You mean a fan which just moves air through the house, using the A/C and heating system? If so, yes, we have that. It's nice. If the house is stuffy, I can open the front door or a window so fresh air can come in through the intake and circulate around the house. This is helpful sometimes in early evening on a warm day. Sometimes we can use the fan a bit to avoid using the A/C.

Are you replacing heating and A/C, or what are you getting? I think there is a heating and A/C Forum here, maybe.

If you mean an attic fan, I grew up with one in our house in Louisiana. I absolutely loved it during the perfect time of year. After it gets too hot in the summer months in Louisiana it didn't work near as well. But this time of year it's fantastic especially at night. However if you have a lot of allergies it might not be good for you.
I would like to have one here at times but with my allergies these days probably not a good idea.

We have a whole house fan in our home. It was here when we moved into this house. It really does a nice job of cooling the house with outside cooler air. We use it a lot in the late spring and beginning of summer and in the fall too when we don't want to use the air conditioner, We live in Georgia. We do not dislike it at all. We did replace it a few years ago. It is loud but that lulls you to sleep.
Mary

This is very similar to the one we had. It has a cover with the lovered vents that automatically open when it's turned on.

Here is a link that might be useful: Attic /whole house fan

We had attic fans installed about 20 years ago.....what a difference it made on the second floor in the summer! Before we had them you could literally feel the temp increase as you climbed the stairs..it was easily 10-15 degrees hotter up there. I think they were cheapies because they are a little noisier than I'd like..we just talked about replacing them with better quality and hopefully quieter.

I also got an attic exhaust fan a couple years ago. It's like a miracle. Even with the AC on before I got the fan, the upstairs got uncomfortably warm. I would be hot at night and sometimes slept downstairs. Now the fan goes on, cools the attic and the upstairs stay comfortable. I just love it.

If you mean a fan that pulls air through the whole house by sucking it in through the open doors and windows, they can be great too. My friend had one and I was impressed how it cooled the house, provided the outside air was cool. It wasn't so great when it was hot and humid.

We have one upstairs that blows the hot air out and then pulls cool air in all the open windows. It's great for Spring and Fall but we do need AC during the hot and humid summers. We love it though!
Joann

Our whole house fan brings in outside air and exits the inside air. Ours goes on 3 times a day for half an hour each time. In the summer I change it to run several hours at night to bring in cooler air. All the outside air is filtered through the furnace and goes to each room through the furnace ducts. A fan in the laundry room exits the air. So it is actually two systems that interact.

With the evolution of what's called Building Science (yes, it's a real discipline) in the last 20 years, poking extra holes through the "envelope" (the walls/ceilings/floors of the interior) to the exterior has fallen on disfavor. The trend is to do the opposite - seal the snot out of every possible place for air movement between out and in, then manage the air movement deliberately.

Translation - making an opening and blowing interior air into the attic isn't a good idea. For those that have blown in insulation or limited air vents, you don't want to know what the 1500 or 2000 cfm of air the fan blows up there is doing. Like swamp coolers in the west, these fans were useful before AC became widely available and affordable. Today, they're dinosaurs that work against what you want to accomplish most of the time.

Many existing attic fan installations have only the louvers between inside and the attic, and they leak like mad. They're a source of hot air into the house in the summer time and cold air to come in during the winter. It's a good idea to remove the louvers and drywall the hole shut.

Open your windows and consider installing opening skylights to help you use the breeze and rising hot air to do the job.

Interesting responses.

Hubs has decided that he wants to get a whole house fan. The kind where you open the windows and turn on the fan which will suck in cool air from outside, and it puts the hot air from inside the house into the attic space. I did tell him that if we ended up installing one, we'd also have to install an attic fan to blow the hot air out of the attic (to the outside).

Raven, my Hubs does have allergies. How does a whole house/attic fan adversely affect allergies?

One plus for a whole house fan is removing hot attic air as the day cools. One need not use the fan 24/7 in all seasons, but it is very useful in some situations.
I recall a previous house with central air,and unfortunately no trees shading the house. At 4PM you could put your hand on the ceiling and it would feel warm.
A fan that helps unload all of that warm air and brings in the cooler air can save significant electricity costs.

Here is a link that might be useful: Electricity costs

Lindsey...if your DH has allergies are you sure you want to open the windows and invite all the dust and pollen in to collect on your furniture? Could make his allergies worse. I have always heard that people with allergies should never open their windows during whatever season bothers them most and should invest instead in good filters.

