Thermal Transmittance Testing
A U-Value is the measurement of heat transfer through a section of material, in our case a doorset. The U-Value is measured in W/m2K. This is the rate of heat flow (Watts) through a metre squared of a doorset, where there is a temperature difference of one degree from one side of the doorset to the other. The lower the U-Value the better. A low U-Value means the doorset is better at keeping the heat inside the building, helping to make the building more environmentally friendly and energy efficient.
Thermal testing is undertaken to comply with BS EN ISO 10077-1. This is undertaken through a UKAS accredited laboratory at Exova.
By conducting our testing through a UKAS accredited test house we can have confidence that the tests undertaken are compliant with internationally agreed standards.
BS EN ISO 10077-1 is the standard which “specifies methods for the calculation of the thermal transmittance of pedestrian doors”
To undertake the testing we provide a section view of our doorset. This encompasses the door leaf, the frames and the infill of the doorset. Exova’s thermal test engineers then simulate the temperature transfer from one side of the door to the other using computer software. From this test, they then issue a report showing our test values and data as evidence of our products thermal transmittance value.
To improve our thermal transmittance, we can change the infill. Each infill has its own U-value, with certain infills better than others for the purpose of lowering the rate of heat transfer. For example, a mineral wool infill will perform better than a dufaylite infill, due to its lower U-value. Other ways to improve the u-value would be to add insulation into the frame and add seals around the door perimeter.