Calculator

Heat loss calculator

Quick estimate of your building's thermal demand in kW.

Enter basic building data: heated area, building type, insulation standard and climate zone. The calculator returns the estimated heat loss in kW with a split between transmission (walls, windows, roof) and ventilation. This is a preliminary estimate based on simplified coefficients. It does not replace full OZC calculations.

Heat loss calculator

Four basic building inputs, result in seconds. This is a preliminary statistical estimate using simplified coefficients.

How it works

  • Enter 4 basic building inputs: heated area, building type, insulation standard and climate zone.
  • The calculator applies simplified W/m² coefficients for the age and insulation category, then corrects the result for climate zone and building type.
  • You get the estimated heat loss in kW with a ±10% uncertainty band, a benchmark for your category, and a 70/30 transmission / ventilation split.
  • For full OZC calculations using the simplified PN-EN 12831 methodology (wall layers, windows, thermal bridges) use the HeatAlgo app.
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