Hey I’m setting up a new 4x4 with a 6” ac infinity inline fan. I know this topic has been discussed here before but I didn’t find any answers specific to my situation. I can’t find a 6” duct vent hood for outside my house anywhere plus I would need to buy a $40+ 6” hole saw so I was planning on running everything 6” up until the point that I hook the duct to the 4” outside vent hood and reducing it to 4” there. Is this okay just being at the end of the duct run or will it decrease performance of the fan?
As others have said there are other options than a hole saw. A 6" hole saw is hard to handle with a light drill too. I just used a jig saw for most of it but couldn't cut close to the ceiling so used a drywall saw to do part of it. Use a compass to mark your hole area and make sure there's not a wall stud behind it before starting the cut.
Lining up the outside hole with the inside one can be tricky. I have some long smaller drills so once I had my centre inside drilled thru that centre to mark my centre on the outside wall. 6" thick walls too.
I also found a 6" aluminum dryer vent at the local farm supply and a plastic one at Home Hardware. Any building supply or HVAC place should carry them and the 6" hose to hook things up. Online for insulated hose if noise is an issue. Speed control helps cut down on the noise too. I also have a temp/RH controller on my exhaust fan so it only runs when it's needed.
For a 4x4' tent a 4" fan running half speed is good enough really.