How to calculate the power of an electric underfloor heating system

Correct power calculation is the foundation of an efficient and economical underfloor heating system. A system that is too weak will not heat the room, while an excessive one will lead to unnecessary costs. Let's break down how to calculate the power of an electric underfloor heating system step by step.

Step 1. Determine the effective area

Underfloor heating is installed only in open areas – where there is no furniture or appliances standing flush with the floor (cabinets, sofas, refrigerators). This usually accounts for 70–80% of the total room area. For example, in a 10 m² room, the effective heating area will be approximately 7–8 m².

Step 2. Choose the type of heating

The required specific power (W per 1 m²) depends on the purpose:

• Comfort heating (floor as an additional heat source, main heating from radiators): 100–150 W/m².
• Primary heating (underfloor heating as the main heat source): 150–200 W/m².

FTMAT heating mats have a power of 150 W/m², which is suitable for most rooms.

Step 3. Calculate the total power

Multiply the effective area by the specific power. Example: 8 m² × 150 W/m² = 1200 W (1.2 kW). This is the peak power – actual consumption is lower due to the thermostat, which switches off heating when the set temperature is reached.

Step 4. Select a kit

Based on the calculated area, select a heating mat or cable of the required size and a thermostat rated for this load (most models are up to 16 A, approximately 3.5 kW). For installation in screed, use a heating cable; for installation under flooring without screed, use a heating mat. Don't forget the thermostat.

Summary

The calculation boils down to a simple formula: effective area × specific power = total power. If you don't want to calculate manually, provide us with the room dimensions and heating type, and we will select the appropriate kit. Delivery throughout Tashkent and all of Uzbekistan.