learn.howToCalculate

learn.whatIsHeading

A window heat loss calculator estimates the thermal energy lost through windows based on their U-value (thermal transmittance), area, and the temperature difference between inside and outside.

Formule

Heat loss (W) = U-value × Area (m²) × ΔT (°C) | Single pane U≈5.9; Double pane U≈2.8; Triple pane U≈0.9 W/m²K

Guide étape par étape

1Heat loss (W) = U-value × Area (m²) × ΔT (°C)
2U-value: single glazing ~5.8; double ~2.8; triple ~1.1 W/m²·K
3ΔT = Indoor temp − Outdoor temp (°C)
4Annual heat loss (kWh) = W × Hours/season / 1,000

Exemples résolus

Entrée

5m² double glazing (U=2.8), 20°C inside, 0°C outside

Résultat

Heat loss = 2.8 × 5 × 20 = 280W; annual (3,000 heating hours) = 840 kWh

Questions fréquentes

What is Window Heat Loss?

A window heat loss calculator estimates the thermal energy lost through windows based on their U-value (thermal transmittance), area, and the temperature difference between inside and outside. Use this calculator for accurate, instant results.

How accurate is the Window Heat Loss calculator?

The calculator uses the standard published formula for window heat loss. Results are accurate to the precision of the inputs you provide. For financial, medical, or legal decisions, always verify with a qualified professional.

What units does the Window Heat Loss calculator use?

This calculator works with inches, square metres, Celsius, kilowatts. You can enter values in the units shown — the calculator handles all conversions internally.

What formula does the Window Heat Loss calculator use?

The core formula is: Heat loss (W) = U-value × Area (m²) × ΔT (°C). Each step in the calculation is shown so you can verify the result manually.

Prêt à calculer ? Essayez la calculatrice gratuite Window Heat Loss

Essayez-le vous-même →