# Shingle Vent II vs Omni-20



## Cache (Sep 18, 2007)

Any preferences, or reasons for not using either?


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## MJW (Jan 27, 2006)

Omni because it doesn't have a baffle that will eventually clog with dirt.


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## Ed the Roofer (Dec 12, 2006)

I have never used Omni, but I believe that MJW once mentioned that it gets 20 square inches of NFVA per foot, while the other gets 18 sq in.

I have *Never* had a Shingle Vent II clog up with dirt or any other debris and I have done multiple follow ups several years and even a decade later to check functionality of that product.

Ed


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## jmiller (May 14, 2010)

You can't go wrong with SVii IMHO. Go to www.airvent.com and watch the smoke tests. Their design catches wind in a way that can vent twice as well as some of the others, so NFA does not tell the whole story. 

And that fabric inside them should be changed every time you change your furnace filter. :whistling


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## Ed the Roofer (Dec 12, 2006)

I believe that the Omni utilizes the same or very very similar design as the external baffle portion of the Shingle Vent II product.

The only thing I have ever seen entangled in the polyester filter on the bottom of the Shingle Vent II in some minor quantities is particulate from sawdust from cutting the slot across the ridge. But, it never seemed concentrated enough to considerably affect the exhaust ventilation flowage, in my opinion.

Ed


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## jmiller (May 14, 2010)

MJW said:


> Omni because it doesn't have a baffle that will eventually clog with dirt.


I've been in attics in winter and found a line of snow on the insulation directly below ridge vent. Supposedly that fabric is there to prevent that, though in this case(s) the vents were installed on lower reverse gable ridges that acted as intake for the higher ridge. Can't remember if it ever happened with shingle vent ii but it's likely, since none are any better than the other if they aren't installed right with balanced soffit NFA.


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## outlaw (Jan 7, 2009)

jmiller said:


> I've been in attics in winter and found a line of snow on the insulation directly below ridge vent. Supposedly that fabric is there to prevent that, though in this case(s) the vents were installed on lower reverse gable ridges that acted as intake for the higher ridge. Can't remember if it ever happened with shingle vent ii but it's likely, since none are any better than the other if they aren't installed right with balanced soffit NFA.


 
Ridge vent should not be install on any ridge that is 3 feet below the main ridge as it will be come an intake.


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## jmiller (May 14, 2010)

outlaw said:


> Ridge vent should not be install on any ridge that is 3 feet below the main ridge as it will be come an intake.


Unless the attic spaces aren't connected e.g. an overframed gable.


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## MJW (Jan 27, 2006)

I've seen plenty of them clogged with dirt. Cobra seems to be the worst, but have seen others clog up as well.

If snow is being pulled into the attic, there is a ventilation problem, not the product.

Both appear to be good products, but why take the chance of it clogging and not working. Omni makes other products also for more air flow if needed.


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## BarryBay (May 22, 2013)

*May home repair*



Ed the Roofer said:


> I have never used Omni, but I believe that MJW once mentioned that it gets 20 square inches of NFVA per foot, while the other gets 18 sq in.
> 
> I have *Never* had a Shingle Vent II clog up with dirt or any other debris and I have done multiple follow ups several years and even a decade later to check functionality of that product.
> 
> Ed


OWEN CORNING's ridge vents gives 20 sq in per linear foot:whistling also
:whistling


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## kubie (Oct 19, 2008)

we use Omni vent quit often. Gunnable and comes with 2 coils of 1 3/4" nails.


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