With an underfloor heating system, the floor itself becomes the heat emitter and the heating of the room is from the floor up, unlike radiators in a normal central heating system where the emitters are mounted on the wall and the room is, effectively, heated from the ceiling downwards. Both electric and water based underfloor heating systems are available, they are almost identical apart from obviously, that one uses electric heating cable while the other circulated heated water through a pipe.
Water based UFH uses water heated to a lower temperature than conventional water central heating (typically 50°C rather than 60°C plus), which makes it ideal for use with a high efficiency condensing boilers; the lower operating temperature also makes it more suitable for use with heat pumps or solar water heaters.
The water temperature to the heating pipe is controlled by mixing the water in the pipe with hot water from the boiler to achieve the required temperature, this is then passed to a manifold for distribution to the various zones. Normally an existing conventional boiler will suit UFH, however it may be necessary to fit a higher rated pump as the back pressure may be greater than in a conventional radiator type central heating system.
Whichever system is used, the heat source is located under the floor and the area to be heated is separated into separate zones (normally one zone per room) and each zone is heated and controlled independently.
The 'benefits' of underfloor heating
- Water based UFH is cheaper to run than central heating using radiators, as the water used is at a lower temperature (typically 50°C rather than 60°C plus).
- The same level of comfort is achieved with the temperature in an UFH heated room about 2°C lower than in a room heated with conventional radiators. Wall mounted radiators act as convectors to heat the air, with underfloor heating, the whole floor area acts as a emitter for radiated heat.
- Unlike conventional radiators or heaters there are no hazardous wall projections or hot surfaces
- With no need for wall mounted emitters, there is less restriction on placing furniture in the room also less 'dust traps' so the rooms are easier to keep dust free.
- In wet areas, (bath, shower rooms, kitchen etc) the floors will dry off quicker.
The 'drawbacks' of underfloor heating
- One of the biggest drawbacks is the relatively slow response time of underfloor heating, especially where the pipe/cable is embedded in a solid floor. A wooden floor can take 30 minutes to an hour to warm up while concrete can take several hours - however the cooling time is also similarly long. This may not be considered a drawback if the property is occupied continuously or if the UFH is just used as 'background' heating.
- Underfloor heating should not be fitted under floor mounted units, which is quite easy to arrange in a kitchen where the position of base units etc are fixed.
A retrofit underfloor heating system specifically designed for retrofit, whole-house projects, extensions, conservatories and properties with lower levels of insulation