As radiant heat continues to grow in popularity, contractors find themselves searching for the best possible application solutions to fit each individual customer need. Thor Vanderblue, a self-employed Connecticut contractor and the founder of his company, Thor’s Creations, found himself in this position when he began work on a 7,500-square-foot Heritage farmhouse in Fairfield, Conn. Armed with plastic tubing and multiple thermostats, Vanderblue started this project seeking to test an innovative radiant theory that combined hydronics and electric radiant heat floor mats.

FROM THE GROUND UP

“This farmhouse is classic architecture meets historic charm,” said Vanderblue. “With the increase in renovations in Heritage homes, I decided that an interesting concept would be to renovate a heritage farmhouse and show other builders the type of quality products that should be used in a home.”

With this in mind, Vanderblue chose to use Watts Radiant’s SubRay® subfloor radiant system. According to the company, the SubRay system is easy to install on top of existing frame or slab floors. It can be installed as a whole-house heating system or used to heat a basement or room addition. The system comes in 5/8- or 3/4-inch thickness, weighs less than two pounds per square foot, and removes the waiting time for a slab to cure, helping eliminate contractor scheduling difficulties. It consists of header sticks that hold radiant pipe at each end of the room on eight inch centers; sleepers that are six inches wide and two inches apart and support the finish floor; grippers that are used to hold the tubing where it enters or exits the floor; radiant tape that reflects radiant energy to the floor; aluminum conduction rolls that evenly spread the heat; corner sweeps that help the radiant tubing make 90 degree turns; and C-covers that protect the radiant tubing from nails and/or support the backer board.

“I ran hot water under a wide plank oak flooring using 1/2-inch E-PexB tubing,” noted Vanderblue. “A stainless steel, high-efficiency gas boiler from Munchkin produced more than enough hot water for the radiant system.”

The farmhouse has 10 zones for heating, seven of them hydronic. Vanderblue specified hydronic heating as the primary system citing lower energy costs, more even heat, better overall heating, and “frankly, I wouldn’t build a house without it.”

“Your feet and your body are warm,” he said. “It is easy to heat garages and basements with hydronics, and it can be used to melt snow on walkways and driveways. It was especially ideal for large areas, like the first floor of the farmhouse.”

COMFORT AND SAFETY

The farmhouse not only has large open spaces that the hydronic heating system provides heat for, but it also has a second floor, eight bathrooms, and a laundry room that need to be heated. Three of the bathrooms are heated with the primary hydronic heat system. Five of the bathrooms, however, are heated using Nuheat electric floor mats. This secondary heating system consists of multiple floor mats installed in custom and standard sizes. The laundry room also uses an electric heat mat. Each room with the secondary system is controlled by Nuheat’s Harmony seven-day programmable thermostat.

Underwriter’s Laboratory (UL) listed and Canadian Standards Association (CSA) certified, the Nuheat electric floor warming mat is pre-built like an electric blanket. Thin heating wires are embedded and for further protection encased in a stainless steel braid. The mats are then installed between two layers of thinset and controlled by a thermostat. All Nuheat thermostats are equipped with a built-in Class A ground fault circuit interrupter (GFCI) as required by electrical code. This safety device terminates the electrical power to the system immediately in the event of damage or a severe flood. The system doesn’t require installers to string out wire back and forth along the floor, which helps reduce labor cost, and it can be installed under tile, stone, laminate, and engineered wood. According to the company, it is perfect for zone heating and the repair of the system is simple enough that it does not require having to tear up all the flooring.

“Nuheat electric heat mats were the most cost effective way to heat the second floor bathrooms and the laundry room,” said Vanderblue. “In these locations, it was also easier to install than the hydronic heat making it a perfect fit for redoing the bathrooms.”

EFFICIENCY CONSIDERATIONS

When choosing a heating system, cost and efficiency are prime concerns both for the contractor and for the customer. Often, installation, maintenance, and usage prices are also taken into consideration when specifying home comfort systems. Although working on a high-end job, Vanderblue still had to calculate the cost and efficiency factors into the overall equation.

“I decided it would be a great benefit to use both hydronics and Nuheat as complementary systems in the home in order to maximize comfort,” he said. “Although the electric radiant is probably cheaper to install, it cannot be the only heat source. Hydronic radiant does have a higher up front installation cost, but over the long term, it is primarily cheaper to run.”

There aren’t any energy rebates for this “hybrid” heating solution yet, but with multiple zones, programmable thermostats, and minimal heating levels, it helps promote energy efficiency.

“I think that this hybrid system is the best of both worlds,” said Vanderblue. “Each system has its own advantages over the other, and as far as I am concerned there is no downside when it comes to this system.”

For more information, visit www.nuheat.com or www.wattsradiant.com.

Publication date: 10/08/2007