A radiant floor is a type of floor system that supplies heat directly from the floor to object in contact with it or in its line of site. They depend on radiant heat transfer, which is the delivery of heat directly from the hot surface to object in the room via the radiation of heat, also referred to as infra red radiation. Infra red radiations are energy waves which are given off by all warm objects and produce heat in all objects they strike. A good radiant floor design includes proper insulation of the space to be heated (to minimize energy loss) and an efficient heating system. The 3 most common types of radiant floors are radiant air floors, electric radiant floors, and hot water (hydronic) radiant floors.
Radiant air or forced air floors are those in which heated air is pumped through a network of pipes and then heat is transferred via infra red radiation. Two disadvantages of radiant air floors is that air cannot hold large amounts of heat compared to other sources like water and they are usually not cost-effective. As many of us have noticed, the price of energy has been slowly increasing and may continue to do so. Most radiant air floors require a system such as a heater that requires electricity or fuel in order to keep the air warm. If the price of electricity keeps increasing so will your bill.
Electric radiant floors are floors in which electric cable or mats are built into the flooring system. Energy in the form of heat is passed through conductivity to the cable and then it’s dissipated through infra red radiation to other objects. Again, one of the big disadvantages of electric radiant floors is the high cost of electricity. Such system would only be cost-effective if it were to be installed in an area with significant thermal mass. Material with significant thermal masses, such as a thick concrete slab, can store large amount of heat and stay warm for some time. The heat stored in the slab helps warm up the space.
The most cost effective, most common, and one of the more efficient systems are hot water or hydronic radiant floors. Hydronic radiant floors are floors in which a network of pipes is placed within a flooring system and hot water is pumped through the pipes to keep the space warm. They usually require little electricity and water can also be heated with a wide variety of energy sources including standard gas or oil boilers and solar water heaters, all which have high energy efficiency. The temperature in each room can be controlled by adjusting the flow of hot and cold water as you would do with your shower. Although hydronic systems cost more up front than standard forced air systems, they are usually more efficient and last up to several years longer.