Free calculator

Grow room CO₂ calculator

Enrichment is two problems: the one-time charge to raise the room to setpoint, and the continuous top-up that replaces what leaks out with every air exchange. The leak usually costs more than the charge.

Room & setpoint

LengthftWidthftHeightft

Ambient / starting CO₂ppmOutdoor air is ~420 ppm.Target CO₂ppmAir exchanges per hourACHSealed room ≈ 0.5–1. Anything with an exhaust fan running is far higher — enrichment fights the fan.Injector / generator rate (optional)g/h

Result

Room volume 800 ft³ (22.7 m³)

CO₂ to raise room 420 → 1,200 ppm

32g

= 0.07 lb of tank CO₂

Ongoing loss to air exchange

32g/h

≈ 1.7 lb/day held at setpoint

Time to setpoint at injector rate

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Enter an injector rate to estimate this.

A 20 lb tank (9.1 kg) holds setpoint for roughly 11.7 days, plus another 32 g each time you vent and re-enrich.

Plants consume CO₂ too (roughly 20–50 g/h per kW of light at full canopy), so real usage runs above the leakage-only estimate. Never enrich an occupied sealed room without a monitor — 5,000 ppm is the workplace exposure limit.

Exhausting air you just enriched? Check your fan CFM →