View Full Version : Exterior exhaust vent noise


Teken
04-28-2010, 12:25 PM
When it is moderately windy the outside the vent flaps open / close and I can hear this through the new over head range I installed a few months ago.

It is driving me crazy . . . What are some of the members tricks to reduce this noise?

I considered a few things:

1. Place one strip of tape on one side of all four vent grills. My line of thought was that the wind would have to pick up all four vent pieces rather than making just the one or two flapping in the air, causing the noise.

2. Install a few very small square rubber cushions under each plastic vent grill, and hope it reduces the banging?

Insight? :(

sickboi55
04-28-2010, 12:28 PM
no insight here. mine does it to, scares the hell outta me when it gets going really good.

Teken
04-28-2010, 12:38 PM
no insight here. mine does it to, scares the hell outta me when it gets going really good.

During the day it is what it is . . . At night, it scares the Beejesus out of me and the girls because sometimes it just bangs!

Help . . . :(

kbs2244
04-28-2010, 01:08 PM
It sounds like you are getting some type of ventri effect as the wind blows across the vent sideways.

Maybe a inch hole or two on the ends of the vent cover to let some wind in and cause some turbulence to mess up the vacuum.

Lippyp
04-28-2010, 01:12 PM
You could put a hood over it with an open bottom so the wind can't hit it directly.

rodnok1
04-28-2010, 01:19 PM
I'd use the rubber pads, also the hood is a good idea but most should have it on already. I had a bath fan vent that did that, I took the door off and made sure it had a screen on it, did make it a little drafty though. I wish they would tie them together and have a small spring to control the flapping myself....

Teken
04-28-2010, 01:22 PM
This is what I am dealing with. Perhaps this will give you all some more insight for ideas and suggestions.

I am not sure about putting a hole in one of the flaps, as I do not want any bugs crawling into the house.

http://i578.photobucket.com/albums/ss224/EVIL-Teken/DSCN5581.jpg

lawfarm
04-28-2010, 01:36 PM
I had that same issue on a house I used to live in...I tried a number of easy solutions, with minimal success. I ended up going out and buying/installing a new 'flapper'. The replacement one I bought featured one large flap (instead of 4 smaller flaps), and featured an angled hood/shield/roof on it. The combination of those two features eliminated the flapping in the wind. It looks like yours is installed in concrete??? If you can easily replace it, this is guaranteed to work. Mine was something like this:

http://www.airconditionerguard.com/images/5_10_small.jpg

But the hood wasn't quite that big, and it had a flapper inside. That does show you what I'm talking about though. If you can't easily replace the whole cover, maybe just custom fabricate a little shield for it out of sheetmetal, and paint it to match?

Teken
04-28-2010, 01:44 PM
Yes this stupid thing has been installed first, then the first coat of stucco applied in place. The second coat of stucco with color is being done next week, and I really wanted to take care of this before they come.

So I might use your idea, because if I wait till they do the second coat for sure there will be cracks where I pulled out the old one!

You wouldn't happen to have a brand and model number of that unit would you there Sir? What are the dimensions of that cover?

ddawg16
04-28-2010, 03:40 PM
You have an air leak somewhere......

The wind is entering your house somehow and using the vent to get out....

Find the leak and that should solve the problem.....I'm going to bet that it's somewhere in the attic....most likely related to your central heat/air.

Teken
04-28-2010, 03:47 PM
You have an air leak somewhere......

The wind is entering your house somehow and using the vent to get out....

Find the leak and that should solve the problem.....I'm going to bet that it's somewhere in the attic....most likely related to your central heat/air.

This is a direct vent straight from the other side of the wall (kitchen) to the outside . . . Sorry if that wasn't made clear before . . .:)

lawfarm
04-28-2010, 03:58 PM
You have an air leak somewhere......

The wind is entering your house somehow and using the vent to get out....

Find the leak and that should solve the problem.....I'm going to bet that it's somewhere in the attic....most likely related to your central heat/air.

DDawg,

This is what I thought when I first encountered this problem in my old house. I ended up testing the theory by completely sealing the vent on the inside, to block any airflow through it...and the issue remained. On that house, the vent was angled such that the prevailing winds caused the 'shutters' or 'flappers' to move under certain conditions. The shield was the only thing that solved the issue.

Teken,

I bought it at Menards, about 5 years ago, and installed it on a house I no longer own, about 30 miles away. So no, I don't have that info...:lol_hitti

Teken
04-28-2010, 04:02 PM
DDawg,

This is what I thought when I first encountered this problem in my old house. I ended up testing the theory by completely sealing the vent on the inside, to block any airflow through it...and the issue remained. On that house, the vent was angled such that the prevailing winds caused the 'shutters' or 'flappers' to move under certain conditions. The shield was the only thing that solved the issue.

