Agriculture Reference
In-Depth Information
Ventilation
After deciding what kind of lamp to use when growing cannabis, it is important to consider
what kind of ventilation to use. It is important to have sufficient airflow to support the can-
nabis plant. Not only is the cannabis plant expending oxygen which needs to be replaced, it
is also in need of air circulation to protect itself from mold.
If you have decided to use an HPS lamp when growing cannabis, it is extra important to con-
sider heat management. It is recommended to invest in an extractor fan system regardless of
the lamp used; however, it is extra important when using an HPS lamp.
If you are using for instance a 600w HSP lamp, the heat expenditure needs to be combated in
regards to the growing area. The extractor fan system needs to be large enough to exchange
the total volume of air in the room every two minutes. For a grow tent (or room) with the di-
mensions 47”x47”x79, the total volume of air is 2.86m3. Changing the volume of air every
two minutes requires an extractor fan which has the hourly capacity of 2.86x30, this equals
85.8 m3/hr. If you are using an HID lamp, the heat expenditure doubles the amount needed
for air exchange.
Use this formula to calculate what fan that is needed for your grow area, and find a suitable
ventilation system. Cannabis has a tendency to smell a lot and it is vise to also buy a carbon
filter letting your extractor fan suck the air through it eliminating the odor, the ventilation
system will also require ducting for the air outlet.
