Old Bathroom Fan Dead...

[MatBirch]

Part of my rewire/rebuild attic access job this weekend was to diagnose the non functioning bath fan in the guest bathroom. Confirmed power and switch, so went ahead with rewiring it, along with the lighting and switches for the knob and tube removal.
Diagnosis on the fan is simply a dead motor. There seems to be a mountain of replacements available of many types. Mine is apparently a bit older than most, as I can't find an image that matches exactly. I'm more than capable of fabbing new mounts or brackets and installing a different style in there, but I'm wondering which is the best way to go? Maybe improve performance a little bit...

The existing is a duct mounted axial fan, about 5" in diameter. Most of what I find new, is either designed for an impeller blade fan, or a small squirrel cage.
My housing is simply a round duct, vertically oriented, with a gravity return flapper, exhausting pretty much straight up through the roof. The fan motor mounts on tabs up inside the duct. There is no square box/housing at all. The junction box is mounted to the outside of the duct, with a small curved access plate which also hold the plug on the inside.
I don't know if this arrangement allows for changing fan types, or if I should bother? I've played around with impellers before for a dust collection system, and the exhaust side exits 90 degrees to the intake. Squirrel cage blowers usually do as well, don't they?
Do these newer exhaust fans have more detail to the housing up above the ceiling? Exiting sideways? All bathroom fans ****, and rarely in the good way, but is one fan better than another? Worth screwing around with?

I'm sure I can find a direct replacement somewhere with enough looking. So far, I'm finding axial fan replacements are MUCH more expensive...

 

[gungatim]

mu

 

[BillK]

Look at Fantech A little expensive but great products. I have one of their inline fans exhausting the steam out of my spray washer at the shop and it has held up well for many years.

https://shop.fantech.net/en-US/products/c46709

 

[JRC3]

If you want to leave the old housing just remove the motor/blade, then install an inline fan in the duct itself. It will actually be quieter and probably stronger. If it is actually a 5" duct you may have to use adapters to go with a 4" or 6" fan. https://www.menards.com/main/heatin...3749027449.htm?tid=2737283513855176514&ipos=2

I've used radon fans for this in the past, but in a powder room with no moisture a cheap duct booster should do fine.


_________________

Since it sounds like you have attic access, I'd probably just gut the old and install a new. Might as well put a timer on it too.

 

[alfredeneuman]

Johnstone Supply should have it.

 

[samss]

If you are just replacing the motor:
https://www.supco.com/web/supco_live/products/SM670.html
Inexpensive and fairly uniiversal

 

[Bert_]

I usually order those little motors from grainger. Probably not the cheapest but they give all the measurements so you can get the right one.

 

[Norcal]

I usually order those little motors from grainger. Probably not the cheapest but they give all the measurements so you can get the right one.

Grainger is not cheap for sure but they usually have it, they stock motors for some 50+ year old fans I deal with, the motors are about $60 a pop now but easier then swapping the housing out.

 

[klassenl]

Bath fan replacement is not really our industry but we have to do it from time to time. When we get one like this we just replace it with a new one. It takes some effort. But it can be done without destroying the ceiling.

 

[MatBirch]

Thanks everyone! I'll probably just go with Grainger since I have an account. Can't really pout about $22...
Delivered tomorrow, and no driving around town.

 

[Jim greengo]

Picture of existing fan and motor?

 

[Lassen Forge]

I rebuilt mine - took the motor apart, cleaned 50 years of dust, dirt, and **** out of everything, checked the armature, polished and lubed the bushings, and gave it a test spin before I put it all back together... it's now become a "June job", I've gotten another 7 years out of the "shot" heater...

I *did* have to replace the switch, but got a few NOS switches via eBay, so I should be set for these for a centrry or 2 now...

 

[Bert_]

I rebuilt mine - took the motor apart, cleaned 50 years of dust, dirt, and **** out of everything, checked the armature, polished and lubed the bushings, and gave it a test spin before I put it all back together... it's now become a "June job", I've gotten another 7 years out of the "shot" heater...

I *did* have to replace the switch, but got a few NOS switches via eBay, so I should be set for these for a centrry or 2 now...

A lot of times I'll do that on my own stuff. If you catch it early enough it can last. If it's already worn it's a temporary fix. If you want to clean and oil you really need to do it before there is a problem.

For customer stuff I just order the new motor. Nobody is complaining about a $50 motor and I know I'm not getting called back in a year.

 

[The Cobbler]

looks like you've got it covered
you can usually find a replacement motor that will fit the housing on these things.
Short story, I replaced the motor on mine, it turned the wrong way so I endo'd the armature and put it all back together. couldn't figure out why it wouldn't **** LOL
I put the squirrel cage fan on backwards so the fan was covering the intake side ! LOL . flipped it around & all was good

 

[MatBirch]

Well thanks everyone! For the time being, I pulled it apart and cleaned it all really well. Polished up the shaft, and lubed the sleeve bearings. It's running well now. I will just monitor it for a while. The bathroom is due for a reno here in the coming years anyway, so I'll maybe look at a replacement fixture then.

 

[Jim greengo]

One of my commercial customers has a bunch of rental properties,one of them being an old brick apt building built originally in the 30s-40s I'm thinking.
Anyway on 1 of the apts I get called to for furnace issues.
(Nobody likes changing furnace filters) I was working on the furnace I could hear the exhaust fan in bathroom screaming like a banshee.
I told the renter to tell the owner about it and I'd throw a motor in it the next time i was there.
Over a period of 2-3 months i was in there a few times for differant differant things and kept hearing that fan,and i kept making a note about it on the bill when i mailed it in.
Well last week i got a call about a fire at that building,started in the bathroom exhaust fan in that bathroom.
I got temp power put in so they can work on the 2 apts,upstairs where fire started is a complete gut job ,apt under it will be about 1/2 gutted.
I'll get some pictures tomorrow.
Moral of the story is: exhaust fan motors are cheaper than burned up buildings folks!

 

[The Cobbler]

^^^wow, I thought they had thermal protection....

 

[Vtor]

If possible, replace with NEW - many new bathroom fan appliances for bathroom exhaust have over temp switch to cut power in event that motor binds and overheats. Poor maintenance also leads to lint and dust buildup - both very combustible.

Those fkn things like to catch on FIRE! Freak accident - nope, there's class action against the manufacturer.

By time smoke was in the adjacent bedroom (smoke detector), it had been burning for, what we guess was an hour or more.

 

[Jim greengo]

Expensive fan motor

 

[Bert_]

Most of the ones that catch fire give plenty of warning. I've been lots of places where you go in the bathroom, hit the switch and you just hear the fan going Mmmmmm without running.

 

[malibu101]

I've seen this disclaimer on Grainger's website recently about their motors that can be used for bathroom fans.

"Note: This product is NOT SUITABLE for any unattended equipment (including built-in bathroom exhaust fans), unless the listed Thermal Protection is 1 Shot."

Example- https://www.grainger.com/product/DAYTON-C-Frame-Motor-4M212?searchQuery=4m212&searchBar=true

 

[Jim greengo]

Most of the ones that catch fire give plenty of warning. I've been lots of places where you go in the bathroom, hit the switch and you just hear the fan going Mmmmmm without running.

Yep,customer has to listen when you tell them it's a problem though.

 

[JRC3]

Folks, that's another reason I mentioned the timer earlier.