Floor Heating Output Explained

Underfloor heating output can be referenced in two ways.

The first relates to the value of watts per square metre of a heater, as in the power output per unit area of the heater. The other value also refers to watts per square metre, but this time in relation to the area of the room itself. It is this second value that we look at to determine whether there is sufficient wattage to heat the entire room, as opposed to only warming the floor underfoot.

For example, Coldbuster’s TK150-1050 under tile heater puts out 1050watts in its entirety. The heater covers a total area of 7m2, meaning the heater output is 150 watts/m2. If this heater was installed in a bathroom with a total area of 10m2, its output in relation to room area is 105watts/m2, which is an ideal value for the space. The 3-digit prefix in our under tile & carpet heater range indicates the output per square metre of the heater – e.g. TK150 = 150 watts/m2.

For Coldbuster’s in-screed heaters, the amount of wattage output per unit area depends on the cable spacing. Our recommended cable spacing for bathrooms is between 60 & 120mm. On average, this equates to an output per area of between 300 watts/m2 down to 150 watts/m2. In certain situations (e.g. in large living areas) we can drop the per unit output to below 150 watts/m2.

Rest assured that Coldbuster’s heating output ‘rules of thumb’ have been tried and tested over the last 20 years. By sending us a floor plan or diagram of your area, we can calculate the optimal output value for your space!