What is the best CO₂ level for a greenhouse?

The enrichment sweet spot for most greenhouse crops is 700–1,200 ppm during daylight hours. At these levels, yield gains of 20–30% are well documented. The optimal concentration for growth is in the range of 700 to 900 ppm for most C3 crops including tomatoes, cucumbers, and lettuce.

Why does CO₂ drop inside a greenhouse during the day?

During peak photosynthesis on a bright morning, a healthy crop can pull CO₂ below outdoor levels — sometimes as low as 100–250 ppm in an airtight greenhouse. This starves the plants exactly when light is at its best, slowing growth and reducing yield.

How does VentPlus control CO₂ in a greenhouse?

VentPlus has two relays. One controls a fresh-air fan — which turns on when CO₂ drops below the depletion threshold or rises above the upper limit of your desired range. The other controls a CO₂ generator — which turns on when CO₂ sits below the lower limit of your desired enrichment range. All thresholds are user-settable.

Can VentPlus be used as a mushroom farm CO₂ controller?

Yes. VentPlus is widely used as a mushroom farm CO₂ controller across India. It maintains the precise CO₂ range needed at each growth stage — low CO₂ for pinning, moderate for fruiting body development, and higher tolerance during mycelium colonisation.

Does VentPlus work in polyhouses and vertical farms?

Yes. VentPlus is used in greenhouses, polyhouses, vertical farms, and plant nurseries across India. It is plug-and-play, requires no electrician, and works with existing ventilation fans and CO₂ generators via its built-in AC relay sockets.

VentPlus for growers

A greenhouse has the
opposite problem.

Name: VentPlus CO₂ Monitor and Controller for Greenhouses and Mushroom Farms
Brand: VentPlus

CO₂ Monitor & Controller for Greenhouses, Polyhouses and Mushroom Farms

For people, CO₂ is a problem to remove. For plants, it's food — and inside a closed greenhouse or polyhouse on a bright morning, a healthy crop can pull the CO₂ level in the air below outdoor CO₂ levels within hours. Growth stalls exactly when light is at its best, and like all CO₂ problems, it's completely invisible.

< 250 ppm Depleted — photosynthesis slows, growth stalls

~400 ppm Outdoor baseline — what your crop gets by default

~700 – 1,200 ppm Enrichment sweet spot — yields can rise 20–30%

Starving in plain sight

When the canopy pulls CO₂ below outdoor levels, photosynthesis slows, growth cycles drag, and produce comes out smaller and lighter — all without a single visible symptom on the plant.

Enrichment without measurement cuts both ways — too little wastes the opportunity, too much wastes the gas.

What depletion costs you

Slower growth cycles

Smaller, lighter produce

Inconsistent quality between batches

What excess CO₂ levels cost you

Wasted gas if enrichment runs blind

Higher running cost with no extra yield

Bumper harvest —
what steady CO₂ delivers

Commercial growers enrich because it works. The gains compound across every growing cycle:

Yield per cycle

+20–30%

Growth rate

Faster cycles

Crop quality

Consistent

Fuller produce

More photosynthesis means more biomass — bigger fruit, denser leaves.

Predictable batches

A held set-point removes the biggest invisible variable between cycles.

Gas used only when needed

Enrichment without waste — you pay for yield, not for gas that escapes through the vents.

Greenhouses Polyhouses Mushroom farms Vertical farms Plant nurseries

Same instrument, opposite job: feed the crop, don't starve it.

See the research on CO₂ & Greenhouse Yield

The VentPlus solution

The CO₂ monitor & controller for greenhouses —
maintain the CO₂ level that your crop wants

VentPlus CO₂ Monitor & Controller for greenhouses has two relays — 1. for ventilating the greenhouse (bringing outside air into the greenhouse to cover the CO₂ level deficit), 2. to turn on a CO₂ generator (a gas torch) to enhance the CO₂ level. It continuously measures CO₂ and switches on either the fresh-air fan or the CO₂ generator to maintain the CO₂ level in the greenhouse within a user-settable range. Works in greenhouses, polyhouses, vertical farms, and plant nurseries. Plug and play CO₂ controller with two relays.

Continuous monitoring

Real-time CO₂ tracking right at the canopy, all day.

Fresh-air fan — when depleted or above the desired range

The fresh-air fan turns on automatically in two cases: when CO₂ drops below the depletion threshold (350 ppm) — drawing in outside air (~400 ppm) to recover — or when it rises above the upper limit of your desired range (say 1,200 ppm) — venting the excess. Either way, it brings CO₂ back into the desired range.

CO₂ generator — when below the desired range

When CO₂ sits below the lower limit of your desired range (say 800 ppm) but still above the depletion threshold (350 ppm), VentPlus switches on the CO₂ generator until the level climbs back into the desired range.

No wasted gas, no stressed crop. All limits are user-settable.

VentPlus CO₂ monitor and controller installed in a greenhouse — The VentPlus controller switches dosing and ventilation equipment through settable CO₂ thresholds.

CO₂ Control for Mushroom Farms

Mushroom cultivation is uniquely sensitive to CO₂ — more so than any other crop. Unlike plants, mushrooms produce CO₂ and are harmed by excess of it. Each growth stage has a precise CO₂ requirement, and missing that window means poor yield, stunted pins, or open caps.

VentPlus is widely used as a mushroom farm CO₂ controller across India. The NDIR CO₂ sensor measures carbon dioxide continuously, and the relay switches your exhaust fan on or off to maintain the exact ppm range your mushrooms need at each stage:

Pinning stage

Low CO₂ (below 500–800 ppm) triggers fruiting body initiation. VentPlus ventilates aggressively to keep levels low and pins coming.

Fruiting body development

Moderate CO₂ (800–1,200 ppm) supports healthy stem and cap development. VentPlus holds the band with automatic ventilation control.

Mycelium colonisation

Higher CO₂ tolerance (up to 5,000 ppm) is acceptable here. VentPlus monitors and alerts — intervening only when needed.

Used in polyhouse mushroom farms, container farms, and dedicated spawn rooms across India — VentPlus gives growers precise, automatic CO₂ control for every stage of the mushroom life cycle.

A greenhouse has theopposite problem.