The human body is most comfortable with a temperature of 75 degrees F at our feet and a temperature of 65 degrees F at our head. With this temperature curve our feet and bodies are warm while our head is slightly cooler. We feel warm, comfortable and alert.

Now, look at the Radiant Floor Heating Curve - . Radiant floor heating is the only heating system that gives you a room temperature curve that matches the Ideal Heating Curve for the human body. Warm at the floor and cooler at our head. Chart illustrates the room temperature curve you get with forced air heating. It is the exact opposite of what the human body requires. With forced air we can have cold feet, an uncomfortably cool body and we feel tired because the air is too hot in the top half of the room.

Disadvantages
Long heat up period

Requires major disruption on existing buildings

Long cooling down period

Cannot respond rapidly to quick temperature changes

Choice of floor finishing requires careful consideration

Changes of floor finish may affect performance

So-called "wet" installations embed the cables or tubing within a solid floor and are the oldest form of modern radiant floor systems. The tubing or cable can be embedded in a thick concrete foundation slab (commonly used in "slab" ranch houses that don't have basements) or in a thin layer of concrete, gypsum, or other material installed on top of a subfloor. If concrete is used and the new floor is not on solid earth, additional floor support may be necessary because of the added weight. You should consult a professional engineer to determine the floor's carrying capacity.

Thick concrete slab systems have high heat capacity and are ideal for storing heat from solar energy systems, which have a fluctuating heat output. The downside of the thick slabs is their slow thermal response time, which makes strategies such as night or daytime setbacks difficult if not impossible. Most experts recommend maintaining a constant temperature in homes with these heating systems.

Due to recent innovations in floor technology, so-called "dry" floors, in which the cables or tubing run in an air space beneath the floor, have been gaining in popularity, mainly because a dry floor is faster and less expensive to build. But because dry floors involve heating an air space, the radiant heating system needs to operate at a higher temperature.

Floor Coverings
Ceramic tile is the most common and effective floor covering for radiant floor heating, as it conducts heat well from the floor and adds thermal storage because of its high heat capacity. Common floor coverings like vinyl and linoleum sheet goods, carpeting, or wood can also be used, but any covering that helps to insulate the floor from the room will decrease the efficiency of the system.

If you want carpeting, use a thin carpet with dense padding and install as little carpeting as possible. If some rooms, but not all, will have a floor covering, then those rooms should have a separate tubing loop to make the system heat these spaces more efficiently. This is because the water flowing under the covered floor will need to be hotter to compensate for the floor covering. Wood flooring should be laminated wood flooring instead of solid wood. This reduces the possibility of the wood shrinking and cracking from the drying effects of the heat.