attic ventillation, keeping it cool

[PRND3L]

Originally Posted By: mechtech2
Another option is a fan in the access to the attic.
this pulls air from the house, and forces it through the vents.
It makes a big difference in attic temps.
And there is no need to cut the roof .



My attic access is in the garage ceiling. Using this option, which way would I point the fan to blow? Into the attic or into the garage?

 

[Schmoe]

Into the attic but be careful not to totally blast the attic. You don't want to over pressurize the attic as some of the hot air will forced back into the house.

 

[PRND3L]

ty Schmoe.

 

[mechtech2]

Unless you want your garage kept really hot, you should blow into the attic and out the side vents.
The garage is a pretty good place for a fan like this - you can have the house AC on and still purge the attic of really hot air.

 

[Steve S]

Originally Posted By: dkryan
Originally Posted By: Steve S
I installed ridge vents and increased the size of the soffit vents . Then installed radient barrier stapled to the underside of the roof , the total job made a real big difference.


You increased the size of the EXISTING soffit vents, as opposed to ADDING additional vents?

Did you install the radient barrier yourself, Steve, or have someone do it for you? Regardless, what brand (type) did you have installed?

I increased the soffet vents, added 1 vent on each side of the house and doubled their size. Then added ridge vents in addition to the scoop looking vents that were there already. The amount of hot air comming out of the area I cut on the ridge of the roof was shocking. Then I stapled up the radient barrier under the roof myself. I do not remember the brand name but I bought it off the internet from [I am almost positive cause it was 3 or 4 years ago] Farmtech equine supply . There is a whole lot of info on the web about installation of radient barriers. I bought a foil with some kind of membrain center for tear resistance then foil.

 

[bigmike]

Down here, especially in central Florida, the older homes have these "whole house fans" similar to what mechtech is talking about. Typically, in a hallway, there is a very large (4 feet or longer by 2-3 feet wide) fan that blows air into the attic. Never turn one on w/o an opening to the outside!

The intent was for people to be able to instantly cool down their house and attic. This was mainly before A/C came along. The fans work fast and my grandparents only ran theirs for a few minutes at a time then shut it off.

I have off-ridge vents with soffits. Someone that owned the house before me put in an attic fan in the roof. Now there is a bucket under it, but I've never noticed it with water - probably just a precaution. Inspector said it looks like nobody ever used it. When I re-roof the house, I'll have it removed.

If you have a gable end, it might be a good place to put in a solar fan or temp. controlled like many are suggesting. I wouldn't put it in the roof though.

You guys up North have alot of extra problems and considerations than I do!

 

[VNTS]

I have ridge vents and soffit vents. House built in 1999 Colonial two story.

Also have a whole house fan in 2nd floor hallway. When temps drop at night in summer, simply turn on and within 15 minutes can drop the inside temp to outside temp.


Per the attic, I would think the addition of the attic fan solar powered would be a good idea only drawback would be another penetration in the roof and possible leak, especially in the winter. I would look into a gable end mounted fan for that reason.

Per the radiant barriers, I see they have the material at Cheapo Depot but never considered using it. Assume you stapple to the rafters.

LastlyI have a drop down stairway into the attic. I wonder how many people have blown in insualtion covering up the soffit vents, hence they dont get the drafting up the rafters.