Automatic Attic fans

[TroyBoy30]

Was looking into installing a couple of auto attic fans, to suck the hot air outa the attic of course! My ac guy tells me they would be very easy to install and would allow my upstairs ac unit to run less when it gets super hot. Anyone know anyone that can do the installation? I couldn't decide whether to call an electrician or a roofing guy or what!

[wallypiper]

They don't have to be installed in the roof. They can go in the gable. But if you have good insulation in the ceiling, I don't think it's going to make a huge difference. Do you have ridge vents? Read this (http://www.askthebuilder.com/236_Powered_Attic_Fans_-_Attic_Insulation_Facts.shtml)

[TroyBoy30]

yea I do have ridge vents. That article is a totally contradiction to everything I have been told by every ac guy I have asked

[steve c]

See the studies from several .edu's. They use more power than they save. Insulate like a mo-fo, and use passive vents (gables, ridge vents, turbines.) Solar powered vents are fairly new and there is not much research on them yet.

- Steve

[Dbl k]

I had both a roofer and an insurance adjuster tell me that the fans were a waste and to get a ridge vent when I get my new roof.

[TroyBoy30]

yea I have all that stuff already. simply trying to take more load off the upstairs ac. looks like I'll go with window tint and see what that does

[jkhonea]

Ridge vents are much better. Along with the energy they draw, ridge vents tend to stop working correctly. A lot. Either the motor goes bad or the thermostatic controller.

[jkhonea]

Do you know if you're ridge vent was installed correctly? Not uncommon for several things to go wrong with it. One, getting felted over and not cut open again in a reroof situation. Two, the osb not being cut back to the appropriate sizes to let the air escape the roof. Those are the primaries. And both are very common mistakes.

[Bryce]

Ridge vents are much better. Along with the energy they draw, ridge vents tend to stop working correctly. A lot. Either the motor goes bad or the thermostatic controller.

Yep.. our house had powered vents when it was built and I replaced motors on them every 5 years or so until we got a new roof and did regular ridge vents instead. didn't really notice anything since my attic is well insulated, but at least I won't waste money on new motors anymore.

[TroyBoy30]

Do you know if you're ridge vent was installed correctly? Not uncommon for several things to go wrong with it. One, getting felted over and not cut open again in a reroof situation. Two, the osb not being cut back to the appropriate sizes to let the air escape the roof. Those are the primaries. And both are very common mistakes.

I assume they are. will get someone to check I guess

[steve c]

On a previous home, the ridge vent was installed, but there was never any opening cut in the sheathing. Dumb f@cks!!!

s

[jkhonea]

On a previous home, the ridge vent was installed, but there was never any opening cut in the sheathing. Dumb f@cks!!!

s

That's what I was talking about. :up:

[jkhonea]

I assume they are. will get someone to check I guess

Give that a shot first. Will probably have to be done from the attic. Can't remember if its possible to check without actually getting all the way up to it. Well, you can see if the osb is cut back from that far, but if it looks like that is, really would need to get all the way up and check to see if the felt is cut back properly and not just covering the ridge, blocking the vent.

[Woodk61000]

I saw some at Home depot that were the solar powered gable vents. Make sure you get the ones made here and not China. Ive heard (from a builder) that some of their parts are made out of bamboo.

[TroyBoy30]

Give that a shot first. Will probably have to be done from the attic. Can't remember if its possible to check without actually getting all the way up to it. Well, you can see if the osb is cut back from that far, but if it looks like that is, really would need to get all the way up and check to see if the felt is cut back properly and not just covering the ridge, blocking the vent.

so anyone know a good roofing company then?

[Slurppie]

so anyone know a good roofing company then?

We used this company (http://www.atlantaroofingspecialists.com/) to replace our roof after the big hail storm a couple of years back.

[signguy]

so anyone know a good roofing company then?

I have a few for you... call me at the office....

[Mongo]

Our old house had the powered fans, needed a new roof and had them pull out the fans and put in a good ridge vent setup - noticed a HUGE difference the next summer.

[Bill3508]

I installed a powered fan two years ago at hour house. It made a big difference in attic temp and the ability to cool the house down. Normally during the summer or really any hot day when the temp was above 85 degrees and sunny you could not go in the attic at all without nearly suffocating. With the powered fan it is much cooler and you can easily work up there if you need to.

Our house had the standard 4 gable vents and it really wasn't enough. Ridge vents would have been better on the house from the beginning. I think the fan and install was around $250.

[JoeDirte]

I'm installing a whole house fan in my house this year. Open the doors downstairs and hit the switch, it will pull all the cool air from downstairs and force the hot air on the second floor and in the attic out through the roof vents. Takes about 45 - 60 seconds to clear all the hot air out.

[wallypiper]

Some energy/hvac truth from somebody that makes part of his living designing and supplying hvac systems for industrial applications.

If you have air conditioning, running a whole house fan may or may not save you money, depending on the ambient air conditions. When air passes through the cold cooling coil of your air conditioner, two things happen to it. It loses moisture, which condenses from vapor (humidity) in the air to a liquid on the surfaces of the coil. It loses heat, which also transfers to the surfaces of the coil.

