Opinion of Attic and Whole House Fans

[kidicarus13]

Installed a high-efficiency A/C 2 years ago but now considering adding an attic fan to cut down on Xcel bills and allow my A/C to last longer. Thoughts or experiences?

We have high ceilings and on hot summer days it takes hours for the AC to cool the bedrooms on the second floor down to sleeping temperature.

[ray1970]

We have high ceilings and on hot summer days it takes hours for the AC to cool the bedrooms on the second floor down to sleeping temperature.

Yeah, most AC systems aren?t going to take a house that?s hot and cool it down very quickly. I make sure I kick mine on as soon as the weather starts getting warm and just leave it on until winter. It?s easier for the system to maintain the temperature in the house by cycling as necessary rather than running for hours on end trying to make drastic changes.

Anyhow, I am also thinking about some sort of fan system (mostly for spring and fall) so I?ll be following along.

[electronman1729]

I did a whole house fan last year with Quite Cool Love it. It was only $1800 or so. I open the windows after the temp cools off and run the fan an hour before going to bed.

[kidicarus13]

I did a whole house fan last year with Quite Cool Love it. It was only $1800 or so. I open the windows after the temp cools off and run the fan an hour before going to bed.

I wonder if I proceed if it's worth getting multiple quotes or will they all come in within $300?

[colorider]

They work great when the outdoor air is cool. Whatever it is outside, it will be inside, it will be inside. So when we have those summer nights where it's super warm at night, ya won't be cooling off so much. Good thing is that those kind of nights don't hang around much. They work really really well when the outside temps are to your liking.

[Ramsker]

We've had a whole house fan for about 12 years . . . and we also have central air. The whole house fan is glorious on the nights that get cool, especially when you get later into the summer and fall. It's flat-out amazing how fast and efficiently it can cool the entire house down. So we use it in conjunction with the A/C. A/C keeps the house cool during the day and then if it cools down significantly at night, we crank up the whole house fan and drop the temp down further for bedtime.

On those nights where it's not as cool, it's not as beneficial (or if it's raining hard and you can't leave the windows open or want all that humidity brought in). But even on those nights, you can cut the heat down a good chunk pretty fast especially on the second floor.

[gnihcraes]

Colorado home cooling. Great installer. Specialist in whole house fans.

In Lakewood. Give them a ring.

[cstone]

Do you have ceiling fans? Start with the bedrooms and then the larger rooms where access to fish the wiring isn't too difficult.

Most of the fifteen years we lived in CO, we ran the AC for two weeks each summer. Most of the time we just worked the windows and blinds. Get up in the morning and close the windows and blinds while the house is still cool. The upstairs rooms would get warm afternoon, but we didn't use those rooms during the day. As the sun went down around 7PM or so, the blinds and windows would get opened. By 10PM or so, the house would begin cooling off. Ceiling fans really helped.

Low humidity is a real blessing in many ways out west.

[brutal]

Do you have ceiling fans? Start with the bedrooms and then the larger rooms where access to fish the wiring isn't too difficult.

Most of the fifteen years we lived in CO, we ran the AC for two weeks each summer. Most of the time we just worked the windows and blinds. Get up in the morning and close the windows and blinds while the house is still cool. The upstairs rooms would get warm afternoon, but we didn't use those rooms during the day. As the sun went down around 7PM or so, the blinds and windows would get opened. By 10PM or so, the house would begin cooling off. Ceiling fans really helped.

Low humidity is a real blessing in many ways out west.

We did that routine with just a whole house fan and some localized fans here since 1995. 2-story colonial of mid grade 2x4 construction. In 2003 I became PT WFH (with limited travel) and installed a window AC in my "office," a.k.a. one of the upstairs bedrooms. Older home just isn't setup for a ground floor office/study and we never built out the 2/3 basement. Did not expect to still be here, but here we are. in 2009 I became FT WFH (with more travel.)

Finally installed a whole new HVAC system the spring of 2019 so I only run the house fan occasionally when I haven't kept the house cool enough and need to drop the temp quickly. Since we have continuously variable fan setups in the condenser and furnace/evap, it cuts down on elec use over the house fan so I don't do it once the house has cooled. We still try to keep the southern exposure closed up during the day, but it's not so important now.

If you need to evacuate a bunch of hot air, the house fan certainly helps.

[Martinjmpr]

When we bought our new-to-us house in 2017 it had a whole house fan but no AC. The whole house fan works very well to keep air moving through the house and to cool it down in the mornings and in the evenings. During the heat of the day, the whole house fan does nothing. We finally did install central AC last year and it was very nice, and not nearly as expensive as we'd feared it might be.

Overall we're happy with the AC but it's definitely nice to have the attic fan for those times when AC isn't necessary. It hasn't gotten hot enough for us to even turn the AC on yet this year but we've run the attic fan several times, usually we switch it on after about 6:00 and with the porch sliding glass door open and the front door open (both screened) it is amazing how quickly the house cools down.

That's actually one of the best things about the house fan - how quickly it works. If the house is hot and the air outside is cool, we switch on the attic fan and in minutes the house is several degrees cooler. The AC doesn't work nearly that fast.

I guess what I'm saying is that having both options makes a lot of sense here in CO. AC for those brutally hot August mid-days and the house fan for the "shoulder seasons" of Spring and Fall when it's hot but not hot enough to turn on the AC.

We're still tweaking our methods but what we seem to have arrived at is that if one of us is home during the day and we know it's going to be hot, we'll switch the AC off, open the doors and run the house fan until about 10:00, when it really starts warming up. Then we'll close up everything and turn the AC on.