Attic Fans - are they worthwhile?

[gfmucci]

The contractor who installed a dark shingle roof on my home suggested the installation of an attic fan for $285. It vents through the roof, pumps about 1200 cfm and supplements the convective air movement of the soffets and ridge vents. He said he sets the thermostat so it kicks on at 105 degrees and will lower the garage temperature by about 15 degrees.

So, does anyone have any experience to indicate whether these attic fans are worthwhile or not?

[ejp52]

I just had this installed about a month ago in my home and it makes a big difference in the temperature in the garage,it was well worth the price.
I have the same style home as you with the golf cart garage.
I also had vents installed on main garage door.

[chuckinca]

Why not start at 95 and lower the temp to 80 - 85?

[gfmucci]

Why not start at 95 and lower the temp to 80 - 85?


My answer if you are serious:* The manufacturer's default setting for the thermostat is 110.* The installer changes it to 105 because he feels it gets the garage temp down a couple more degrees.* Setting it much lower than that likely makes the fan run almost all the time without any signifcant temperature reduction in the garage. This assumes the uninsulated garage heats up to a temp higher than the ambient air. For example, my existing closed garage temp gets up to about 110 in the afternoons when its only 88 outside. Garage insulation and/or an attic fan will apparently help those who don't want to leave their garage door open a lot.

My answer if you are joking:* I prefer the temperature at 72 in the garage, so I think I'll lower the durn attic fan thermo to 87. (When it's 97 degrees outside)* ;) ;)

This is why when I think of not AC'ing the garage I remind myself that no matter how much (outside) air is circulating through the attic or through the garage, the garage will never be cooler than the outside air. I remind myself of the 97 degree afternoons.

[Sidney Lanier]

We had The Solar Guys install a solar attic fan on our house; there is no wiring to this type of fan, instead running whenever the sun hits the solar panel which is mounted on the outside casing of the fan. We have not had it long enough in TV to know how it works, but Ive had attic fans in every house I've owned and they do a great job moving the outside air through the attic. Even when it's hot outside, the stationary air in the attic would get much hotter if not for the fan sucking in the relatively cooler outside air, hot as it may be. I have no idea how our attic fan will affect the temperature in the garage; that'll be interesting to find out.

[chuckinca]

We have automatic attic fans installed at our summer home that are set at 90. They probably run all day in the summer but also probably keep the temperature down below 110 on most days which should keep the adjacent rooms a bit cooler.

[tankdvr1950]

Sidney.....what did they charge you for the solar fan and installation???

[JeanneBeannie]

I had one in my previous home and loved it, I used it all the time. :thumbup:
I think the price they quoted you is very reasonable. :)

[NJblue]

If it lowers the temperature of the garage by 15 degrees, it must also make a sizeable reduction in the cost to air condition the house.

When talking to one of the solar fan distributors, I asked him why should I pay so much more for a solar unit than a wired unit. He claimed that the cost to operate a wired unit was quite high and quoted me a figure (which I now forget) which would indicate that the solar unit would pay for itself in just a year or two. My gut tells me that his figures for operational costs for wired units were a bit exaggerated but I can't prove it.

One thing that I didn't like about the solar type that I was looking at was that it runs whenever the sun is shining (there was no thermostatic override). This means that in the winter when you may want the attic to be warmer to keep the house warm, you are still expelling the warm air all day long.

I will be looking into installing a wired unit when we get down there full time. Can anyone recommend someone who does this for a reasonable price?

[Barefoot]

We had The Solar Guys install a solar attic fan. Even when it's hot outside, the stationary air in the attic would get much hotter if not for the fan sucking in the relatively cooler outside air, hot as it may be. I have no idea how our attic fan will affect the temperature in the garage; that'll be interesting to find out.

This is probably a stupid question. But I'm a girl, so the answer isn't obvious to me. If you're not in TV during the summer months, why do you care how hot it gets in the attic or the garage?

