Grow Room Ventilation

Exhaust Calculator

Calculate extraction fan size in m3/h and CFM based on room volume, duct losses, carbon filter resistance, and heat load.

Inputs

Length (m)Width (m)Height (m)

Ventilation mode

Air exchange (minutes)

Fresh air: 2min | Temp: 1min | Full climate: 0.5min

Duct length (m)

90° bendsHeat load

Carbon filter (+20%)Summer / high ambient temp (+15%)

Temperature control mode

Replaces air 60x per hour (1 min exchange). Standard for temperature control in grow tents.

1,023 m³/h

602 CFM

Suggested fan range: 921 – 1,125 m³/h

→ Temperature mode: 60x/h • Heating/cooling

Room Volume

12.00 m³

Base airflow (no losses)

720 m³/h

424 CFM

Carbon filter

×1.10

Duct losses

×1.06

Bends losses

×1.06

Heat load

×1.15

Seasonal

×1.00

Practical tip

For quieter operation, choose a fan around 15-30% above recommendation and run it with a speed controller.

Airflow comparison

Fresh air only2 min = 30x/h

Temperature1 min = 60x/h

Full climate0.5 min = 120x/h

Formula used

Base m3/h = (Length x Width x Height x 60) / Exchange minutes, then multiplied by pressure and heat factors.