How much does underfloor heating cost to run?

Electrical cost

The cost of electricity for underfloor heating is influenced by two factors: the size of the area being heated and the wattage of the underfloor heating installed per square meter.

Heatwell installs underfloor heating cable at: 180W/m2 under slate, 150W/m2 under tile, 120W/m2 under engineered wood, and 100W/m2 under carpet and vinyl.

The formula is: (kW cost/(1000/W per m2))*m2 per hour. This formula assumes 100% run time, which is not realistic. A more realistic scenario is 60% run time.

For example: Electricity costs 21c per kW in NZ (available on your electric bill). Heating is under tile is 150m2. The area being heated is 3m2. (21/(1000/150)) x 3 = 9.445c. That's at 100%run time. 9.445 * 0.6 = 5.667c per hour is a more realistic electricity cost.