bathroom fans loud with foam insulation?
westmich
| Posted in General Discussion on
My home was built 6 months ago, and my attic has soft foam installed down on the drywall. My bathroom fans are very loud. The electrician has installed rubber washers to no effect at all. He has another new construction job with foam installed like mine and he has the same problem with noise.
We used can fans, which are supposed to be quiet ( I think they have a sound rating of 2). We had the NuTone rep at the house today and he has no idea what the deal is or how to address it.
They suspect it is because the insulation is covering the entire run of venting and creates an echo chamber of sorts, and their solution is to run the vents vertically out the roof instead of horizontally out the side/soffit.
Thanks a bunch for any insight.
Edited 12/8/2008 11:51 am ET by westmich
Replies
Fans typically make noise because of the air it is moving if everything else is running ok. If you want quiet, the Broan/Nutone QTXE series has a sone rating of 0.9 for a 110cfm unit, you can not hear it run. ALso, restricting the ducting say from 6" at the unit, to 4" for the run, will cause more noise. 2 sones is annoying to say the least, you may want to look into a new fan.
Thanks for the reply. Different fans are definitely an option, and I hadn't considered the vent diameter as a cause and the electrician never mentioned it. He and the NuTone rep are grasping at straws for a solution.
The application in the second story below the foam insulation is much louder than the same can fans in the lower levels. The same scenario is playing out at another home in the same situations. Makes me wonder if the foam insulation is not contributing to the added sound. It isn't normal fan noise--it is loud and vibrating, like a plane taking off. Can't even shower with the fan on because we get headaches from the noise. So it isn't just a factor of the fan's noise rating, though I may get a quieter one anyhow. I should have done my homework better--I asked the electrician for the strongest, quietest fan on the market and he gave me the can fans. I should have checked on my own, my bad.
I just checked pricing on the QTXE110FLT fan/light/nightlight, you don't want to pay any more than $180. That is the cadillac of bathroom fans in my opinion.
Thanks.
How to fix noisy bath fans:
View Image
Panasonic in-line unit. Mounted on a hunk of ply, over a hunk of foam, over the joists. Whisper quiet.
Mike Hennessy
Pittsburgh, PA
Great photo, Mike. I wonder how to retrofit when the attic floor is blown with foam. Cut out the foam and re-install the fan, then re-foam? It looks like you were about to insulate when you took the photo...
This house was just built, and I would not like to pour in additional money that I don't have anyhow! If this were your home, or a home that you built for a customer, who do you think would be responsible for the cost of getting this thing right? This may be a philosophical question and I don't mean to start any arguments, I am just stumped at this point. The fans are so loud that they rubmle, and they are not inexpensive units.
Edited 12/8/2008 6:52 pm ET by westmich
westmich,
I am in the electrical distribution business. If the units are making the noise you describe, they were either installed wrong, have a defect ( unlikely being's you have two doing the same thing ) or they have had modifications ( the foam over the pipe ) that is creating the noise.
Bottom line, it isn't or shouldn't be your fault. I would seek compensation from both the builder and Nutone, but I think the fix Mike shows, or the upgrade to the better quality QTXE series should solve your problem. We deal with these kinds of issues all the time, it is either us or the contractor eating the fix to keep the customer happy. It isn't right and you are due a fix.
Thanks for that response. I share that point of view, but I am constantly checking myself to make sure my ideas are not in conflict with prevailing practices by reputable contractors.
This fan was installed after the insulation. The insulation is cells, not foam, so I could just dig a hole, fit the pipe, and cover it back up. Photo was taken prior to insulating the piping and backfilling the cells.
You'd do the same with foam -- cut it out, fit the pipe, and fill back in with Great Stuff, or whatever foam you want to use. In your present condition, I suspect that the fan motor housing is vibrating the foam, which is vibrating the ceiling DW, etc. -- a giant speaker to amplify the fan sound. The remote-style units will eliminate that issue.
The Panasonic unit is great -- moves a ton of air and the only sound is the slight "whoosh" of the air moving through the vent. No motor sound at all. Can't hear it at all if any water is running in the room. I used this unit to run two vents in the room -- one over the terlet and one in the shower.
Mike HennessyPittsburgh, PA
What did you use for grills? John
I just used 6" round ceiling diffusers. If the fan box hole is already cut, I'd just install a boot and cover it with a std. adjustable louvered grille.
Mike HennessyPittsburgh, PA
Yep, electrician suggested a few in-line units to replace the can fans. More costly but well worth it. Thanks for the tip. Mike.
Glad it's working out for ya.
Mike HennessyPittsburgh, PA
Mike wrote:
>The Panasonic unit is great -- moves a ton of air and the only sound is the slight "whoosh" of the air moving through the vent. No motor sound at all. Can't hear it at all if any water is running in the room.The Panasonic Whisper-series cans are great, too. I believe my WhisperFit unit with two light levels was rated 0.6 sones for a 50 cfm unit; the new ones are down to 0.4 sones. I installed a rotary mechanical timer that was an extra from another job. The ticking of the timer how you tell the fan is on. (The second one has an electric timer...)It's even a model that fits in the 2x6 attic joist bay. The attic is finished so I needed to go out the gable side wall.When I went to the Depot, I thought all their fans were too loud. I couldn't imagine installing some of them in a residence - machine shop, maybe.If you don't need it to fit in a shallow joist bay, they make 0.3 sone models for $90 mail-order. I got my unit from http://www.hollywoodwholesaleelectric.com . Great mail-order company.---mike...
Madison Renovations
Cambridge, Mass.
Curious about the picture you provided.
I believe I see some of that aluminum insulation with the air gap in it around some of the straight duct work. Is that what I see, if so, do you find it works well in that application?
Not sure what you're seeing, but there was no insulation on the piping when I snapped the photo -- that came later. Maybe you're just seeing the aluminum tape used to tape the joints.
Mike HennessyPittsburgh, PA