You do not need to open any windows with attic fans...they just keep the attic temp down by moving the air and as a result the 2nd floor does not get nearly as hot. Ceiling fans in all the bedrooms helps alot as well....we use ceiling fans, AC and attic fans in the summer.

I wanted one, even bought one but was told we couldn't have it installed because we don't have an attic...Our bedroom ceiling is the roof (very little in between)....Personally, I don't think they know what they're talking about and really think it can be done...But, then I'm female and what do we know.....
Everyone I know that has 1 really, really like it......
(I'm still working on it)

we invested in good window box fans and get about the same amount of relief...we don't have all-house ac, just 2 window units...

Ours was the kind that you open the windows and it pulls in the cool air from outside into the house and out through the attic. Even on warmer days the strong movement of the air flow makes it feel cooler.

As for allergies, you are sucking in everything from outside into your house including any pollen or dust. I used to get very stuffy at night when we ran the fan.

They have made advances in them and many have very secure insulation covering the closed fan. It is essential that you have a house that breathes and has a very good regular exchange of air movement from ground to attic. If you don't you run the risk of developing mold.
The kind of fan that just vents the air from the attic to outside the house is a completely different thing, but they are very good for helping to lower the heat buildup in the attic. Especially if you have your heat and AC etc up in the attic. It gets extremely hot up there in the summer and the heat can certainly contribute to failure of some parts. We have lots of ventilation in our attic but here in the extreme heat of a Texas summer you can't stand to be up there for more than a few minutes.

Houses develop mold from having too high interior relative humidity. In muggy areas (East Coast and South), that comes from leaky houses/HVAC ducts and/or oversized AC systems that don't run long enough to dehumidify. People make that situation worse by keeping the fan running, that causes interior air to reabsorb humidity that was removed by the AC coil. Some houses need hard wired/plumbed dehumidifiers in addition to AC systems to provide comfort on hot yucky days.

The kind of fans that blow air out from the attic are looked at unfavorably these days, because they cause a negative pressure area that draws air in to the attic from the house, through the ceiling and wall openings. The air drawn out of the house is replaced by outside air into the leaky/porous house, making the interior more humid. Passive atttic ventilation, with gable vents or ridge and soffit vents, is what's recommended.

Honestly, a lot of the old time approaches have been discredited. The problem sources are much better understood today. The oversized AC problem is a big one - HVAC contractors always oversell size (more $$$ in the equipment sale) and the consequence is too humid interiors.

We have an attic fan and absolutely love it. I can open a few windows just a few inches around the house and turn on the attic fan and pull cool morning air into the house and then when it starts to warm up outside I turn off the attic fan and close all those windows. I usually don't have to turn the air conditioning on until three or four in the afternoon when I do that. Then by the time we go to bed it's usually cooled off enough that I can turn the air off and we can just sleep with an open bedroom window. It saves us a lot of money on our electric bill. And I like having the fresh air for most of the day as opposed to air conditioning. I'm not crazy about the noise that it makes but after a while you get used to it.

In the wintertime, I tack up plastic over the louvers to stop any of our warm air from leaking out up into the attic.

I can pretty much copy Flamingo's response. The attic fan keeps me from running the AC for weeks and weeks. Sometimes when the temps are rising we'll sleep all night with it on.. I sleep really well with it on even though it is noisy. We can't have it on during pollen season.. not because we have allergies.. just that I don't want all the pollen inside my house. :)

I don't think I'd have a house that didn't have one.

JoaniePoanie said You do not need to open any windows with attic fans Not sure what type of fan she has, but we definitely need to open windows with ours.

Hubs is pretty much set on getting the whole house fan. He does have allergies, so that concerns me, and our house tends to get very dusty even with the windows closed, so goodness knows what will happen with the windows open for the fan...

The house was built with a ceiling fan in the family room and in the master bedroom, and in the summer they're both used a lot. And we do have central air conditioning, but we don't want to run it 24/7.

If it weren't for the fact that we have a cat that Hubs pampers even more than he pampers me (and that's a LOT), and the fact that we have so much wine in the house that will get ruined if it gets too hot, I don't think he'd be considering a fan. The large temperature & humidity controlled wine cellar only holds about 495 bottles (including a couple dozen magnums that are in there), and the little one in the dining room holds 50 bottles. Both are full, and we have more than 400 bottles that we can't put into either of the cellars for lack of room. Neither one of us wants to ruin any wine.

I would like one.

When I installed an attic fan in in my house, I made sure it was placed as far away from the bedrooms. Otherwise the noise makes it tough for a light sleeper. I am a person who needs fresh air.