We have a humidistat which means our air conditioning costs are peanuts per month. I'm just wondering why an attic fan is such a benefit.

[graciegirl]

Bare. We were thinking about having a humidistat installed and ran out of time. Did you do it yourself?? Sweetie thinks he can do it and probably can. He wired another outlet in the garage for a nifty pull out ironing board.

How much did it affect your bill?

We had low, low bills last summer by just setting the air conditioner on 83. I was shocked...and we did not use the air conditioner much at all from January to end of April when we left. They build these houses so nicely to get cross draft and the breeze is always blowing. I love to have the windows open. (But Helene is always sneezing.....:grumpy:(That is a sad avatar)

[chuckinca]

We will be storing stuff (99% my wife's) in the large attic over the garage - keeping it cooler, even when we aren't around, is a good thing.

[clyd709]

I would not be without Attic Fans here in the South. I had them in the Home I lived in The Villages and also have them in my home here in Georgia. I have never had the Solar Type just the Regular Electric ones and they ar great. It is great especially if you are going to store some things in the Attic. Mine are set to go on at 100degrees. I think the prices that are being quoted are very reasonable. :agree:

[MelZ]

I had "the solar guys" (they advertise here) install a solar attic fan on our house in December, so we will not know the true saving till the summer is over. They also installed a solar tube at the same time. They were very helpful and did a excellent job.

I went with solar because in our home up north I had a wired attic fan and had ongoing issues post warranty. The motor burnt out and created a short, I had to get an electrician to trouble shoot the problem. The installer had used the same line as a in house circuit, and the breaker kept tripping.

With Solar if the unit ever fails you can't effect you home wiring. I prefer the solar unit because their are less things that can go wrong in the future.

[BobKat1]

This very well may have changed since we looked at attic fans several years ago, but we learned that solar fans don't move as much air as electric. The solar motors (at that time) weren't as strong as electric. We liked the obvious benefits of the solar fans though. I'm not sure what the requirements are in FL, but maybe something to consider.

[Barefoot]

Bare. We were thinking about having a humidistat installed and ran out of time. Did you do it yourself?? Sweetie thinks he can do it and probably can. He wired another outlet in the garage for a nifty pull out ironing board. How much did it affect your bill?

GG ... I wanted Munn's Air Conditioning Service to check out our air conditioning unit because it was four years old. And it wasn't a lot to have them also install the humidistat. (Fireboy wanted to install it; he said it would be easy peasy to install).

We saved bundles of money on our air conditioning last summer .. just cost a few dollars a month to run. (I am vague on details, I haven't unpacked my Florida stuff since we returned to Canada two weeks ago). I think I'm still in denial that I'm back in Canada.

Whoops .. sorry Topicop :police: .. just realized this thread is about attic fans and not humidistats. Me bad.

[REDCART]

The Solar Guys installed a solar fan for us in early 2005. Last year the motor bearings went out and it was howling like a wounded animal. Solar Guys honored the Mfr 5 year warranty and replaced the fan motor quickly and with no charge. Normally the solar fan is very quiet and on occasion I have climbed up on the roof to see if it's really working. The solar fans may not move as much air as a wired fan but it does the job and you can feel the difference in the attic when it's running.

[billethkid]

high you set the thermostat to keep the AC from running.
The humidity does collect the higher the temp is set.
We set ours at 80 which runs minimally allowing some dehumidification on the really hot days.

BTK

[Peazoup]

Another consideration regarding solar attic fans is that having a fan installed increases the life of your roof according to the Solar Guys who installed mine. Also, along the same lines, ************************ installed my humidistat and I saved about $100/month on the a/c bill when the house was empty during the summer months last year.
Another fabulous job done by our "Handie".

[TrudyM]

If it lowers humidity I would think that would effect the feels like temp.
Could a thermostat shut off be wired between the panel and the fan or better yet a switch over to feed into house lines for gain. Not an electrical engineer just thinkin outside the box.