A common question we get asked when people install their underfloor heating is what what pipe centre should be used. This is also raised after quote submissions as often times people are confused why the pipe centres can differ throughout the house. But the answer is pretty straightforward- pipe centres vary to suit the heat requirements for that particular room based on varying factors.
The pipe centres in a wet underfloor heating system is determined by the type of floor covering, the type of room, height of ceiling and what type of heat source is being used. These are some of the most important factors to consider.
200mm centres is recommended in most underfloor heating systems that have hard floors, standard ceiling heights and using a boiler. The harder the floor covering the easier it is to transfer the heat from the pipes to the floor. So any type of tile and stone flooring are good heat conductors that once heated hold the heat well. Wood and laminate are good but being slightly less dense than stone or tile lose the heat a little faster.
If your underfloor heating system is heated by a ground or air source heat pump all centres need to default from 200 to at least 150mm. Heat pumps cannot generate as much heat as boilers can so to balance the loss in temperature the centres need to be much closer.
Carpets loose heat the quickest and are poor heat converters and because of this any room with a carpet needs to be using 150mm centres minimum if put into screed. If you’re putting in underfloor heating on joisted floors with carpets and using aluminium spreader plates, you’ll need to bring the pipes closer together to 120mm centres since spreader plates aren’t available at 150mm centres.
Points to remember:
- High heat loss rooms such as those with folding glass doors, conservatories and vaulted ceilings should use 150mm centres as standard
- An underfloor heating system using an ground or air source heat pump must default the standard centres from 200mm to 150mm as the flow temperature in the system runs slightly cooler than one fed by a boiler.
- 150mm centres should be used in any rooms with carpets unless the system is installed on joists, in which case use 120mm centres
- The tighter you bring the centres together the more heat you will produce