Teken,

I bought it at Menards, about 5 years ago, and installed it on a house I no longer own, about 30 miles away. So no, I don't have that info...:lol_hitti

Oh great just dangle that carrot! :mad: I'll look around and see what I come up with, if I have to fab something up I will . . . As it was stated before this only happens when the wind is howling down the side of the house . . . :(

dodgepolara500
04-28-2010, 04:30 PM
That is a dryer vent exhaust. You need one that has a brow over it with a flapper inside. Given it is set flush, the stucco will lap over the edge. Try to install it proud about 1/2 inch

tonydanzah
04-28-2010, 04:33 PM
is there any monuments to alex trebeck in canada?

Teken
04-28-2010, 04:34 PM
is there any monuments to alex trebeck in canada?

What? Why? Did he die? :headscrat

tonydanzah
04-28-2010, 04:43 PM
no, but he is from canada...

Teken
04-28-2010, 04:44 PM
no, but he is from canada...

OMFG! :wtf: Please excuse me for a minute as I ask Shannia Twain to hold on, while I reply to your message! :spit:

Teken
04-28-2010, 04:45 PM
That is a dryer vent exhaust. You need one that has a brow over it with a flapper inside. Given it is set flush, the stucco will lap over the edge. Try to install it proud about 1/2 inch

When I have my one year review I think I might just ask them to replace the vent with something similar as to what you have indicated.

Because this thing isn't going to cut it . . . :mad:

tatra
04-28-2010, 04:59 PM
teken, don't mind tony, he's boning up on canada cuz he's trying to get on with a canadian railroad down in the states:lol_hitti.......neighbour has a couple of these on her house and they do the same thing........like the others said, a hooded one is the one ya need........mcdiarmid if ya have one, rona, h/d, truevalue, even can. tire should have something available.......possibly a roofing / siding supplier may also...........i wonder if you could tear the old one off and just throw a duct in there and apply after the stucco is done?.........

tonydanzah
04-28-2010, 05:14 PM
that and jeoardy was just on.

tatra
04-28-2010, 05:26 PM
how'd did it go?..........no not the show silly...........:lol_hitti

Teken
04-28-2010, 05:29 PM
teken, don't mind tony, he's boning up on canada cuz he's trying to get on with a canadian railroad down in the states:lol_hitti.......neighbour has a couple of these on her house and they do the same thing........like the others said, a hooded one is the one ya need........mcdiarmid if ya have one, rona, h/d, truevalue, even can. tire should have something available.......possibly a roofing / siding supplier may also...........i wonder if you could tear the old one off and just throw a duct in there and apply after the stucco is done?.........

These boners really have the thing cemented in place . . . I am not worried about taking it out right now, only after when the second stucco is put on later this week.

Then, if I decide to take it off it will for sure look like crap with crack marks! I will stop by HD, Rona, maybe Mcdiarmid for a look see . . .

Well Tony and I are in the same boat too then! Because I am trying to get on as well! :bounce:

tonydanzah
04-28-2010, 06:01 PM
haven't heard anything yet.

70redbee
04-28-2010, 08:47 PM
I have fixed many of these by glueing a penney to the backside of the flaps. Gives it a little weight to hold it shut but not enough to keep it from opening.

witchdoc
01-16-2011, 03:10 PM
This happens because of Bernoulli's principle.

High velocity = low pressure (and vice-versa)

When the wind kicks up and blows across the vent on the outside of the house a low pressure zone is created pulling air through the duct. It basically creates some vacuum in the duct. This simulates the "on" state of the fan. When the gust of wind stops the velocity of air by the vent reduces to zero and the pressure increases, thus suddenly stopping the flow of air and making the flapper close hard enough to be heard.

Same effect occurs when the shower curtain is drawn to you in the shower. The water jets from the shower head get the air moving, thus creating a low pressure zone in the show and drawing the curtain into the shower.

--info from another site that clarifys it nicely as not from air leaving the house

58Windsor
01-17-2011, 05:39 PM
An old post, but since it's been resurrected, I'll share the trick I used with our bath fans. Ours weren't flapping on the outside, but due to the venturi effect were making the one inside the fan housing in the bathroom itself pull open. As mentioned earlier, just weight down the one side of the valve a little and it should stop; tape on a penny or nickel, etc. My wife had a box of those thin magnets you use to cover the back of business cards; magnet on one side, adhesive on the other. Trimmed to fit & stuck it in place. Worked perfect.

djd99
01-17-2011, 05:51 PM
I haven't seen this mentioned yet why not put a dryer backdraft coupler in line.

http://www.amazon.com/Duct-Spring-Loaded-Backdraft-Damper/dp/B000VMCF2I