Basic 4-1-1: A radiant heat flooring system can either be electric (wires) or hydronic (tubes of heated water) with evenly spaced heating elements. The water-based systems are about 5x more commonly installed than wire-based system. According to the Radiant Panel Association, about 150,000 to 160,000 homes were installed with hydronic-tube systems in 2005 compared with 31,000 electric installations.
Some systems have the heating elements embedded in a polyester mat while others use free running cables that must be wound into a mesh. Prior to 2005, the average annual growth rate was 19 percent for hydronic systems, which also include supporting equipment such as controls, pumps and heat sources. Meanwhile, growth in the electric radiant market is a moderate 7 percent.
One wire-based system, from Nuheat, is a mat method in which embedded wires that are 2 inches apart are sealed between two pieces of non-woven polyester fiber, creating an "electric blanket." It is laid on the subfloor and then the finish floor is placed over it and adhered to the mat using thinset.
The air in the room is warmed when it comes into contact with the warmed objects, the largest of which is the floor. Heat loss is reduced and the radiant heat remains in the lower part of the room, warmer near feet level and slightly less so at head level, creating the perfect climate for comfort.
Pluses 4-1-1: Radiant heat offers a quiet, efficient delivery method that is also considered cleaner than forced-air systems because it does not require air to pass through ducts. It also offers even distribution of heat throughout a room versus from specific locations, like a duct or radiator. Radiant heat is powered by the same methods used for more traditional heating systems, such as natural gas, propane, oil, wood, electricity or solar.
Because a radiant system heats the entire floor (or wall) surface, the temperature can be much lower than that of baseboard or wall radiators. According to guidelines from the Radiant Panel Association, radiant floors should not exceed 85 degrees in high-traffic areas. (Human skin temperature is usually between 85 degrees and 90 degrees.) Installation 4-1-1: Instal-lation time depends entirely on the person installing. People with no construction experience to the savvy weekend warrior homeowner, right up to the professional contractor, can install these systems. It can take as little as under 20 minutes, depending on the room and the skill of the installer. Anyone can install it: heating contractors, tile contractors, electricians, general contractors, architects, builders or homeowners. It is recommended that an electrician hook up the wiring.
Cost 4-1-1: Cost completely depends on the size of the room. A builder can do an average bathroom between $500 and $800, marking it up according to his own margin. Local distributors typically will mark up the systems anywhere from 15 to 25 points. In terms of usage costs, one manufacturer claims its system uses the same amount of energy as that of two light bulbs.
Marketing 4-1-1: Most of the manufacturers offer quality collateral brochures and counter displays, as well as online assistance. For example, Nuheat just launched a specification division entirely dedicated to architects, builders and developers. This service is geared toward high-end developing of multi-family units as well as spas, resorts and hotels. One way builders can market radiant heat flooring is through special events in their design centers or model homes, such as a "socks only" party for watching a football game.
Codes/Standards 4-1-1: The Radiant Panel Association offers standard installation guidelines and a certification program covering both electric and hydronic installation and design. The program covers fundamental knowledge as well as how to integrate the systems with conventional heating systems.
More 4-1-1: Additional information on the category can be found at www.radiantpanelassociation.org.