[retired guy 60]

My friend needs a new roof on her home. One side of the roof has standard ashalt shingles and the other side, where an addition was built, has a flat roof. Her roofer wants to put in a power ventillator with no ridge vent but I feel that the combination of soffit vents plus a ridge vent is the better way to go. Since he is a professional his opinion has a great deal of weight. What do you think? I will print the responses and show them to her to suggest the best way of dealing with this.

 

[retired guy 60]

Just to be clear... I do not recommend a power vent plus the ridge vent. I favor the ridge vent w/o the power ventillator.

 

[Slyfox]

Proper roof ventilation requires three steps:
1. Intake
2. Unobstructed flow
3. Exhaust

If there is proper intake ventilation and unobstructed interior air flow than the ridge vents are the most sufficient method of providing exhaust ventilation.

If there is an issue with either the intake or unobstructed flow and your friend is not/can't spend the additional cost to correct the issue than the power vent would be the better option because it will force air movement.

 

[Ed the Roofer]

Retired Guy,

Your recommendations are right on the mark.

To further expand on what Sly has mentioned though, using a Powered Attic Vent, if there is NO intake, will wind up eventually costing more money, because the air will be sucked out of the conditioned interior living spaces through many areas of bypass and also the motor will be overworked to the point of straining and burning out prematurely.

Ed

 

[retired guy 60]

Thanks to Slyfox and Ed for the prompt responses. Makes sense.

 

[deeze]

My house has three gables - two of which have a 12"x8" vents - the third has a powered thermostatically controlled fan. Keeps my attic very cool... relative to the 3000 degree Florida sun. This will probably go away when I get a new roof and get a ridge vent.

Prior to this installation my attic timber would get so hot it would burn my hands and make it impossible to be in the attic... pheww

 

[Ed the Roofer]

My house has three gables - two of which have a 12"x8" vents - the third has a powered thermostatically controlled fan. Keeps my attic very cool... relative to the 3000 degree Florida sun. This will probably go away when I get a new roof and get a ridge vent.

Prior to this installation my attic timber would get so hot it would burn my hands and make it impossible to be in the attic... pheww

Although I am a strong proponent of using Ridge Vents, especially the styles that have the External Wind Deflecting Baffle incorporated into their design, why mess with a system that seems to be working adequately?

Yes, a passive ridge vent system, which does not depend on any electricity will save you on energy bills, but you should determine which would be more efficient for your home first, before you decide.

Ed