More systems available than ever
Nov. 18/25 2013; Volume 27/number 15
By Louis Iannaco
The use of radiant floor heating systems has grown rapidly in recent years, thanks to the introduction of innovative products catering to many different needs
According to company executives, one reason for the popularity of electric systems—the most-purchased type of radiant heat for flooring—is that they can be particularly useful in remodeling projects due to its method of installation. Many can be installed in a very thin thermal mass or mortar layer on top of a subfloor with a minimal increase in floor height.
A growing number of dealers are beginning to sell electric radiant products with flooring, particularly to their tile customers, because many systems can be sold in customized quantities.
The variety of available electric heating systems continues to expand. Some are intended solely for floor warming, and only under specific flooring materials, while others are designed as primary heating systems. Certain products are designed only for use under tile, but many can support a range of floor coverings.
Electric systems are available in many configurations, both in low and high voltage, as regular cable or as thin cable in preformed mats or in mesh. There are also elements embedded in plastic film or as self-regulating mats and cables. Self-regulating products are constructed so as the temperature of the mat or cable increases, the resistance goes up, which limits the heating output to a fixed temperature. Most electric systems are controlled with dual sensing thermostats that include an air sensor and floor temperature sensor.
In addition to electric heating systems, there has been recent growth of hydronic radiant floor heating units, which have inspired many innovative ways of installing tubing.
With hydronic radiant floor heating, warm water is pumped through tubing, which transfers the heat through the flooring. This particular method is versatile and can use almost any fuel or heat source: natural gas, propane, electricity, oil, solar or geothermal heat pumps.
Underlayments are often installed at the same time as radiant floor heating systems. According to Scott Rosen-baum, manager, technical support and engineering for WarmlyYours, the general rule is if the flooring manufacturer requires any underlayment, it must have a very low R-value, which is a measure of resistance to heat flow through a given thickness of material. “Otherwise, it will act like a blanket, trap the heat and keep the heat from getting to the top of the flooring surface,” he explained.
This is especially true when it comes to hardwood flooring applications. “The flooring manufacturer will determine whether the flooring needs an underlayment or not,” Rosenbaum said. “The heating wire will be embedded in a cementitious bed that the wood will be installed in direct contact with.” If the system is installed over a slab, Rosenbaum suggests using CeraZorb, an acoustical cork underlayment manufactured by WarmlyYours, to isolate the heating wire from the slab.
When it comes to ceramic tile, no underlayment is needed if installed over a wood subfloor. “If installed over a slab, [the underlayment] will isolate the heating wire from the slab,” he said. “As with hardwood applications, the slab will act as a heat sink and mitigate the warming of the tile.”
With resilient flooring, the heating wire will be embedded in a cementitious bed with which the flooring product will be installed in direct contact. “We recommend covering the wire with 3⁄8-inch of self-leveling underlayment,” Rosenbaum said. “That will provide a nice, flat surface on which to lay the resilient floor covering.”
According to Scott Cook, president, Warm Your Floor, radiant floor heating can be placed directly on top of most moisture barriers, while cork and other underlayment products can be installed beneath heating elements. “Glue or thinset cork directly to the slab to provide a thermal break, which slows the initial transfer of heat into the slab so the tile floor heats faster. Many installers choose this insulation layer, but it isn’t required.”
For frame floor construction, special underlayment materials aren’t required beneath electric radiant floor heating. “An installer simply preps the floor as usual to accept the flooring of choice, providing a structurally sound, flat and clean surface,” Cook said. “Then install the floor heating system directly on your subfloor of plywood, backerboard, etc., and you’re ready for the next step.”
When installing over a floor heating system, most underlayments used for laminate or wood floors are compatible with electric floor heating systems. “Thin foams or padding products typically have a very low R-value so heat passes through them easily,” he explained. “Since our floor heating systems are always embedded in a layer of mortar, there is no danger of the wires overheating, causing off-gassing or melting an underlayment; the layer of mortar acts as a radiant panel to protect the heating elements and evenly distribute heat across the floor above.”
