Underfloor heating systems turn the whole floor into a heat emitter.They can be electric or water based. In an electric system, a cable is embedded in the floor and the resistance in the cable causes it to heat up. Water based systems circulate hot water from a boiler or other heat source. Because water based underfloor heatong systems circulate water at a lower temperature than a radiator based system, they are particualrly suited to using a heat pump (more) or a condensing boiler (more) as the heat source because typically heat pumps  and condensing boilers are more efficient at lower water temperatures.

Underfloor heating can be used with timber floors and solid concrete floors, but the system used must be suitable for the floor type. Insulation must be installed so that the heat is not wasted and rises into the room rather than going into the concrete sub-floor or in the case of a suspended timber floor, the ventilated space under underneath. Floors should not be carpeted as this will act as an insulator and prevent the heat being distributed.

Advantages of underfloor heating are that there is no need for radiators and heat is evenly distributed. A disadvantage is that warm up time is slow so they are best suited to situations where continuous heat is required (careful setting of timers can lessen this, by setting the 'on' and 'off'times in advance of the actual period for which heat is required). more