This protection feature reduces the amount of air that moves which defeats the purpose of the older designs in the first place.
Power roof vents problems.
For proper ventilation both high and low vents should be installed.
One potential problem would be sucking moist moldy air up from the crawl space intothe house.
After that a different level of thinking is required.
In researching the topic of attic ventilation in the past i figured out the building code rules worked well for roof pitches up to 6 12.
Problems and solutions mixed exhaust vents.
Power vents shouldn t be used because they create more problems than they fix.
There is no risk of problems such a rust and bearing wear an tear as well when comparing it to other motorized ventilation alternatives.
By keeping your attic or roof cool and dry you will use less energy within your house to try and maintain a comfortable home without using external air conditioning equipment.
I would look at a lot of problems and instantly point to insufficient roof ventilation as the cause and recommend more roof.
Radiant barrier stapled to underside of roof.
I blogged about this earlier.
The research concluded that if a powered attic ventilator will be used there must be a good air barrier between the living space and the attic.
Roof vents and power roof vents are made to work in conjunction with vented soffits so that outside air will replace superheated attic air during hot summer days.
Because solar attic fans operate with a lower power output they are unable to move as much air as some of the other options that are available.
Insufficient ventilation can lead to moisture problems during the winter and decreased energy efficiency during the summer but too much ventilation can be just as bad if not worse.
According to the article powered attic fans can create excess moisture structural problems and combustion safety in a home.
Power attic ventilators can cause problems even without air conditioning.
These are real problems from real houses that have really happened.
Of course you try to make the attic scuttle hole use air tight trim on your ceiling cans but it would be foolish to ignore the benefits of a reasonably powered attic fan working in connection with adequate soffit venting.
I used to think roof ventilation was the cure all for everything.
That means you will need to double up your investment in this area.
Roof vents create an additional roof penetration essentially another place of vulnerability where leaks can occur.