Need some schooling on Roof fans....

JC1

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6,110
Location
Oshawa, Ontario Canada
These are the vents on each side of the house. They seem quite small to me. Working on a roof picture (need a new ladder)
Those tiny slats won't do much. Thanks for the pic.

I have a 8*12 shed. Originally I installed one 4 ft ridge vent in the middle of the roof. Shed has soffit vents on both sides of the gable roof. In summer when it was over 100 degress it was very hot inside when the door was closed. I decided to remove the one 4 foot and expand it to three 4 foot ridge vents for almost the entire length of the shed less 6 or so inches at each end of the roof peak. Temps in the summer dropped at least 10-15 degrees F.
 

JTK

Messages
13,518
Location
Buffalo, NY
Not only are roof vent fans adding more potential leak points to your roof, the fans motors in them are absolute junk. I have several family members who's homes had them from day one. They get replaced when the roof gets replaced and the motors in them last 4yrs at best. If I had to do a fan, it would be a gable fan or a whole house fan that draws air in through the windows and blows it up into and out of your attic space.

FWIW, I just had a metal roof installed on my home by the Amish. At this point I'll never do shingles again and don't see the point in them. With the Amish, it cost me about 30% of what any local big boy outfit would charge. It turned out awesome.

Luckily my home has full vented soffit with baffles between every roof rafter and full ridge vent. About a foot of blown in insulation on the attic floor. It's a total nightmare up there trying to figure out where bath fans and wiring are. You cant see anything but a sea of blown-in insulation and some daylight thru the soffit baffles and ridge vent.
 

JC1

Messages
6,110
Location
Oshawa, Ontario Canada
Luckily my home has full vented soffit with baffles between every roof rafter and full ridge vent. About a foot of blown in insulation on the attic floor. It's a total nightmare up there trying to figure out where bath fans and wiring are. You cant see anything but a sea of blown-in insulation and some daylight thru the soffit baffles and ridge vent.

That's the way it should be for optimal performance of your roof and attic space.
 

daves87rs

Thread starter
Messages
18,614
Location
Michigan
Those tiny slats won't do much. Thanks for the pic.

I have a 8*12 shed. Originally I installed one 4 ft ridge vent in the middle of the roof. Shed has soffit vents on both sides of the gable roof. In summer when it was over 100 degress it was very hot inside when the door was closed. I decided to remove the one 4 foot and expand it to three 4 foot ridge vents for almost the entire length of the shed less 6 or so inches at each end of the roof peak. Temps in the summer dropped at least 10-15 degrees F.

Thanks, that is what I was thinking as well. I feel I need a few 3-5 foot Vents on each side at minimum. I think it would increase airflow 2 to 3 times what I am getting now. Pretty sure the house would stay much cooler as well......
 
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daves87rs

Thread starter
Messages
18,614
Location
Michigan
Not only are roof vent fans adding more potential leak points to your roof, the fans motors in them are absolute junk. I have several family members who's homes had them from day one. They get replaced when the roof gets replaced and the motors in them last 4yrs at best. If I had to do a fan, it would be a gable fan or a whole house fan that draws air in through the windows and blows it up into and out of your attic space.

FWIW, I just had a metal roof installed on my home by the Amish. At this point I'll never do shingles again and don't see the point in them. With the Amish, it cost me about 30% of what any local big boy outfit would charge. It turned out awesome.

Luckily my home has full vented soffit with baffles between every roof rafter and full ridge vent. About a foot of blown in insulation on the attic floor. It's a total nightmare up there trying to figure out where bath fans and wiring are. You cant see anything but a sea of blown-in insulation and some daylight thru the soffit baffles and ridge vent.

I do like the Amish idea...... :)

The more I learn, the more I think more vents are the better solution than fans. I have heard stories that were not good as well. A neighbor mentioned his china made vent fan barely made two years......
 
Messages
5,120
Location
Pittsburgh,PA U.S.A.
You can buy the fan with on outside housing at Home Depo and other similar big hardware stores. However the small motors that these fairly big fans use are made as cheap as posable and are extremely inefficient. I saw one that was rated at 1/10 HP (which is 74.57 watts if the motor was 100 percent efficient) draw 8 amps as its continuous amount of running current (not starting current), on 125 VAC rms. That is 1000 Watts. That is 7.457 percent efficient, which is terrible and cost a lot to run. If it were not for the fact that there is a lot of air going over and through these motors they would burn up. They are very wasteful and increase the owner electric bill. But the companies that manufacture these attic vent fans make them as cheap as possible to make the maximum profit and do not care about the consumers electric bill.
 
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