What size fan should I use in combination with the BIG BLUE as part of an exhaust system for controlling odor?

If you’re using a fan to exhaust hot, stale air from the grow space then you should first choose a fan that will provide the proper number of air exchanges per minute to keep the room at the proper temperature and the plants happy. Then, choose a BIG BLUE that is capable of handling the CFM produced by that fan. E.g. If you’re using a 600 CFM fan, you will want to choose a BIG BLUE that can handle at least 600 CFM of air flow. We provide the maximum CFM each BIG BLUE model can safely treat in the product description pages for your reference. If your fan is greater than 2,000 CFM you may need to use more than one BIG BLUE.

If your goal is to eliminate odor that may be escaping from the room but you are not concerned about the amount of air your exhaust fan moves then you can get by with a much smaller fan. Here’s why…

Sizing a fan for the BIG BLUE isn’t like sizing a fan for a carbon filter. The most important factor is contact time. If you have a 5 CFM fan blowing through a BIG BLUE then you’ll have more contact time for the special UV light to kill odors, vs. having a 500 CFM fan blow through the same unit. It is best to use the lowest CFM fan available to accomplish this exchange. Watch this video for a deeper explanation on this.