In my last two houses, I've installed wwaf and found them very helpful keeping a cool house in most weather.    Missing one in the new house but I see the technology has changed.   Both others were a 24 or 30" fan, mounted on the top side of the ceiling and just pull air through the house and out the attic vents.

 

  

They still make them, but make two new styles.

 

First one sits in a flexible tube and is suspended from the attic rafters.

 

Second new type is more like an insulated clamshell that opens when the fan runs and closes when it doesn't.

Any experience with these?  Costs vary a lot.

the one in the flex performs poorly...

the insulated on works great and you'll value the insulation come winter time...

the second on is a better value IMO...

My daughter just had one installed in her attic. 36" and really is a HUGE help. I assume it has insulated louvers too. Building code requires a foot or more of insulation. No idea what the cost was, but they do not use their air conditioner much at all.

 The one on the flex looks much smaller, judging from the rafter space. I can see that one swinging around too

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I have had two houses with fans like the 1st picture and they worked great. All I have now is the roof fan attached. What I do when I get up 5:30am -5:00am and open all the windows and use box fans set in the windows on high and when I get the house down to as low as I can get it or to around 60, I turn the fans off and close the windows. It was 97 here today. I set the air at 72 and it was 6pm when the air came on.

Preston

I like the idea behind the clam shell type especially in cold climates.  Either way I bet they are a lot quieter than the old style.

How about that. For various reasons I haven't had an attic fan since we left Kansas (and I really liked the one we had there), I had no idea they had changed that much.

We had one and it worked great until A/C became common.  Also the AC helps maintian a consistent humidity.  It is also quieter.  However be advised that these things move a lot of air and you need to make sure your soffet vents are capable of the increased flow.  In the house we installed them my dad had to add soffet vents to keep the motor from stalling.  They are also quite noisy if i recall correctly.   Install in an interior hallway to vent the whole house.

Be sure to crack a window in the basement or lowest level to.  This creates a draft of colder air and is also required to keep the motor cool.  The one with the preinsulated louvers is a great improvement.  We as part of fall prep would seal up the fan with insulation over it.

 

 

Ours is a 36" one. Sounds like a B-29. But it moves gobs of air. Pulls in night air and, the residual coolness means less AC use. It also cools the attic, which helps, too. Usually, 30 minutes of run time is enough.

In the winter, I gotta crawl up there and put an insulated panel over it. Didn't used to be a chore.

Edited August 8, 20187 yr by Gene Howe

I put one in our home in the mid-1980s, then we moved in 1995 and I put one in there, too.   Both were two stories and went in the upstairs hall and were of the original type.   Now we have a ranch since 2016 and the logical place is in the hall right off the great room.   We do have about 8 roof vents and 2 @  4 sq ft gable vents, so I'm not too worried about that.    I used the 70-70 rule -- overnight temp above 70 degrees or dew point over 70 then the a/c comes on.   We'd typically run a/c a few weeks a year, about a week at a time.   I'd climb up to the attic in the fall and put on insulation and again in the spring and take it off.   I'd like to get one installed in this house, but the offerings and options have changed.   The first type runs about $250-300  and the third type is pushing $1000.

I purchased a home which had one already installed many years ago.  It was like a wind tunnel when it was turned on.  The curtains would blow straight out in the room and it would suck in dust/dirt.  My wife did not want it turned on.  Danl

37 minutes ago, Danl said:

I purchased a home which had one already installed many years ago.  It was like a wind tunnel when it was turned on.  The curtains would blow straight out in the room and it would suck in dust/dirt.  My wife did not want it turned on.  Danl

shoulda redid the pulley ratio and slowed it way down...

13 hours ago, kmealy said:

 I'd like to get one installed in this house, but the offerings and options have changed.   The first type runs about $250-300  and the third type is pushing $1000.

But that third type sure looks like a much more convenient option. I still remember putting the "winter seal" on every year and it was a royal PITA. plus which I'm sure it didn't seal all that well.