Product Review Are Electric Radiant-Heated Floors Right for You Residential Building Products

Product Review Are Electric Radiant-Heated Floors Right for You Residential Building Products

Product Review: Are Electric Radiant-Heated Floors Right for You?

Nigel F. Maynard

The most common type of heating in U.S. homes is a forced-air system. It’s versatile — ideal for heating, cooling and fresh air — and perhaps the most affordable option for builders and home buyers.

But even though a forced-air system has many pluses, there are some drawbacks. They need to be sized properly and installed inside the conditioned airspace to be the most effective, they are prone to uneven temperature differences, they distribute allergens, some are noisy and most lead to dusty interiors.

One alternative to a forced-air system is a radiant-heated floor, which can be hydronic (liquid) or electric (dry). In a hydronic installation, heated water is pumped from a boiler through tubing laid in a pattern under the floor. It is “the most popular and cost-effective radiant heating systems for heating-dominated climates,” the Energy Department wrote on its website. An electric radiant, on the other hand, typically consists of electric cables built into the floor or mats with electrically conductive plastic mounted on the subfloor below a floor covering.

The beauty of the two types of radiant system is that they use a warm surface to transfer heat into a space rather than blow heated air through ductwork. Both types of systems provide comfortable, uniform heat, and are quiet and dust-free. “Radiant systems gently warm the air, leaving no hot air to rise and be wasted at ceilings,” wrote the Radiant Professionals Alliance in Mokena, Ill. “Objects are warmed, while cold windows and walls are neutralized by the heated surfaces.”

For those who do not want to invest in a full-blown hyrdronic installation, a dry system is the best option. In addition to being cheaper, a dry radiant floor does not require self-leveling compounds, concrete or mortar. The mats simply install under ceramic or stone tile, floating floors, engineered wood products and even carpeting.

But even though radiant heat is comfortable and enjoyable, it is not right for every application. Each type has drawbacks.

“While radiant-floor heat makes sense in certain buildings, it is not well-suited to highly insulated green homes for a number of reasons,” writes buildinggreen.com. “First, in a home with a tight envelope and a very small heating load, even a small amount of heat can cause overheating, and the thermal mass in a radiant floor system (especially with concrete-slab systems) increases the risk of overheating.”

Moreover, radiant only addresses heating, so homes in heat-and-cool climates will need a separate air conditioning system for hot days.

Electric systems may not be ideal for whole-house use. They are, however, ideal for zoned heating rather than a centralized setup. “Zone heating using a programmable thermostat means heating room by room, use by use — heat only where you want, when you want it,” said Nuheat in Delta, British Columbia.

Furthermore, DOE said electric systems are only cost-effective under certain conditions. “Because of the relatively high cost of electricity, electric radiant floors are usually only cost-effective if they include a significant thermal mass, such as a thick concrete floor, and your electric utility company offers time-of-use rates,” the department wrote on its website.

Time-of-use rates, the department explains, allow you to “charge” the concrete floor with heat during off-peak hours. “If the floor’s thermal mass is large enough, the heat stored in it will keep the house comfortable for eight to 10 hours without any further electrical input, particularly when daytime temperatures are significantly warmer than nighttime temperatures.”

In general, the cost of installing a hydronic system varies by location, size of the home and the type of installation, but whole-home installations tend to be pricey. A homeowner can expect to pay from $15,000 up to $30,000.

Electric systems are affordable. According to Nuheat, material costs for an electric radiant bathroom application range from $500 to $1,000, which includes the mat and thermostat.

If rooms in your home comply with modern insulation requirements for your region, the system can act as an effective and efficient heat source, Nuheat said. “This means less dependence on additional heat sources, as well as reduced energy costs associated with heating.”


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