Radiant heating systems warm a home by supplying heat directly to the floor or to panels located in the walls or ceiling of a house.  Radiant heat systems work by transferring heat from a hot surface to objects in the room, including people, by means of heat radiation, also known as infrared radiation.  You experience radiant heating every time you cook on a stovetop or oven and the heat of the stove or over warms the kitchen.  However, despite the name, radiant heating, these systemsdepend heavily on convection, which is the natural circulation of heat within a room created by heat rising from the floor.


There are three main types of radiant floor heat: radiant air floors, which uses hot air as the heat-carrying medium; electric radiant floors, which and hydronic or hot water radiant floors.  The first is air-heated radiant floor systems, which are the least popular type of radiant heating and are seldom installed.  This is because air cannot and does not hold large amounts of heat, making the systems inefficient for residential or commercial use.  It was because of this that other forms of heating mediums were devised.

The second type of radiant heating is electric radiant floor systems, which usually consist of electric cables that are built into or under the floor.  Most systems feature electrically conductive plastic mats, which are mounted to the subfloor and under the either hardwood, tile, carpet, or other floor covering.

Electric radiant heating systems are more cost-effective if they include a thick concrete slab for their thermal mass.  When the thermal mass is large enough, it is possible to keep a home comfortable for up to eight to ten hours, which enables the homeowner to save considerable on their energy bills.

Electric radiant floors are also practical for additions onto homes, in that they are easier to install than having to run extra ductwork.  However, before making any final decisions, you should examine other options including ones, which also provide cooling options.

Hydronic systems are the third type of radiant floor heating systems and also the most popular as well as the most cost-effective system.  Hydronic radiant systems, heat by pumping hot water from a boiler through tubing installed on top of the subfloor and underneath the floor covering.  Some systems can even regulate the flow of hot water through each tubing loop thus regulating the temperature in each room.  This is accomplished by a system of zoning valves or pumps and thermostats.  How much it will cost to install a hydronic radiant heating system will depend on the size of the home, as well as the location.  Other factors include the price of labor, type of installation, and the type of floor covering.

Electric and hydronic radiant heating systems are installed in floors similarly.  Radiant heating systems can be installed in a concrete slab floor or covered with a lightweight concrete over a wooden subfloor.  This type of installation is known as wet installations whereas radiant heating systems, which are sandwiched between two layers of plywood or that’s tubing is attached under the finished floor or subfloor is referred to as dry installations.

Thick concrete slab systems provide a higher heat capacity for radiant flooring, however, thick concrete slabs have a slow thermal response time, and this makes planning temperature setbacks nearly impossible.  For this reason, it is strongly recommended to set a constant temperature.

With dry floor installation the systems cables/ tubing are run through an air space beneath the floor.  Dry floors are increasing in popularity because they are faster and less expensive to install.  However, they do have a draw back in that they require heating an air space.  This means that the system must operate at an increased temperature.

The installation of some dry floors involves suspending the tubing/ cables beneath the subfloor between the joists.  This method often requires that the floor joist be drilled through in order for the tubing/cables to be installed.  Reflective insulation must also be installed below the tubes/ cables to direct the heat upward. 

However, cables/ tubing can be installed also by sandwiching them between two layers of subfloor.  When using this method of installation, the tubing is then fitted into aluminum diffusers, which disperses the heat more evenly over the floor.  The cable/tubing and diffusers are held between furring strips, which support the weight of both the subfloor and finished floor covering.

Almost any type of floor covering can be used with radiant heating systems.  However, ceramic tiles are the most common as well as the most effective floor covering for radiant heating.  This is because of how well it conducts heat from the floor.  Other common floor coverings include vinyl/ linoleum, carpeting, and wood.  It is important to understand that floor coverings, which act as an insulator, such as carpeting, will decrease the efficiency of the system.

If you are planning to install carpeting, then consider using a thin carpet and padding.  This is because the temperature settings have to be higher under the carpeted areas in order to compensate for the carpeting.  If you are installing wood flooring, laminated wood flooring is better to use over radiant heating instead of solid wood because laminated flooring does not shrink and expand due to the heat. 

There is a lot to consider when installing radiant heating, however, nothing feels as nice and cozy as walking across warm floors in the winter.