Radiant floors are a home heating method that doesn’t use traditional HVAC air ducts. Instead of warm air blowing through vents, heat from a source beneath the floors warms the home from wall to wall. Here’s what you need to know about radiant floors.
Bottoms-up heating
With traditional heating, the warmed air is blown through ductwork installed above the ceilings or through basement crawl spaces. Heat enters the room through vents.
Radiant floor heating conducts warmth through the floor. Floors are heated from beneath either by electrical coils or heated water flowing through tubes. The heat from radiant floors distributes evenly from wall to wall in each room. No more putting your feet down on chilly tile or hardwood — with radiant flooring your toes stay toasty while heat rises evenly throughout the entire room.
Radiant floors cannot be cooled in summer, so a home with this form of heating will still need a separate air conditioning system that uses ducts.
Types of radiant floors
The electrical type of radiant heat uses resistant coils laid evenly beneath the home’s flooring. The most popular version is made with mats that fit together like puzzle pieces. It’s easiest to install this type of radiant heating when the home is being built. But if you can access the floor from a crawl space or basement, you can install the mats from underneath between floor joists without having to remove the finished floor. The mat method is best when retrofitting an existing floor. A thermostat, which can be controlled by a timer, controls the system.
The second type of radiant flooring is hydronic floor heating. This system pumps hot water through PEX tubes laid in even coils beneath the floor. The tubes are either embedded in mortar or fitted into grooved channels of plywood subflooring. (The plywood type can only be used when the finish flooring is tile.) This system can also be placed between floor joists from beneath. Hydronic heating systems have a dedicated water heater separate from the one the home uses for bathing, cooking, laundry and the like.
Radiant floor heating is more expensive to install than a traditional system, but operating costs will be lower because there are no ducts to leak.
Installing an electric system using mats is a project that many do-it-yourselfers can handle. This type of radiant floors will cost between $5 and $7 per square foot to install yourself. Double that cost if you hire out the job. Hydronic systems are more difficult and should be left to a professional installer.
Things to consider
Installing radiant floors is easiest in new construction. Retrofitting existing floors requires either pulling up current flooring or accessing the home’s floors from beneath through a basement or crawl space.
Both types work best with hard floors rather than carpet, which inhibits the heat from rising to warm the room. Tile floors work the best with radiant heat because the material conducts well and can withstand high temperatures. Heat can cause wood floors to expand and contract, potentially creating gaps. High temperatures can also affect vinyl and plastic laminate floors. Consult a flooring professional if your floors are not built from tile.
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