For an indoor grow room the most popular ways of producing or releasing carbon dioxide (CO2) are to burn a fuel to manufacture it or disperse it from a tank.
CO2 is also a by-product of fermentation and organic decomposition of organic matter. Another method for producing CO2 is to use dry ice and let it set in the room, though dry ice can be hard to find and rather expensive to use as a source of CO2.
Indoor Grow Room CO2 Emitters
Compressed CO2 emitter systems are virtually risk-free and release no toxic gases, heat, or water with their use. These systems allow you to very precisely measure and deliver CO2 to an indoor grow room.
CO2 can be metered out of a cylinder by using a regulator, flow meter, or solenoid valve and a short-range timer for CO2 release. There are two (2) main systems for emitters; continuous flow and short range.
Carbon dioxide cylinders hold carbon dioxide, under 1,000 – 2,200 pounds of pressure per square inch (PSI) which is dependent upon ambient temperature.
These tanks are the same ones that are used to make pop or Coca-Cola in convenience stores, and restaurants and used by welding companies.
Carbon dioxide cylinders are available in three main sizes: 20, 35, and 50 pounds (9, 16, and 23 kg) cost approximately $100 – 300 for just the tanks and then they will need to be filled.
When you purchase tanks make sure the CO2 tanks have a protective collar on top to shield the valve from being damaged or broken since the tanks can LITERALLY fly.
If the tank is hit or dropped and you want to see you are losing CO2 then spray a soapy-water mix all around the valve as well as the container. If you see bubbles popping up you leak and should have the tank replaced.
If you purchase a cylinder, it does not mean that you will keep it because when you take it in to be refilled the tank is usually just exchanged for another one of the same size. If you are not able to carry much weight, you will probably want to use smaller cylinders so they will be easier for you to move and get refilled.
However, with smaller cylinders, you will have to replace them more often and have several more canisters to be sure to not run out. Purchasing a complete CO2 emitter is the best option rather than purchasing used and random parts to build one.
Carbon Dioxide Flow Meters
Flow meters reduce and control the cubic feet-per-hour (CFH) that is released, it is usually recommended to stay within the 10 – 60 CFH range for your garden. A regulator controls pounds-per-square-inch (PSI) dispersion.
Carbon dioxide is very cold when released from a pressurized bottle and can damage your skin or eyes if they come in contact as it is being released in your indoor grow room. If the flow rate is above 20 CFH then your regulator may freeze.
A regulator and flow meter are essential, but the solenoid valve and timer are optional though you risk wasting a lot of CO2, which is essential $$$ if you don’t use a solenoid valve and timer. A solenoid valve and timer can regulate the dispersion of CO2.
The solenoid valve runs electronically and is used to open and close or start and stop the flow of gas that comes from the regulator and flow meter. The least expensive timer is a plastic one that is commonly used in automatic sprinkler systems.
The more expensive timers are made of plastics and metals that are used for an indoor grow room. When you are choosing a timer, you will need to be sure to purchase one that has a short-range timing control.
Most timers come in 15-minute periods/cycles whereas more expensive ones have a digital control that allows you to time it down to the minute 24/7/365.
With a timer and emitter system, you can control the amount of CO2 being released into the garden by regulating the CO2 flow and duration period. An indoor grow room distributes the CO2 from the tank to grow room by using a tube or fan system that pours the carbon dioxide over the top of the plants or just into space.
Though be sure to not put the emitters too close to the plants as carbon dioxide is very cold and can harm the plants if it falls immediately on the plants in your grow room. You will want to give some space between the emitters and the plants for the carbon dioxide to warm up a bit before landing on the plants.
Many times, an indoor grow room will use a larger tubing connected to the emitter system then branch off to a manifold system where they will use a whole bunch of smaller tubes to branch in and around the indoor grow room.
Remember that CO2 is heavier than air and will fall to place the emitter tubes higher in the ceiling to be able to adequately reach all parts of the plants. You will want to test if the CO2 is dispersed evenly within your room.
By punching emission holes in the plastic tubing underwater while the CO2 is on to see if, and how much, CO2 is being released from each tube in the system.
Having overhead circulation fans will help to distribute CO2 evenly throughout the indoor grow room and around plants. Compressed CO2 is expensive and most typically used in smaller grow rooms.
With large indoor grow rooms it is more cost-effective to use CO2 generators to produce carbon dioxide. With compressed CO2 emitter systems cost more upfront to set up and maintain, but it is often best to use a natural gas or propane CO2 generator.
Let us know what you think.