Do I need a mixing chamber?

Under normal circumstances you should not need a mixing chamber. The BIG BLUE is designed as an air purification chamber. As the odor-bearing air is exhausted from your grow space it is directed through the ducting and into the BIG BLUE. There, the air is exposed to high intensity ultraviolet light that kills viruses, odors and other volatile organic compounds (VOC’s)  on contact. The BIG BLUE’s polished stainless steel surfaces help to increase this intensity so that “baffling systems” and long lengths of ducting are not required. However, if you are using a BIG BLUE to control odor and the fan is perhaps too strong for the model you chose then the contact time may not be long enough. In this case, simply lengthening the duct run should be enough to sufficiently increase the contact time.