Originally Posted by
Glen Monaghan
Hi Raphael,
Yes, could use those two adapters, or similar, but I'm inclined to go with a single stage if I ever get around to "fixing" it.
As for impact of duct sizes, moving more air is expected with larger duct sizes but I'm surprised that your blower would draw more power with the larger duct because it should have less resistance than with smaller ducting.
When putting my filter unit together, foot print was far more important than height and, as it turns out, mine unit is 5 feet 2 inches tall (plus casters add another couple inches of height). The cabinet is set up for down flow, with a good bit of the top allocated to smoothly turning the air downward and spreading it evenly across the filter bed, then 4 filter trays, the fan, and then the exhaust chamber. I was originally going to exhaust straight down but thought it would be too restrictive because the bottom was only a couple inches off the floor (located in a carpeted area when I built this, but just moved into my new digs this last week and the flooring is smooth planking so would have been less an issue), and I didn't want the air blowing out the front. So, I side vent instead and have a curved baffle to help smooth the 90 degree turn.