I bought a roll of PETG for my Ender 3 and i am thinking it might be tough and flexible enough to survive fan duty... its really strong in the x/y plane but it doesn't bond layers super good so not as strong in the Z.
i have made some little airbox parts with it and its fuel/oil resistant. on my printer i run it at the very top end of the heat range to get the best layer adhesion. also warps like crazy so you need a glass bed.
if you wanna send me your model i can print ya one... its just the amazon basics brand and its pretty cheap but you'll need to do some dicking around to get the print settings perfect... print some small test pieces, haha.