# Ridge Vent > Gable Vent



## jelly (Oct 19, 2007)

I've recently discovered that my ridge vent is not keeping my attic cool. My attic is about 700 sq and I have soffit around the entire perimeter. I decided to upgrade to a gable vent. Do I need to clog the ridge vent in order for the gable vent to work properly? Has anyone heard of modifying the ridge vent?


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## Ed the Roofer (Jan 27, 2007)

What brand, type or style of Ridge Vent do you have in place?

Is the vent slot cut out to the proper width?

Only one type of Exhaust Ventilation source should be used, so block the ridge vent slot if you are going to use gable vent fans. Otherwise, the theory goes, that the ventilation will be short-circuited.

Wait a minute. Is it plain old gable vents, or the gable vents with a fan and motor in it?

Ed


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## jelly (Oct 19, 2007)

Hi Ed, 

What brand, type or style of Ridge Vent do you have in place? *MASTER FLOW PG2
* 
Is the vent slot cut out to the proper width? *I just purchased the gable vent, I did not install it yet.*

Only one type of Exhaust Ventilation source should be used, so block the ridge vent slot if you are going to use gable vent fans. Otherwise, the theory goes, that the ventilation will be short-circuited. *Any ideas on what to block the ridge vent with?*

Wait a minute. Is it plain old gable vents, or the gable vents with a fan and motor in it? *It's a gable vent with a fan, motor and thermostat in it.*

Thank you


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## Ed the Roofer (Jan 27, 2007)

I am not familiar with the Master Flow PG2, so I will check it out later, unless you supply a link to it. I am sure I can find it easy enough.

You can probably use a hand stapler and shoot 3/8" staples int a double folded sheet of plastic visqueen just under the ridge vent slot to close it off since your gable vent is one with a powered fan.

Ed


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## jelly (Oct 19, 2007)

Thanks Ed.

http://www.doityourself.com/invt/6393391

http://www.homedepot.com/webapp/wcs/stores/servlet/thdsitemap_product_100088166_10053_10051


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## Ed the Roofer (Jan 27, 2007)

Thats why I did not know of it, because you were referring to a Powered Gable Vent.

I was initially asking you, "What Brand Of Ridge Vent" do you currently have on your home.

Some brands do not function as proclaimed. Most are the roll out versions, like Cobra Roll Vent or Roll Vent from Benjamin Opydyke.

They do not contain external wind deflecting baffles, like the Shingle Vent II Ridge Vent from Air Vent or the Cobra Snow Country Ridge Vent from GAF.

That gable vent you showed only has a thermostat for temperature settings. A preferable unit, from Air Vent Corp., would also have a Humidistat to expell the excessive humidity content built up inside and also function during the colder months when the thermostat will not kick on.

Ed


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## jelly (Oct 19, 2007)

The Master Flow is made by GAF so hopefully it is decent. Would you say most people have powered vents with a Humidistat?


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## Ed the Roofer (Jan 27, 2007)

Most people only know what Home Depot or Lowes sells, so No, they would not typically know about the humidistat versions.

I am sure it is a good temperature fan, but not functional for year round productivity.

Ed


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## wsuswim147 (Jan 12, 2008)

Ed

What if the gable vents did not have powered fans? Is the gable vent then not as effective as the ridge vent? Do gable vents need powered fans to work effectively.

Thanks


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## Ed the Roofer (Jan 27, 2007)

A gable roof with non-powered Gable Vents on opposing sides would need air to be blowing directly in the windward side and exhaust out of the leeward side.

Even under that optimum wind direction scenario, the cooler air that would enter the one side would ellipse downwards into the bottom of the attic floor until its molecules heated up and then began to rise again at the opposite side of the attic.

The hot air in the attic which has already accumulated and risen to the peal of the attic, probably would mostly be unaffected and be bypassed, so in essence, the hot air did not get expelled from this model. Only the new air flowing in and traveling under its wind current has passed through.

Ed


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## jelly (Oct 19, 2007)

It seems that spending $75 and an hour of time time is well worth if you plan to utilize the space in your attic. After ed's comments and doing a little more research, I've decided to return my powered gable vent and go with a powered roof vent. A CS rep at GAF said the best way to clog the ridge vent is with pipe insulation. 

Thanks again Ed


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