The following are some of the radiant floor heating systems currently available:
The company’s QuietWarmth Fiber electric radiant heat underlayment is suitable for use under ceramic and porcelain tile flooring. Manufactured from a minimum 77% recycled textile fibers and carrying SCS Indoor Advantage Gold certification, it is designed to be clean, quiet and hypoallergenic.
QuietWarmth Fiber radiant heat underlayment features insulating qualities that add an R-value of 0.50 to the floor assembly that will keep floors warmer in the winter and cooler in the summer. Its acoustic properties are designed to dampen ambient sound in the room in which it is installed and minimize impact and airborne sound from traveling to the room below.
In addition, MP Global has introduced its new QuietWarmth Film. “This is a gentle radiant heat system designed specifically for floating wood and laminate floors that installs easily over a subfloor or acoustic underlayment,” noted Duane Reimer, MP Global’s technical director. “The roll-out line voltage system features gradual, supplemental warmth from low wattage resistance heating of ultra-thin, flexible radiant heat film, using just 6 watts per square foot to accomplish the same outcome as wire products that expend 12 watts per square foot, conforming to warranty requirements of many floating floors.”
Lightweight, maintenance-free and sporting a zero carbon footprint, QuietWarmth Film is also perfect for floating tile systems, Boesch added.
Manufacturing pre-built floor heating mats for more than 25 years, NuHeat products operate via designer-inspired thermostats. The company’s heating system is 7-day programmable, allowing the homeowner to control when, where and how much to heat.
The pre-built nature of the Nuheat mat offers very little room for failure during the install process while ensuring evenly distributed heat that is free from circulated allergens and particulates, which is not the case with traditional forced air systems, noted Kevin McElroy, vice president of sales.
“Of course, a heated floor is considered a luxury item, but the system is now also considered an energy-efficient alternative,” he explained. “Typically installed in kitchen, bathroom and basement renovations, Nuheat is a valuable upgrade to a tile, stone, laminate or engineered hardwood application.”
Nuheat’s product portfolio includes standard, custom, shower and cable system mats, as well as the Solo fully programmable thermostat, which is a revolutionary dual-voltage “all-in-one” thermostat exclusive to nuheat, McElroy said. Multiple Solo thermostats can be networked together and controlled from one Solo thermostat.
The company’s TapeMat Kits are promoted as “a heated floor in just one box.” Each floor heating kit contains one or two mats 2-feet wide in varying lengths plus everything needed to install a warm floor system. Kits 80 square feet and less include a single mat, while those 90 square feet and larger include two mats. The kit also includes the SunStat Pro II programmable thermostat.
Warm Your Floor
Warm Your Floor is uniquely positioned in the radiant floor heating industry as a radiant specialist, Cook noted. “Unlike other distributors, Warm Your Floor specializes in radiant floor heating products. It’s all we do, which means we can dedicate all of our time and energy to helping our customers understand the options available to them and answer every technical question they may have.”
The company is unique in that it carries several brands of electric radiant floor heating products, allowing it to offer “the right products for every floor covering and every room,” he said. “We can choose the best products from the entire marketplace to provide our customers with a single-supplier solution.”
Warm Your Floor’s focus allows it to work with contractors and dealers, whether a customer is looking to heat a bathroom, kitchen, sunroom, outdoor patio or melt the snow on her driveway or walkway.
The company’s indoor products can be installed under not only ceramic tile, but also engineered hardwood flooring, laminate, linoleum, vinyl and all natural stone all types. It can also provide heat for carpeted floors.
WarmlyYours currently offers two lines of underfloor radiant heat products: TempZone for installation under tile, stone and hardwood surfaces, and Environ for use under carpet, laminate and floating wood surfaces.
The company also offers slab heating for concrete floors, ideal for basements, sunrooms or additions, as well as five system controls and thermostats.
In addition, WarmlyYours offers 24/7 installation and technical support and a “No Nonsense” warranty. “We will create a free SmartPlan design of the project to the customer’s specifications by the next day,” said Victoria Hale, marketing affiliation manager. Measure-ment, project planning and thermostat programming services are also available.