Heat Gun Power Calculator
Estimate the electrical heat-gun (fan heater) power needed to warm up a space from room volume, target and outside temperature, and insulation quality.
How to Use the Heat Gun Power Calculator
- Measure room length × width × height to get volume in m³.
- Enter the outside temperature you expect to work in.
- Enter your target indoor temperature.
- Pick the insulation level and click Calculate.
使用场景
- •Sizing construction-site heaters.
- •Temporary heating for garages and workshops.
- •Drying plaster and screed.
公式
Rule-of-thumb: P (kW) ≈ V (m³) × ΔT (°C) × k, where k is 0.06 for poorly insulated, 0.04 for average and 0.02 for well-insulated spaces.
常见问题
Is this an exact calculation?
No — it is a practical rule of thumb that installers use for fan heaters. For a rigorous result use a full heat-loss calculation based on U-values and infiltration.
When is the "good" factor justified?
Only for sealed, insulated rooms — modern plastic windows, insulated walls and no large cold bridges. Construction sites and garages usually fall in the "poor" category.
Gas or diesel heat guns?
Convert the result from kW to fuel flow using the lower heating value: diesel ≈ 11.9 kWh/L, propane ≈ 12.8 kWh/kg. The kW figure itself does not change.