Because Christmas is hot, we need to vent our enclosures down here in the southern hemisphere. Until this year I had simply used a cheap 90 degree pipe with a fan inside the box to expel cool air, but the pipe stuck out a long way and looked messy.

So, I have a 3D printer, and got bored one evening, and in 15 minutes knocked up a design for a much nicer, and lower form factor, vent, that still maintains its weather resistance. The 2 piece design has an external section and internal section (I dont yet have them screwed together, but I may do that in the future). The external section can have some flyscreen taped at the base, as shown, to stop small bugs going in when the box is powered down, and the internal piece will allow a 60mm fan to be glued in place.

A big helping of silicone behind the external piece will be enough to keep water from flowing behind it and into the box, but the 50mm diameter pipe, once sealed on the inside too, will also help keep water out.

It's a bit of a challenge to print, but it can be done vertically, or flat as shown in the 3D Render with support below it. 10% support infill with lines 90 degrees apart give a great support base and does not waste much filament at all.

NOTE: There are 2 widths included. The narrower one is the standard one, but I needed to fill in some wider holes when replacing the old conduit bends with these ducts, so the wider one was created