Underfloor heating is well suited for use under carpet, provided that care is taken when choosing the carpet. The overall thickness of any materials above the heater need to be taken into account too as this will ensure efficient heat transfer. This includes any underlays and overlays.
LOW THERMAL RESISTANCE UNDERLAY & HESSIAN BACKED CARPET
The underlay should have low thermal resistance and the carpet should be hessian backed to promote efficient operation of the system. A felt underlay should not be used as it may create a thermal blocker hindering the performance of the system.
The floor temperature should never exceed 27 °C and a thermostat is used to ensure that this temperature is not exceeded. This means that the floor heating system is restricted to a certain maximum heat output. If you need help determining the heating requirement of your room and deciding on the suitable underfloor heating system, our expert team is available to help and can give you an estimate for heat loss and the heat output of the system and help you to choose the right product.
LIMIT VALUES FOR EFFECTIVE HEAT TRANSFER
When using underfloor heating under carpet, care should be taken to ensure effective performance of the system. Everything above the heater, including underlay, overlay and final floor finish need to be in the limits set below. The typical carpet is 1.0 to 2 tog, but you should always check with the manufacturer the suitability for underfloor heating and ensure that the overall tog value (including any underlays or overlays) does not exceed the 2.5.
It is not recommended to install underfloor heating with carpet if the limits below are not met. This may hinder the performance of the system and result in the system not working as desired.
|Tog||No more than 2.5|
|RSI||No more than 0.25|
|R-Value (US)||No more than 1.42|
|U-Value||No less than 4.0|
INSULATION IMPROVES EFFICIENCY
In order to achieve an efficient system, the subfloor should be insulated. This means that the concrete or plywood base on which the heating system is installed on should have additional insulation. Warmup insulation boards or Warmup insulated underlay are designed to give the best performance for the floor heater to provide heat through the underlay and the carpet on top.