Metric Republic / Building Physics & Energy / Building Heat Loss Calculator

Building Heat Loss Calculator

Estimate transmission and ventilation heat loss from envelope area, U-value, air changes and temperature difference.

How it works

Estimate transmission and ventilation heat loss from envelope area, U-value, air changes and temperature difference.

Formula:
Qtrans = A × U × ΔT; Qvent ≈ 0.33 × ACH × V × ΔT.

Before you use the result: Do not use simplified thermal or moisture estimates as a substitute for a complete building-physics assessment.

Practical use

Use verified material data and project geometry. Treat results as planning estimates and compare them with the energy/thermal requirements that apply to the project.

Keep units consistent with the source information.
Use project-specific densities, pack sizes and coverage rates where provided.
Round purchasing quantities to supplier packaging and delivery rules.

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