I *did* RTFM; the FM is AFU

[bunsen_h]

I'm trying to install a new bathroom fan.  The spinning part of the old unit gets loose on its axle and develops loud and complex beat patterns.  ("RA-ta-ta-TA-ta... RA-ta-ta-TA-ta... RA-ta-ta-ta-TA-ta-ta-ta-RA-ta-ta-ta-TA-ta-ta-ta...")  The new unit is much more sturdy and appears to be better constructed, with a more solid motor.

But the installation isn't going according to the manual.  This is because the instructions appear to be impossible to follow.  Since the joists are 16" apart (center to center), I'm apparently supposed to use wood screws to attach the fan to two of them... but the screw holes in the fan are only 11" apart.  I'm also supposed to slide a support strut into the body of the fan, but the instructions don't tell me to attach it to anything.  It also appears to be physically impossible to either insert the fan body through the hole in the ceiling with the strut already in place, or to slide the strut into its place after the fan has been pushed through the hole.  The strut would have to pass through either the ceiling or the joist.

I'm currently leaning towards cutting a couple of short lengths of 2-by-4, and screwing them to the joists so I've got solid wood on either side of the fan to screw it into.  And forgetting about that strut.

Is this another case of a company providing impossible-to-follow instructions so that if there's a problem, it's not their fault?
 

Comments

[henrytroup.livejournal.com]

those short pieces are necessary, in my experience. last time I changed the bathroom fan, i wound up installing the motor and blade of the new fan into the housing of the old one, but that was because of a ducting issue.

[bunsen-h.livejournal.com]

I'd intended to replace only the contents of the housing, but it turned out that the newer version of the old fan isn't compatible with the housing... or at least the insides can't be swapped easily. I'd have had to pull the old housing out of the ceiling anyway, so I decided to buy a better, quieter model.

I wonder if it would be worth while adding a thin layer of fabric between the fan's flange and the ceiling, to reduce the acoustic coupling?