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I am having a new roof installed and there is an additional item Ridge Vents that I can add to the home - I currently have Gable Vents - no sofits.

I understand that the gables need to be blocked and Sofits added so that there is no short circuiting of air flow directly from gable to ridge.

My issue is this: After searching online for a comparison of energy savings - I get this "Ridge Vents are better and more efficient" Ok I would like to think so as well but I am having a difficult time with that statement. 1: Where are the facts and figures to prove out the efficiency and the savings ?

So here is my question does anybody have any figures , any calculations , any website links for an Actual Comparison of Energy Costs Ridge vs Gables - all things being equal .. same location (neighbors if you will , same cookie cutter suburbian dwelling..).

I am looking for real facts and figures - not um I think so's or seems liek it should be's ..

Any help is greatly appreciated ..

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  • Since you have not mentioned anything about any electrical device being used in the attic or space between the living space and the roof such as a fan, there should be no difference in energy consumption or usage.
    – d.george
    Sep 1, 2017 at 20:22
  • @d.george no electrical connection - but it is known that ridge vents properly configured with soffits ; allow natural convection to cause the air to rise from the soffit out of the ridge vents - so long as soffits are not blocked.
    – Ken
    Sep 2, 2017 at 7:45
  • @d.george By venting the heat in the attic, venting can reduce the air temperature in the attic. This is turn reduces the need for air conditioning - which can save a considerable amount of energy. Aug 20, 2019 at 17:29

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Neither is necessarily more or less efficient. Attic ventilation is a calculation of cubic inches of airflow, taking into consideration soffit venting and outflow.

There are lots of online calculators to determine this. Here's a link to the first one I found, from GAF:

https://www.gaf.com/Roofing/Residential/Products/Roof_Vents/Ventilation_Calculator

Depending on your area, ridgevents have just become a go-to for ease of figuring. That doesn't make it right, but it isn't necessarily wrong either. Down south where I live, you can't vent your roof too much. Up north, where heat retention may be an issue, proper venting may assist your attic insulation.

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  • that is a calculator for how much venting is needed per sq. Gable vents do not have natural convection - which is what makes ridge vents work better and the reason for the sofit - hot air rises and it will rise out of the roof by natural convection pulling in cool air from the soffit. Gable vents are on the ends they do not naturally create a cross flow of air. What I am looking for is details - how much energy will I save one method versus another method - where are the performance calculators?
    – Ken
    Sep 2, 2017 at 7:42
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    Actually, gable vents do have positive air flow, when use properly with soffit venting. The addition of ridge venting to gable venting negates the flow. What I'm saying is though, you are looking for performance, and it's not a performance thing. It's a right size, or wrong size thing. There is not a better vent, only a correct-size. Vents are not for super-cooling, only for .....well, venting.
    – NPM
    Sep 2, 2017 at 10:53
  • I was very disappointed with my ridge vents even with long open soffits with mesh but the ridge had a 2” coarse Matt to restrict rain flow but also restricts air flow. Even with 2 ft of blown fibreglass in the attic, the heat rise still demands the ACU to run nonstop in hot weather. From a thermal cooling efficiency point of view , roof collects a lot of heat (kW/m2) and higher air velocity flow is better not slow restricted convection. This needs good soffits with rafter ducts and lots of roof vents every 4ft or power assisted whirlybird. Aug 17, 2018 at 1:52

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