The work done by your air conditioner consists of those two changes - removing moisture and removing heat. Removing moisture is much more work than removing heat and work = $$$. At this time of year, the outside conditions are very good at night, low moisture, cool air, great time to run a fan. Later in the spring, when the amount of moisture in the air is higher, not so much. Even though the air may be cool at night, it's wet. When you run a fan and fill your house with that air, it feels good at that point but the next day when the sun comes up and the house starts getting hot, the AC will come on and it will work much harder to remove all that moisture than it would to just remove the heat.

How can you know when it's good and when it's not? Dew point. Most of the weather reports include it, although you sometimes have to dig a little to find it. If the dew point is above about 55 degrees, leave the outside air outside.

[BadAssRX-7]

troy in a house my x and i had we had a "bonus" room over the 2 car attached garage. ther was a attic acc. door going from the bonus roon into the attic and MAN did it really kill that room. it was cold in the winter and hotter than the sun in the summer.... even with a window unit the room was hot. We insulated the wall that was joining the attic 2x and sealed the door up and this helped some. then we installed mirrored tint in the single windows at each end. THIS made a HUGE diffrence i guess due to the reflecting of the heat/light. and we also added a small fan. the room had walls about 3 ft tall and then the roof angled onto it so getting a fan that would fit was work all by itself but we found a 6 bladed 24" fan at lowes i think. that little bitch could move some air and that with the tint and window unit solved the heat issue. I know this is not your issue but was my 2 cents.... get good tint

[vtwinsports]

I had a similar situation in June.

My garage and kitchen were getting very warm during the day and because of the shared wall, were heating up the living room space quickly. This would cause the a/c to come on early in the day. Since the garage attic had no insulation and yet shared the wall with the kitchen and partly the living room, I decided to insulate the garage ceiling and add some more insulation to the kitchen ceiling.

I installed some insulation over the garage ceiling (they left it bare when the house was built) and then I added a gable vent fan over the garage myself. My main roof has 4 turtles in the back (which are on the west/sun side) and 2 other gable vents (on the north and south ends of the house.) I also opened up the area between the garage attic and house attic. They had a small crawl-through hole on the attic floor between the 2 spaces, which did not allow for much cross circulation/ventilation. I removed a lot of the fiberboard between the 2 attic spaces. I did this over the course of a couple weeks.

The results are that my a/c does not come on as early (even set at a cooler inside temperature) and the garage and kitchen remain cooler throughout the entire day. My a/c runs approximately 1/4 to 1/3 fewer hours over the course of the entire day than before (depending on which temperature I set the thermostat.)

Total cost of the insulation was approx. $110 (2 batts) The gable fan was approx $80. Wiring was approx. $10. Total cost was approx. $200. First month savings-and not even the entire month (Jun 09 vs Jun 10 according to Walton EMC) was $46. So I should recoup the cost in approx 6 months and reap continuous savings afterwards. Also, the insulation qualifies for the $1500 energy tax credit.

PS-I initially purchased the solar powered fan, however, after I went through the numbers and realized that it was not going to be powerful enough, I returned it and got an AC powered fan. The AC powered fan does cost energy, however, I see that it provides more energy savings than it costs to run. Your mileage may vary. FYI, the AC powered fan cost $80 and the solar powered fan cost $225.

[Back Marker]

after my roof was redone from hail damage, it was still getting extremely hot even with ridge vents. so i installed a cheap gable vent from amazon (prime customer). it was easy to install. i simply wired an old 3 wire extension cord to it's box and plugged it into the outlet. they should all come with a thermostat. i set mine to turn on at 100 degrees.

before, i had a problem with the attic ac not cooling the 2nd floor. now the 2nd floor is properly cooled. most mistakes made is that homeowners use too powerful a fan and sucks cool air from inside the house. there should be proper ventilation in the attic and make sure it's not sucking air through the ridge vents. their are vents all along the bottom of where the roof meets the sides of the house.

http://i181.photobucket.com/albums/x154/back_marker/renovation/gable-vent.jpg

-a|ex

[Mongo]

If you have open gables the ridge vents won't work. If you have a fan the ridge vents won't work. You need ridge vents with the only openings being in the soffet so air will flow.

[impalanar]

If you have open gables the ridge vents won't work. If you have a fan the ridge vents won't work. You need ridge vents with the only openings being in the soffet so air will flow.

I have ridge vents and soffets only and my attic gets up to about 140 during the day. I have my main AC unit off during the summer because it cannot keep up until the attic temp drops to <110 or so.

[Mongo]

Might want to make sure the soffets aren't covered up or something. Shouldn't be that hot if it's working right.

[DICKIEDOO]

I had a power fan installed in the attic this past winter and our power bills are down roughly 25% versus last summer and it's been great. I have a smaller home and I wouldn't do it any different. Go with a power fan. Ridge vents just didn't cut it with our house.

[TroyBoy30]

looks like I need to call in a company to check the vents and give me some suggestions