AC Infinity CO2 + Light Sensor

A sensor measuring CO2 and light level, for the AC Infinity AI controllers. Range 0 to 40,000 ppm for CO2 and 1 to 65,535 lux for light.

Why CO2 and ventilation pull against each other

This is the problem the sensor exists for, and it is why dosing CO2 without measuring is money thrown away.

A plant builds sugars from light, water and carbon dioxide. In a closed room CO2 is often the first thing to run short: your plants take it out of the air and the concentration falls below what is normal outdoors. Enriching can then measurably speed up photosynthesis.

But your extraction exists precisely to exchange air. Every cubic metre leaving takes your CO2 with it. Without control you are doing two things at once that cancel out: dosing CO2 into a room that is blowing it straight back out.

On top of that, your extraction also controls your temperature and humidity, so simply switching it off is not an option.

With this sensor your AI controller drives air exchange on measured ppm rather than temperature alone. If your CO2 falls, enrichment can run; if your temperature climbs, ventilation can take priority. The two are weighed against each other instead of running independently.

What the light measurement adds

Photosynthesis happens in light. During the dark period your plants take up no CO2, so enriching then achieves nothing. Because the sensor also measures light, your controller knows whether it is day or night and can adjust its programme accordingly, without needing a separate timer for it.

Technical Specifications:

• Type: CO2 and light sensor, add-on module
• Model: AC-COS3
• Compatibility: AC Infinity AI controllers only
• CO2 range: 0 to 40,000 ppm
• CO2 accuracy: 50 ppm ± 5%
• Light range: 1 to 65,535 lux
• Features: day and night programming, environmental data logging
• Cable length: 3.66 metres

Frequently asked questions

Do I need CO2 enrichment?
Only if everything else is already right. CO2 helps once light, water, nutrient and temperature have stopped being the limiting factor. If something else is wrong, enriching gains you nothing.

Does this sensor dose CO2 itself?
No, it measures. Your controller can switch equipment based on the reading.

Does it work with the Controller 69 Pro?
No, it is intended for the AI controllers.

Where should I hang it?
At canopy height, and not right beside your extraction or your CO2 source, where you would measure an extreme rather than your room.

What does a range to 40,000 ppm mean?
That is far above anything you would run in a grow room. The range mainly tells you the sensor is nowhere near its ceiling at normal enrichment levels.