Bathroom exhaust fan problem: NuTone 9093WH

[oldberkeley]

I have a newer NuTone 9093WH circular fan/heater/light.

When the heater is not on, cold air pours through the vent into the bathroom.

How can I fix this? TIA

 

[Vegas_sparky]

The fan/heater/ light may have come with a damper in the exhaust housing. Its normally closed, until the fan is activated, and swings it open with static pressure. It may have been removed, or is stuck open. Oftentimes just pulling the ceiling trim allows you to inspect it.

If the damper is missing, or exhaust fan never had one, a new roof vent trim can be installed with an integrated damper. That should slow, if not stop, the cold draft from coming through the exhaust ducting.

 

[Sponsor]

 

[oldberkeley]

Thanks for your quick reply, a question about "pulling the ceiling trim":

I assume that you mean the round metal "cover" with the glass in the middle that is screwed to the housing????

If so, and after I do this I still can't see/find the damper, would getting up into the very narrow attic space above the fan do any good?

TIA

 

[JohnfrWhipple]

......would getting up into the very narrow attic space above the fan do any good?....

Only if you want to inspect the duct line without dropping the ceiling and re doing that later. If you can't move at all then a nice 18"x18" hole is a good size to view from.

Does your fan even have a damper? Why not look that up first.

 

[oldberkeley]

Incorrectly identified the manufacturer in my original post, it's a NuTone 9093WH.

I looked up the specs on the NuTone site, they do not list whether or not the unit has a damper.

?????

 

[JohnfrWhipple]

Incorrectly identified the manufacturer in my original post, it's a NuTone 9093WH.

I looked up the specs on the NuTone site, they do not list whether or not the unit has a damper.

?????

So if one is not there then you need to add a damper inline or like Vegas said one from the outside.... The ones we use are cheap. White or Brown. And install with four screws... Maybe $12.00

 

[oldberkeley]

John- I'm just saying that the specs on the NuTone site don't seem to go into that level of detail:
http://www.nutone.com/products/product/94825119-2ac2-4332-ad48-26867766d73f

This is a rather expensive unit: if dampers are standard, wouldn't this kind of unit have one?

-Gary

 

[JohnfrWhipple]

I made a choice about 13 years ago to work only with Panasonic. I have installed less than 4 NuTones ever.

I think the local Home Depot stocks them in a display. I would wait and call the tech line on Monday.

 

[oldberkeley]

John-

Yeah, we looked at Panasonic, they looked like great units but even more expensive than this NuTone!

Perhaps OT, perhaps not: even if we would have gone with a Panasonic, or something made out of solid gold, if the installer is an incompetent hack then most likely the whole job is going to be a mess. As an experienced pro you know that very well.

I was under a lot of stress, things were moving fast, I went with the rec of someone who as it turns out didn't know what he was talking about, and we've wound up with an entire $70K master bedrooom/bathroom addition that is a piece of crap. This guy was flat-out The World's Worst Contractor! I don't like to blame others for my own stupidity, so in the end, it's my fault.

As you suggest, I will call the tech line on Monday and let you know.

-Gary

 

[Vegas_sparky]

The dampers are typically a standard feature on modern units. Depending on how the installer plumbed the duct, he could have removed it, or its jammed open. If you pull the metal cover you should see the exhaust outlet, and the damper(flapper) will be right there. You might have to pull the exhaust fan assembly from the housing, which is usually very easy.

I don't see any benefit from going in the attic. If the damper isn't at the unit, its much easier to change the roof outlet. The roof outlet option also keeps the damper chatter on windy days less noticeable.

 

[hj]

The blower will be in the way of seeing the damper because it is located in the discharge outlet. Remove the blower and see if the damper moves freely. IF they twisted the outlet when they made the connection it is probably stuck open.

 

[oldberkeley]

OK guys, will do. Thanks much!

 

[Eurob]

Gary , I think you should check the wall / roof cap and see if you have a flap which should stay in a close position when the fan is not working .


This is how a typical installation should look like


----- The flap on the unit should be part #6 ------

 

[Cacher_Chick]

Even the panasonic damper does not seal well enough to prevent a back draft when the fan is off. I installed an inline damper in our main floor unit, and and outlet damper on the basement bath fan.

Depending on where your outlet is located, it might not be a problem in every installation.

 

[Terry]

The damper looks to be part 6 in the picture.

 

[JohnfrWhipple]

Even the panasonic damper does not seal well enough to prevent a back draft when the fan is off. .....

Really.

I have three in my home. Have installed close to forty of them in the past 14 years and have had 2 complaints. Both complaints where because the fan did not work. In both cases the fan was working and the clients simply could not hear it....

 

[Jadnashua]

It depends a lot on where the exhaust is, the prevailing winds, local obstructions that can cause swirling, eddies, low pressure or high pressure areas how much air moves through past the damper. MOst of them are a simple metal flap with the pivot point slightly off-center that relies on gravity to hold it in position, and opens when the fan is on providing positive pressure to swing it open. Most do not contain any gaskets, and can't be perfectly tight or they'd rub and possibly stick open or get stuck closed. As a result, they don't seal perfectly. It depends a lot on the space it runs through how cold it gets and the slope since the cooler air is denser, it falls.

 

[Steve Larson]

John-

Yeah, we looked at Panasonic, they looked like great units but even more expensive than this NuTone!

Perhaps OT, perhaps not: even if we would have gone with a Panasonic, or something made out of solid gold, if the installer is an incompetent hack then most likely the whole job is going to be a mess. As an experienced pro you know that very well.

I was under a lot of stress, things were moving fast, I went with the rec of someone who as it turns out didn't know what he was talking about, and we've wound up with an entire $70K master bedrooom/bathroom addition that is a piece of crap. This guy was flat-out The World's Worst Contractor! I don't like to blame others for my own stupidity, so in the end, it's my fault.

As you suggest, I will call the tech line on Monday and let you know.

-Gary

What everyone thinks is a damper on a Broan or NuTone is really a back draft preventer, and it does not do a very good job as a damper. Panasonic ventilation fans are even worst in this regard, when the flap is close, it still leaves good size gaps in the vent line. My company (larson fan) has a solution for this problem, a simple DIY upgrade to a true damper fan.

-Steve