you got two choices, my veg fridge, the one shown, has exhaust fans located in the fridge part, I used the stock freezer fan to push air in and around, there is also a small oscillating fan in there. Your other option is to keep it an enclosed system, to do this you just keep the freezer fan running (no exhaust hole in the fridge), you will need to mix a batch of yeast to create Co2 for the fridge, and then the smell and all is contained, this is the setup on the flower fridge and I use a cool tube to remove light heat. The fridge will get fresh air everytime you open it, Im in mine like daily. My temps sit in the 70's