by Drees R. Oellerich, ChopperLight.com, Berlin, Germany
The common way to deliver increased CO2 to plants is to elevate the CO2 content of the entire grow room atmosphere. This procedure depends on air tides or fans in a closed and sealed room structure to deliver the CO2 evenly across each plant. While easy in small rooms, in industrial-scale grow rooms this becomes problematic.
By calculating the required volume of CO2, it is obvious that most of the CO2 enriched air is wasted on the room space itself and is not used in the narrow surrounding area of the plants. Different circumstances favor CO2 loss, such as open doors, leaking AC and the wide-ranging leakage of the culture room.
To reduce the amount of CO2 required, ChopperLight designed and constructed a closed cycle atmospheric system called the CO2 BagSystem. This construction allows a controllable and constantly CO2 enriched air flow, on a large scale and expandable structure.
Our client, Tissue-Grown Corporation in California, US utilized the first demo grow-shelf with an actual capacity of 15 separate sizable bags, and a total of 30,000 plants. The main air-stream pipe has a total length of 100 feet, and is powered by one in-duct air blower. A special pipe construction arrangement equalizes the atmospheric pressure and air flow rate on each bag connection. The CO2 loss, compared to the previous CO2 room system, was already reduced by over 70%. The CO2 amount in each of the attached grow bags, independent from individual plant CO2 absorbance, varies only by a very small amount and is homogenized every 1-2 minutes.
To control and automate the addition of CO2, we had to find reliable and accurate sensor technology. It was very important to use CO2 sensors that easily integrated to our existing controls for temperature and air-blower regulation system. For this reason we decided to use CO2Meter's K-30 Series technology and the TIM10 Desktop CO2 meters. This technical high quality and versatility, combined with the professional support we gained, were key factors leading to success of this project.