In-floor electric heating
These systems offer benefits that go beyond warming cold feetBy James Dulley
Electric in-floor heating, which can be used under tile, carpeting and hardwood, pinpoints and improves comfort. Not only that, it can allow you to lower the thermostat and still feel cozy and warm.
A home loses less heat through the walls, ceiling and windows when the indoor temperature is lower. The amount of electricity used is typically several percentage points less for each degree the thermostat is set lower. With improved comfort from in-floor heating, you should be able to lower the thermostat setting considerably and not feel chilly.
Another energy-saving advantage of in-floor heating is that each room can have a thermostat, allowing you to set different temperatures in various rooms and heat them as needed.
Instead of heating the room air, a warm floor radiates heat upward to your body. When your feet are warm, your entire body feels warm. In-floor heating reduces the extent of heat stratification where the hot air from a forced-air system naturally collects upward, near the ceiling.
In-floor heating is most commonly used in a concrete or tile floor with high thermal mass, but some types are designed to be used under carpeting, hardwood or laminate flooring. It can actually provide better comfort under carpet and hardwood because their low thermal mass allows the system to respond faster to thermostat changes.
In a concrete slab or under a tile floor, electric heating cable is usually laid in a serpentine pattern. In one design by Nuheat, long cable guides are nailed along the outer edges of the floor. Selecting how many slots to skip between cables determines the total cable length and heat output. It also simplifies even spacing.
Once the cable is in place, it is covered with concrete or thinset for tiles.
For use with carpeting, thin mats or sheets with electric cable embedded in them are placed on the floor before the carpeting is laid. The manufacturer can calculate the amount your rooms need, and the cable is available in 120 or 240 voltages.
WarmlyYours has a unique design with thin electric heating cables embedded in a strong fiberglass mesh. This is particularly effective for use under hardwood flooring and laminate. First check with your hardwood flooring manufacturer about the maximum allowable temperature to avoid excessive drying of the wood. Consider installing a special programmable thermostat with a laminate and engineered wood setting to protect the materials.
Another design by Heatizon uses a low-voltage heating mesh. This mesh is only about one-eighth inch thick and is stapled directly to the subflooring. It is low-voltage and installation is relatively easy. WarmlyYours also offers a wafer-thin heating kit that is placed between the pad and the carpet.
With in-floor heating, you don’t have to cover your entire house (or even an entire room), so you can add to the system as your budget allows. People sometimes add small custom mats or sheets in a dressing area or workspace. At a home center store, a 10-foot by 30-inch heating mat costs about $200, and a matching programmable thermostat is about $140.