Panasonic Vent Fan Installation

[FJK]

I'm remodeling my upstairs bath room & want to replace my existing bath/light ventilation fan with a Panasonic unit I just bought, model FV-11VQL4. I figured this is the time, because the ceiling drywall opening is completely different from the old fan to the Panasonic. So, ceiling drywall patching will be in the cards.

First problem, although there is an attic above the bathroom, I really can't get to the fan because the roof slope is so low at that point, I'm thinking I can get this from below, as long as I cut out enough ceiling drywall.

The real issue is the mounting instructions which gives 4 mounting variations. The fan housing is rectangular, with about a 1" flange around the perimeter. One mounting variation shows screwing the flange to the bottom of the ceiling joist & presumably you would drywall over the flange. The housing would then be recessed from the drywall ceiling by the thickness of the drywall. Other mounting variations show the housing protruding past the bottom of the ceiling joist by 7/8". This would have the entire square flange standing proud of the finished ceiling & basically sounds wrong to me. Maybe it would make sense if you cut a fresh opening into a finsihed ceiling, but that won't work for me because I have to mount this from below with exposed ceiling joists.

Anyone install a Panasonic fan/light & can offer some guidance?


Thanks, FJK



Installation instructions

[drick]

You are forgetting about the strapping between the ceiling and the joist. 7/8" below the joist is still above the edge of the ceiling. If for some odd reason this isn't the case raise the housing until it is flush or a little higher then the edge of the ceiling.

Also the hole you make for the housing should be completely covered by the grill when completed so there should be no need for sheetrock repair.

The bad news is you may run into a problem removing the old fan if you do not have access from above. Usually the fans are nailed to the joist before the ceiling goes up. You will not have easy access to the nails from below it. Your best bet may be to push up on the old housing so that the edge of the housing away from the joist is above the sheetrock and then try prying it off the joist. Just guessing though since I'm not there.

And make sure you vent it to the outside!

-rick

[hj]

Does the trim ring mount in such a way that it would "cover" the part of the flange below the ceiling. From your description it appears that the range is from flush with the joist to 3/8" past the drywall. If that is the case, just use an inbetween dimension and put it flush with the sheetrock.

[Terry]

You can mount the outlet plate to the wood structure from below, and then lift the fan case up to the ceiling and click it on.
The flange stays below the ceiling, the cover is large enough to cover.

Installation instructions

I have the same thing in my bathroom.
All I install are Panasonic fans now.

[FJK]

Yeah, I think I figured this out. The instructions are so extensive for multipe mounting options, it took me some time to figure out what they are trying to tell you. Since I can't get to the existing fan from above, due to the low roof height in the attic, I'll pull down the drywall ceiling between 2 ceiling joists & work from the bottom, inside the room. I'll attach the duct adaptor the way Terry described, then mount the housing. The underside of the housing flange will then be on the face of the finsihed drywall ceiling on 2 sides of the housing. Then, a new piece of drywall will pick up the other 2 sides of the housing, also going under the flange. In the end, the housing flange will be flush to ceiling drywall on all 4 sides.