power ventilators

[John Dirks Jr]

These round power ventilators you see on roofs. I see discoloring of the roofing materials surrounding them. I was just wondering, are these ventilators hard on the roofing materials?

[Jim Katen]

Originally posted by AHI

These round power ventilators you see on roofs. I see discoloring of the roofing materials surrounding them. I was just wondering, are these ventilators hard on the roofing materials?

Nah. It's just dirt.

- Jim Katen, Oregon

[BornaRoofer]

Unless its spitting out oils grease or other chemicals from inside.

[Jim Baird]

Some of the building science guys don't like those power ventilators, particularly on retrofits to older buildings, because they pull so hard the conditioned air sometimes gets sucked from the living space.

[Scottpat]

As Jim said, it is just dirt around the vent. It could also be rust or in some cases I have even seen soot from the ones that have burned out.

They are or were real common throughout the southern part of the country. The major issue I have with them is their lifespan. They just do not last in the southern heat. If you can get 3-5 years out of one you are doing good.

I seldom see them in the Middle TN area, but when I found them while in MS I would say that 75% of the time they did not work. Their motors were seized up.

[inspector57]

I seldom see them in the Middle TN area, but when I found them while in MS I would say that 75% of the time they did not work. Their motors were seized up.

Ditto in Texas, except the failure rate is closer to 99% due to heat.

Plus if you run the numbers, they don't really save any money. Give me an old fashion wind turbine any time.

[charlieb]

Originally posted by inspector57

I seldom see them in the Middle TN area, but when I found them while in MS I would say that 75% of the time they did not work. Their motors were seized up.

Ditto in Texas, except the failure rate is closer to 99% due to heat.

Plus if you run the numbers, they don't really save any money. Give me an old fashion wind turbine any time.

The manufactures say to oil the motor once a year. Funny how they can make it through the warranty period and then fail. Ridge vent are my preference. If a client is a die hard "burn some electricity" to make hot air rise kind of guy, I tell them to go to Granger supply and purchase a permanently lubricated BB motor for $100.

[Phillip]

Here lately I been seeing where some one has been coming in and adding power vents close to the ridge vent.

What a waste. This hurts more than it helps.

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[John Dirks Jr]

The power vent on my last inspection still had the cardboard packing materials inside the hood. They were blocking the screen.

[msteger]

CertainTeed requires removal of these during a re-roof with ridge and soffit venting to maintain the shingle's warranty. The other major manufacturers strongly recommend doing so also.

[Home Pride]

Originally posted by msteger

CertainTeed requires removal of these during a re-roof with ridge and soffit venting to maintain the shingle's warranty.

That's a rather specific warranty requirement, and I would like to see such a claim. Do you have any specs on that?

Dom.

[Mark P]

Here is one from today, where they did not even bother to hook power up to it. I'm sure it has been like that since the roof was installed in 2006.

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[Sodapop]

Originally posted by AHIS

Here is one from today, where they did not even bother to hook power up to it. I'm sure it has been like that since the roof was installed in 2006.

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They couldn't afford an electrician after having a new roof put on.