Research tests underfloor heating with carpet

Tests carried out for Nu-Heat by BSRIA on the effect of carpet on the performance of underfloor heating have shown that much heavier carpets can be used than is generally recommended. Andrew Grimsley, technical director of the company, explains, ‘Most underfloor-heating companies in the UK recommended that the combined value of carpets and underlays should not exceed 1.5 togs, with togs being a measure of a textile’s thermal resistance. In most domestic applications, this is unrealistic, as most quality carpets have a tog value of around two, not withstanding the underlay’s value. ‘We have always maintained that Nu-Heat underfloor heating will work effectively with carpets, provided that the combined tog value of the carpet and underlay does not exceed 2.5 togs.’ The BSRIA tests used Axminster Regina International carpet with a tog value of 2.16. It was laid with a Gates Technics 6 underlay with a tog value of 0.66. The combined value was in excess of 2.5 togs. Andrew Grimsley says, ‘The tests allowed us to benchmark our products more accurately and confirmed the suitability of carpets as a floor covering when used with our underfloor heating systems. ‘There are plenty of carpets available that fit into the target tog value. We recommend the use of rubber crumb type underlays, with felt underlays best avoided.’

Related links:

• www.nu-heat.co.uk