Hey dude. Thought I'd check in with ya and give you a personal progress report. First, thanks for the design idea. This project wouldn't have came to fruition the way it did without you. I got it installed yesterday, and the second design was a winner for me. I COULD get by using the 170 cfm turbine fan and probably be ok, however, the other day I had my hydro gal order me a 6" inline turbine fan. CFM on it is around 450. I will go ahead and install it in place of the 4", run a 4-6 reducer into the carbon filter. I bet it will handle it with flying colors. The fan is controlled via a 5 amp reostat (ceiling fan controller). If I need to REDUCE the cfm, it should be a no-brainer. I am a little concerned about driving 450 cfm through the 4" pvc pipe. If memory serves me, isn't yours driven by a 6" turbine fan as well? If so, how much rpm you think your losing (cfm) when the carbon filter is connected? I know with my 170 cfm pushing through a factory Phresh 4", it reduces rpm and cfm substantially. With our home built unit, flow is substantially increased, and not a lick of odor, even with your nose right at the outlet. I just think maybe I'm pushing the envelope a little hard trying to ventilate the cab with the 170 cfm, ESPECIALLY when connected to a filter.
