Today's Radiant Heat

 By BETH ORENSTEIN - Reprinted from The Morning Call

The house that Jim Macdonald designed had 18 foot ceilings, including the first-floor master bedroom suite. When he showed his floor plan to experts, they told him the best way to heat such open space would be radiant floor heat.

Radiant floor heat is what it says. Heat radiates from the floor, warming objects in the room. Conventional systems warm the air.

Radiant heat is a good choice for a two-story Southern contemporary house like Macdonald built in North Whitehall Township because the heat spreads evenly and stays at lower levels. With forced-air or radiator systems, the warmest air stagnates at the ceiling.

The heat in a radiant system comes from panels encased between the floor joists or in a concrete slab. The panels also can be placed in walls and ceilings. The panels contain thin, flexible tubing through which electricity or warm water circulates. Most installations use warm water, says Jeffrey Young, owner of Climatec in Wilson, which specializes in radiant heating systems.

Radiant floor heat is nothing new. "You can view old Roman ruins that have radiant heating in them," says Larry Drake, executive director of the Radiant Panel Association a trade group of about 650 members based in Loveland, Colorado.

Radiant floor heating is extremely popular in Europe largely because "energy costs there are triple what they are here," Young says. In this country, it's less than 1 percent of the heating market.

However, radiant heating systems have become more popular lately in this country. "We've just seen a tremendous growth, and it is growing all over from the Northeast to the West," Drake says.

 A typical residential radiant heating installation requires about 2,000 lineal feet of tubing. Industry sales have gone from 29.8 million lineal feet of tubing in 1992 to more than 99 million in 1997. That represents growth of about 25 percent a year, Drake says, "and we expect that trend to continue."

One reason radiant heat has become popular is that it has been featured on "This Old House," a public television series on home restoration. "The show's plumbing and heating contractor, Richard Trethewey, is one of the biggest advocates of radiant floor heating," Young says.

Some people are installing radiant heat throughout their homes, others are installing it just in sunrooms, bathrooms or great rooms, especially those with cathedral ceilings that are hard to heat. Improvements in technology also have made the systems more popular. Radiant heating has "been around for years and years, but the science that we use now is relatively new," Young says.

Much of the original tubing was made of copper and steel, and those systems were prone to failure. But the plastic that is available today "will last longer than the houses," Young says.

The most common tubing is PEX (cross-linked polyethylene), and it's so reliable that some manufacturers offer a lifetime warranty, Drake says. Its life is projected to be more than a 100 years, and there is little chance of leaks, he says.

Several hundred homeowners, many in the upscale Vail, Colo., area have complained recently about serious problems with a radiant flooring heating system they bought from Heatway Radiant Floors & Snowmelting of Springfield, Mo. The Heatway system used Entran II rubber tubing made by Goodyear of Akron, Ohio. At least eight of the homeowners have filed suits against the manufacturer. Both Heatway and Goodyear say their products weren't at fault.

Drake says the problem with Heatway, which has received much media attention. is unfortunate because it's with "one particular product that is no longer being manufactured and hasn't been for years. It's not what is typically used in the radiant industry."

Young, who started Climatec in '91, says the plastic tubing he uses does not leak. "I've got about a quarter million feet out there and I've never had I problem with any of it," he says. He has never used rubber tubing.

The water that flows through the tubing is warmed by a heating system or boiler. The boiler is fueled by oil, gas, electricity or even solar panels. A series of controls pump the heated water through the tubing. As the water circulates through the tubing, it releases energy and then returns to the boiler system to be reheated.

The heat is transferred from the warmed objects when it contacts a cooler surface. Whenever there is a temperature difference between two surfaces, both will attempt to equalize.

Radiant heating systems are more expensive to install than conventional heating systems - often as much as 25 to 30 percent more than radiator, forced-air or related systems. For obvious reasons, radiant heating is easier to install in new construction vs. existing dwellings. However, homes can be retrofitted with radiant heating.  Youg says his business is about half new construction and half retrofits.

Despite radiant heating's upscale price, Macdonald, who has lived in his home for two years, is convinced he made the right choice.

"It's the best," he says. "There's no matching the comfort. It's a very, very nice feeling to step out of the shower onto warm tile."

Radiant floor heat is also far more energy efficient than conventional heating systems. The efficiency comes from being able to set the thermostat lower without feeling chilly. Industry studies have shown that radiant floor heating is 20 to 30 percent more efficient than forced hot air heating. However, Young says, he finds "that comfort is what sells the system. Fuel efficiency is just a side benefit."

 While a radiant heating system is more expensive to install, homeowners can recover the installation costs in energy savings in a few years, contractors say. Macdonald figures his system will pay for itself in about eight years.

Macdonald says he used so little oil during the terrible winter a couple years ago that his dealer called and asked where else he was buying his oil. 'They said they were wondering because they were making only half as many deliveries as they should be based on the size of our house," Macdonald says. The four-bedroom house is 4,800 square feet.

 Another reason that some home-owners are opting for radiant heat is that it doesn't stir up dust or allergens like forced-air systems do. "Its a very hygienic system because there is no air circulation, Young says.

Also, radiant systems cut on heat loss through infiltration. Forced-air heating pressurizes a dwelling, pushing warm air out through cracks and openings. A  house heated solely by radiant heat isn't under pressure, so room air stays inside.

Yet another advantage to radiant heat is that there are no grills or baseboards, so furniture can be placed anywhere in a room. "Because there is no duct work in the walls it makes for a very clean looking room," says Macdonald, who served as his own contractor.

 Because there are no blowers, radiant heating systems are extremely quiet, too. "One of the best things about radiant floor heat is you don't know it's on."

Radiant systems can be used for cooling as well, but generally don't work well in the Northeast's climate because of the humidity. "Around here you still need to have a standard air conditioner to remove the moisture," Young says.

Radiant heating panels can be installed in about six different ways, "but they all work," Young says.

Radiant heating can be used with any type of flooring: tile, hardwood or carpet. "Some people are scared of radiant under hardwood floors," Young says, "but it's nothing to be scared of. There are certain limitations you have to stay within. Things just have to be designed around those limitations.

Climatec Advanced Heating Technologies - P.O. Box 3910, Easton PA 18043

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