EDIFIS Group
YOUR HEATING PROJECT

The right heating output starts with your room.

Enter your room dimensions for an initial estimate. Adjust the insulation and temperatures, then prepare your request for advice from EDIFIS.

01Room dimensions

Measurements in metres. For an L-shaped room, calculate each rectangular area separately.

02Comfort and insulation

These coefficients are assumptions for the simulation and must be confirmed for your room. Glazing, ventilation and exposure can change the actual requirement.

The output is shared equally between the radiators. Their positioning still needs to be checked.

0 °C is a starting assumption to adjust to your local climate. Use a winter design temperature, rather than today’s weather.

03How many radiator sections?Optional
Understanding the calculation and its assumptions

The simplified method uses P = V × G × (Ti − Te), where V is the volume in m³, G is the heat loss coefficient in W/(m³·K), Ti is the indoor temperature and Te is the outdoor design temperature. No additional margin is added automatically.

Displayed outputs are rounded up to the next 50 W. The number of sections uses the calculated requirement before this rounding.

For the preset models, output is adjusted using Q = Q50 × (ΔT/50)ⁿ, with the exponent published by Fondital. Sections per radiator are calculated by dividing the room’s requirement by the number of radiators and by the effective output of one section, then rounding up to the next whole number.

The estimate does not calculate each wall, thermal bridge or ventilation flow separately and is not a regulatory calculation under EN 12831. For a hotel, large premises or a project with several rooms, arrange a sizing assessment suited to the whole building.

Sources for the method and technical data