I was wondering this as well. It seems like you would need a 3 inch grate for an 80mm fan, but NDS doesn't make 3 inch square ones. I wonder if a 4 inch grate would fit an 80mm?
picture shows an 80mm fan. according to google 80mm to inches is 3.15in. I have 2 120mm fans that are soldered together in the same line on a 12v adapter from a wifi router. they are only running half speed I figure. Intended to upgrade this but will be upgrading my entire environment next grow so it'll do for the time.
Kind of coming in here late with questions but would a single bend like this one block all the light? I am kind of tight on space and if this could work it would be awesome.
Many thanks for writing this guide!! I will admit I shamelessly copied your idea only slightly modified for my own use. Instead of the shower drain I used a white pvc toilet drain. I went with four inch piping and a four inch axial fan and everything bolted up perfectly with no drilling. You can find them in the plumbing section at any home depot or lowes. There isn't a grate on them like on yours but since you cut that out anyway that shouldn't much matter. There is a drain knockout plug that needs to be removed first. Its there to prevent things from falling down a toilet while you install it, but since thats not what we're using it for and it needs to be hammered out, I'd recommend removing it before you mount it. I used a second one as my through mount. I drilled the hole to the outside size of the nipple and screwed it to the back of the cabinet. A short stub of 4 inch pipe transitioned into the 90. I would imagine for a lower profile a 4 inch pulling 90 for electrical conduit would work very well, but at about $30 it isn't cheap. I also "borrowed" your cloner machine idea so I just felt the need to say THANK YOU!!