I agree about it being silly that these new fans are not square, but from feeling the air (not using tools), it seems like at low rpm and low fpi there isn't too much backwash. Since you've got the tools, you might test with and without weather sealing around it to see if there's a noticeable difference. I will say that running an SP120 performance wide open had a significant amount of backwash on my 120.4 XT45.
post #21 of 22
2/20/13 at 7:18pm