What is Underfloor Heating

The floor structure is gently warmed producing a large radiant plane typically at 23 to 26 degrees C. The energy emitted is absorbed by people and objects without directly heating the air, resulting in a near perfect temperature profile between floor and ceiling.

It has long been accepted that for perfect comfort levels the human body should receive most of its warmth by radiant means, so warming the floor means that people experience warm feet and a cool head. The resultant comfort level is achieved at a lower air temperature than that produced by a convection system, and incurs no loss of air quality.


Some obvious advantages are gained by following this principle:

  • If the air is not directly heated and is at a lower temperature, then less heat is lost through the building fabric.


  • No direct heating of the air means that the humidity level is not degraded; buildings with floor warming systems feel much fresher.


  • High ceilings are of little consequence to floor warming systems as the comfort zone only needs to be where the occupants are, at   floor level.

Perhaps the most interesting point about floor warming systems is that they go completely unnoticed! Nobody feels too hot or cold, there is nothing to see and no obvious source of heat is apparent. This advantage extends into public buildings. The system is completely protected thus vandal proof.

How is underfloor heating implemented

There are 2 main methods:


  • Running special electric matting under floor coverings. Electric current is passed through the matting causing it to heat up and warm the room. This is cheap to install, but expensive to run. Many people with this system in their house do not use it because of the very high running costs.


  • Special piping is laid in the floor when the concrete slab is poured. Warm water is passed through the piping and gradually, gently heats up your floor. The temperature is generally controlled by a thermostat in the living area. When the room is cold, a pump is turned on by the thermostat and sends warm water though the piping. As the room temperature warms up the pump stops, so controlling the temperature. This is more expensive to install, but cheaper to run. Solar, oil, gas and wet back, combi systems all use this second method due to the vast difference in running costs.

To ensure this wonderful method of heating your house is economical and worthwhile, choose a building design that is energy efficient.

  • Reduce heat loss by insulating walls, floors and ceilings


  • Double glaze all windows, especially in cooler areas


  • Avoid down lights that vent heat into the ceiling cavity


  • Consider what passive solar heat is expected from the sunlight coming through the windows and striking building materials of high   thermal mass

Decide on the primary under floor heating energy source, and if possible combine it with a solar system.