Consumer Homes.

Question:

You have gable vents.  Depending on their size, you could install a thermostatically controlled fan to vent air across the attic from the other side.  This is something the roofing guy doesn’t need to be involved with, just yourself and an electrician.  It never hurts to put more insulation in, but put it in the ceiling joists and not the roof joists  Feel your ceiling in the summer and you’ll know why your AC runs all the time. – Hide quoted text — Show quoted text ->Thank you to everyone with all the great information!  Especially >Peter – you gave me an option I didn’t even know existed: >A ridge vent performs the same function as an attic fan, but uses a simple >passive device and fundamental principals of physics.  The non-load bearing >ridge of your roof is removed and replaced with a vent covered with roofing >shingles.  This vent works in conjunction with your ADEQUATE eave vents to >allow natural convection (that is, hot air rising) to pull cooler air into >the attic. >After going outside and taking a look, I don’t think we have adequate >vents – considering, there are only two openings in the entire attic, >one at each end of the house.  The ridge vent sounds like our best >option. >I read your post to my husband and he agrees this is something we need >to discuss with a roofing professional who we have to hire anyway to >take a look at a leak which we detected during some recent heavy >rains. >I appreciate very much all the input! >Leigh >– >Consequences, shmonsequences, as long as I’m rich.  - D. Duck

Response:

>I can’t speak to an attic fan, but you are right on target with your >comments about a whole house fan.  We have one and LOVE it.  They work >great IF you live in an area where it cools off outside at night and >you can cool the house by bringing that outside air into the house >pushing the hot air out through the attic and outside. >You would NOT want to use one if you were using AC, and they’d be of >limited value if it doesn’t cool off at night.

And they do require a small amount of common sense… Running one (even on low) with the windows closed and you end up sucking vent air through all the burner vents (hot water, furnace, etc) and into the house.

Response:

Thank you to everyone with all the great information!  Especially Peter – you gave me an option I didn’t even know existed: >A ridge vent performs the same function as an attic fan, but uses a simple >passive device and fundamental principals of physics.  The non-load bearing >ridge of your roof is removed and replaced with a vent covered with roofing >shingles.  This vent works in conjunction with your ADEQUATE eave vents to >allow natural convection (that is, hot air rising) to pull cooler air into >the attic.

After going outside and taking a look, I don’t think we have adequate vents – considering, there are only two openings in the entire attic, one at each end of the house.  The ridge vent sounds like our best option. I read your post to my husband and he agrees this is something we need to discuss with a roofing professional who we have to hire anyway to take a look at a leak which we detected during some recent heavy rains. I appreciate very much all the input! Leigh — Consequences, shmonsequences, as long as I’m rich.  - D. Duck

Response:

> Whole house fans, on the other hand, seem to pull air from the house > through the roof – so wouldn’t that just pull air conditioning OUT of > the house?  A lot of people say they have reduced their need for A/C > with these, but I wonder if perhaps they don’t live in climates where > it’s 80 degrees at night!

I can’t speak to an attic fan, but you are right on target with your comments about a whole house fan.  We have one and LOVE it.  They work great IF you live in an area where it cools off outside at night and you can cool the house by bringing that outside air into the house pushing the hot air out through the attic and outside. You would NOT want to use one if you were using AC, and they’d be of limited value if it doesn’t cool off at night. —                                                 Brett K. Carver                                                 (707) 577-4344

Response:

I’ve checked the Google archives on the topic of attic and whole house fans, but I’m still confused.  Please forgive me if I ask a very tired set of questions, but I’m afraid I can’t figure out if we need an attic fan, a whole house fan or nothing at all.  Sorry for the bandwidth here, but I’m at a loss. We’re about to do some improvements to our house (our first home, so we are newbies at all of this).  One thing we want to accomplish is cooling off the attic of our split level house.  We live in Georgia where the summer days can be up to 100 degrees and extremely humid to boot.  If the door to the attic access is opened, a BLAST of heat will just about knock you over.  It’s reeeeally hot up there during sunny summer days.   Since sometimes our A/C runs 24 hours a day to make it bearable in the house, we thought perhaps keeping this space between the roof and the ceiling of the living space cooler would help our energy bills.  We will also be adding insulation to the attic since there is precious little up there at the moment. I’ve read in old posts that attic fans are a waste at best.  A quote from one article:  "Powered attic ventilators, already suspected of using more energy than they save, can also create excess moisture, structural problems, discomfort, and combustion safety problems for home occupants…" Doesn’t sound too good, but others swear by them and say they keep the attic cooler, thus reducing the temp in the living space below. Whole house fans, on the other hand, seem to pull air from the house through the roof – so wouldn’t that just pull air conditioning OUT of the house?  A lot of people say they have reduced their need for A/C with these, but I wonder if perhaps they don’t live in climates where it’s 80 degrees at night! So for a hot, humid climate, which would you recommend?  Just adding insulation and leaving the attic alone otherwise, an attic fan to pull air from one side to the other, or a whole house fan to pull air through? Thanks for any advice! Leigh — Consequences, shmonsequences, as long as I’m rich.  - D. Duck

Response:

Leigh – House Fans, Attic fans and Ridge Vents.  What do they do, and which do you need. A house fan, or whole house fan, is a large (30-36") box fan that sits on the ceiling of the second floor and pulls air from the house and expells it through the attic.  The fan is run with windows or doors opens, and performs two functions.  First, it replaces individual window fans that one would use to pull outside air into a room to provide a cooling breeze.  Second, it expells this air into the attic, and forces the really hot attic air out of the attic, essentially cooling off the attic at the same time.  If you’re running air conditioning (central or window) and run your attic fan, you’ll be pulling your expensive cool air out of the house and pushing in through the attic.  For a whole house fan to work correctly, you must have sufficient holes in your attic for the air to be pushed out of.  These holes are typically in the form of vents on the sides of your attic wall. An attic fan takes many various forms and is usually mounted on the side of your attic or on the roof and pulls air from your eave vents (the eaves are the overhang where your roof meets your walls) and pushes it through your gable vents (the gables are the horizontal wall section of your attic).  The purpose of the attic fan is to keep your attic relatively cool – they are typically temperature controlled and turn on at something like 130