by a baseboard heater or wall radiator, which is then distributed by convection. The beauty of a radiant system is because the entire floor surface is so large, the temperature can be quite a bit lower than that of baseboard or wall radiators. Radiant Panel Association guidelines require that radiant floors should not exceed 85° in high traffic areas. To give you a feel for how moderate that temperature is, touch your own forearm. Human skin temperature is usually between 85° and 90°.
Floor Warming vs. Floor Heating
Floor warming is sometimes used in small areas such as bathrooms for the sole purpose of warming your feet when you get out of the shower. This is usually done electrically by embedding resistive wires or mats in the setting materials under the tile. This method is rarely the primary heat source of a home. Floor heating refers to radiant systems that are installed throughout most or all of the floor area of the home. Almost any modern well-built home, regardless of climate, can be comfortably heated with a radiant floor heating system as its sole heat source. In fact, a Warmboard system is the primary heating system for several buildings at the U.S. Research Station in Antarctica.