Formula & worked example
Q=ρ·cp·Vdot·ΔT·(1−εHRV).
500 CFM outdoor air with 20 K ΔT is about 5.7 kW sensible load before recovery at standard density.
Heating & HVAC engineering calculator · Updated Sep 17, 2026
Ventilation Heat Loss Calculator — Airflow, ΔT & Heat Recovery
Calculate sensible ventilation heating load from airflow and temperature difference, including heat-recovery effectiveness.
Inputs
Live result
Temperature difference 20 K
Gross sensible load 5.6973496 kW
Recovered heat 3.9881447 kW
Net ventilation load 1.7092049 kW (5,832.0491 BTU/h)
Assumptions & limits
- Sensible load only; latent moisture load is separate.
- Density and heat capacity are explicit inputs.
Frequently asked questions
What does this Ventilation Heat Loss Calculator calculate?
Calculate sensible ventilation heating load from airflow and temperature difference, including heat-recovery effectiveness.
What units are supported?
Inputs state their unit basis and results include practical SI and US customary equivalents where useful, so the calculation can be checked against field data and equipment schedules.
Can I use this for final equipment selection?
Use it for transparent first-pass sizing and engineering cross-checks. Final selections should use measured conditions, manufacturer performance data and applicable codes or design standards.