Carpet and Heated Floors
The advantages of energy efficiency combined with a distinctly comfortable heat source have made heated floors increasingly popular in many parts of the country. Often referred to as hydronic or “radiant heated” floors, these floor systems have been popular in Europe for many years. Most systems utilize low temperature water of about 80°F to 125°F flowing through flexible tubing installed beneath the floors. These systems can be embedded in concrete slabs, lightweight overpours or in joist cavities.
Floor Covering Considerations With installations involving carpet and cushion, consideration must be given to the thermal resistance rating (R-value) of the carpet and cushion products. Manufacturers of heated floor systems state that less thermally conductive floors, such as those covered with thick carpets, particularly with heavy cushions beneath, may require the use of hotter water. Regardless, most homeowners accept some efficiency reduction so that the additional benefits offered by carpet will be enjoyed. A not-so-obvious benefit not to be overlooked is that carpet tends to shorten the heating season by providing a “warm” floor rather than a “cold” floor as with other types of floor coverings. The efficiency of heated floor systems can be improved by properly selecting the carpet cushion. Most radiant heated floor manufacturers suggest a total maximum R-value for carpet and cushion installations not to exceed 4.0. With heated floors, lower pile carpet and lower thickness cushion are better than higher pile carpet and thicker cushions. When cushion is used, it should be no thicker than 3/8”.
Carpet Thermal Study An industry sponsored study on the thermal characteristics of carpet with and without cushion conducted by the Georgia Institute of Technology School of Textile Engineering concluded that the total R-value is more dependent on the total thickness of the carpet than the type fiber content. When the carpet R-value is not available, the study suggested to multiply the total carpet thickness measured in inches by a factor of 2.6 to approximate the carpet’s Rvalue. The study also found R-values to be additive for any combination of materials. For example, a combination of carpet with an R-value of 1.3 and a prime polyurethane cushion with an R-value of 1.6 will yield an overall R-value of 2.9.
Installation Considerations When the direct glue down method of carpet installation is used, the heat should be turned down to keep the adhesive from drying too quickly before receiving the carpet. When installing the tackless strip for stretch-in installations, the fastening nails should not be driven into the tubing or cables embedded in the floor. Most conventional carpet is suitable for use over heated floors; however, it is advisable to confirm with the carpet manufacturer that the backing is resistant to long periods of low continuous heat. Thanks again to J.J. Haines for the informnation. Please take a moment and look at stoversliquidation.com