Hello, due to not wanting to get any hassle from my neighbours, I am currently building a 'sealed' cold smoker with a filter to prevent any smoke discharge. I have currently built a 6 foot tall, by 4 foot wide and 2 foot deep cold smoking chamber. This is roughly based on a vertical forced air commercial style smoker. I have fitted 5 lengths of pipe across the bottom and top of the smoking chamber (see attached pic), with holes drilled every 2 inches. All the pipe ends are connected to a manifold box with a fan in between the top and bottom set of pipes, so the smoke comes from the bottom pipes and is drawn in at the top of the smoker, through the fan and back out the bottom again. I had to make a stainless smoke generator like the Amazen style 12 inches square because I couldnt buy one this large. This will be fitted in a stainless box on the outside of the smoking chamber, with a small 5 cfm fan pulling the smoke in the chamber. Once in the chamber it will then circulate as described above. To remove the stale smoke, I'm fitting another 5 cfm fan to a filter unit. It consists of firstly a wet scrubber, then going through a carbon filter. I am thinking about putting a hepa filter between the wet scrubber and carbon filter. I was just wondering if anyone has built a similar commercial style cold smoker to this, and what flow rates they have used in the smoke circulation fans? Also has anyone made a filter like this and had success?