We currently have another underfloor heating project in progress in Orpington.
1) Depth of screed above the underfloor heating affects the heat transfer time through the floor, therefore using the correct depth of insulation below the pipe runs is crucial
2) The distance between the pipe loops has a bearing on the overall heat output of the floor. Closer together means more pipe and ultimately more output. Doing a heat loss calculation of the room will determine how much heat output you need…we will do this for you
3) The flow temperature running through the pipe also has a considerable effect on overall heat output. If you are planning to heat the floor with an ASHP these run more efficiently at cooler temperatures. Closer together loops will be preferable to ensure the room reaches temperature in the depths of winter
4) Underfloor heating thermal conductivity is affected by the finished floor surface. Stone and tiled floors are favourable for UFH, they soak up the heat and stay warm for very long periods of time. Carpet is a very bad conductor of heat, wood is somewhere in the middle. My advice to customers is to work backwards from the finished floor surface and discuss whether their chosen finished floor is actually suitable rather than leaving this as an afterthought.
5) We talk to customers about how they want to control their underfloor heating and how the zones are split up. VERY IMPORTANT. We use a lot of smart systems as they can also control the radiators within the same AP. You cannot just connect your UFH into your radiator circuit as we have seen lots of builders do on many occasions.
So there we go, 5 considerations to think about