Whole house Fans.

[mscher]

I had read a newspaper home repair column, that says whole house fans are a great lower cost alternative, to air conditioning and do a good job cooling.

This is where a large fan is installed either in the ceiling of the highest floor, or into the roof istelf.

The fan is supposed to draw up the hot and then cooler air, from the lower levels, venting through the roof, where a lot of the summer heat stays.

Anyone use a setup similar?

they are talking about a 25% increase in co-op electrical rates in the near future.

Marty

 

[QC]

Re: Whole house Fans.

My mom installed one of these in the house I grew up in. Worked very well as this house had a basement (rare in CA) which was the source of much cooler air. It was in the top floor's ceiling and had slats that closed or opened by the flow alone depending on fan speed. Fan speed was controlled by a simple dimmer type switch rheostat thing. There were also a couple of turbine type deals installed in the roof to help get the extra air in the attic out. I swore/swear by the thing although I have never seen another one here. We have relatively mild summers and this eliminated the need for AC period. Enough to remain comfortable for all but 5 - 10 days a year.

 

[Tacklewasher]

Re: Whole house Fans.

Buddy has one and it seems to work for him. He's in the Vancouver area so summers are not incredibly hot. Might think about it for warm days but I'll keep my A/C for the 100+ days.

Buddy says you have to be careful to have windows open or it will pull enough air down the furnace/water heater exhaust to blow out the pilot lights.

 

[240sx4u]

Re: Whole house Fans.

My folks had one in each house I grew up in. They are especially awesome when its nice outside but calm. House gets warm inside, and the outside is cool. Draws that air right in.

I have been considering putting one in my garage too.

If you have space, do it. You have to have adequate roof ventilation to take maximum advantages. I suspect most soffits are vented nowadays.

 

[Hoss the Hermit]

Re: Whole house Fans.

Gotta admit, I'm a fan of whole houses. Spent some time in partial houses, half-way houses, and a little in a big house, and all in all, like the whole house best. Let's have a poll

 

[JoeCrow]

Re: Whole house Fans.

They're great for saving energy by reducing cooling costs
But if you're in a relatively hot/humid area you'll still need A/C
There's no substitute for A/C, it's just a helper

 

[mthieme]

Re: Whole house Fans.

Mom has a 36" unit in her house. It makes one heckuva difference. This is relatively cheap and easy thing to do that will make a huge difference.

 

[Xcusme]

Re: Whole house Fans.

I've installed 2 of them and they work a treat. No need to cut ceiling joists, just head them off.

 

[ebry710]

Re: Whole house Fans.

This is where a large fan is installed either in the ceiling of the highest floor, or into the roof itself.

The fan is supposed to draw up the hot and then cooler air, from the lower levels, venting through the roof, where a lot of the summer heat stays.
they are talking about a 25% increase in co-op electrical rates in the near future.Marty

If the outside air is cooler then the inside air, they cannot be beat. You have to open windows in hot rooms and the air is suck from the outside and transferred through the house, to the fan, through the attic and to the attic vent. All areas benefit.

Even though they are usually louvered, in the winter time you will want to insulate it sealed.

They are also great if you have to work in the attic.

I do not know about saving money using them, because you are using electricity for something only this unit can do. For comfort, when you are trying to cool the house to outside temperature and unsaturate the attic, there is nothing like them.

I have never seen them put through the roof though, only through the ceiling into the attic.

 

[DJ]

Re: Whole house Fans.

My folks have one in their lake house in AL.

It vents through the gable end vent. It's about 30" in diameter. It pulls house air into the attic through a closeable vent in the ceiling.

It works great in all but the hottest most humid months of the year. As stated, as long as utside air is the temp. you desire.

Here in AZ, we use a window fan, blowing out, to do the same thing. It makes a nice draw through any open window-door.

 

[i386]

Re: Whole house Fans.

I use ours to suck in some cool night air sometimes or to get rid of bad kitchen smells. It's humid where I live so we don't run it for more than 10-15 mins. If we run it a lot we end up with mildewed belts and shoes. I believe it also caused a terrible warp in one of my guitar necks once.

Use it sparingly when it's humid, otherwise they're nice to have.

 

[WizeOne]

Re: Whole house Fans.

I used to have a house in SoCal that had an old swamp cooler on the roof. (circa 1952) The humidity in the area had long increased passed the time that evaporative cooling was of much use. During my 7 years in that house I never even tried to see if the water pump worked on that thing but the big squirrel cage fan still did work.

One thing about a central swamp cooler was that it had huge ducts going to each room. They were probably 4 times the diameter of typical refridgeration A/C ducts.

I would come home from work on a hot day, open all the sliding doors and turn on that squirrel cage fan. It would cool that house down in no time. This, of course, assumed that the early evening air was cooling down outside. It did no good if it was one of those hot August nites. When I got married and the Mrs moved into my house, I had that swamp cooler and all it's ducts ripped out and installed a roof mounted heat pack A/C.

No more could we rapidly flush hot air out of the house. I was really disappointed because I do not like A/C unless it is a particularly hot muggy day.

I always vowed if I ever built a house I would include a high volume duct system along with any HVAC ducting. Never did build that house and probably won't but no doubt unless you are in the hottest and muggiest of climates, high volume air flushing of a house works real well.

 

[Beefer]

Re: Whole house Fans.

From a personal stand-point, they rock. We had one in the house I grew up in, and it really helped since we didn't have AC.

From a professional stand-point (I'm a home inspector), they rock. They are (considerably) less expensive to operate then an AC unit, and make a house comfortable, especially at night.

If you have any appliances that produce carbon monoxide, be sure to install a CO detector at the same time as the fan if you don't already have one. As Tackwasher said about his friend's house, these things will cause a reverse draw on exhaust systems, which causes deadly gases that are trying to escape to be brought back into the living space. For safety, and for proper cooling operation, have multiple windows on the lowest level opened a crack. If security is a concern, do the upper level instead.

 

[OldePharte]

Re: Whole house Fans.

Ours is on a timer. Typically, we set it for 4 to 6 hours depending on the cooling needed. We crack open the master bath windows (on the 2nd floor), and it draws air into the bedroom, down the hall, and up through the roof vents.

I bought a magnetic vent cover that is installed during the winter months.

 

[ebry710]

Re: Whole house Fans.

Ours is on a timer. Typically, we set it for 4 to 6 hours depending on the cooling needed. We crack open the master bath windows (on the 2nd floor), and it draws air into the bedroom, down the hall, and up through the roof vents.
I bought a magnetic vent cover that is installed during the winter months.

I like the timer and the magnetic cover. Does anyone know how much electricity they use?

 

[salty87]

Re: Whole house Fans.

No need to cut ceiling joists, just head them off.

can someone elaborate on this?

 

[OldePharte]

Re: Whole house Fans.

Most ceiling fans should fit in between the ceiling joists. These support two sides. You need to install two pieces of wood between the joists to support the fan's other two sides. You may be able to get by with a 2x4, but look at the fan installation instructions to be sure. You will also have to run electrical to power the fan and controls. You should get a licensed electrician to do this.

 

[ebry710]

Re: Whole house Fans.

can someone elaborate on this?

An attic fan (usually 15") doesn't need ceiling joists cut, but a whole house fan is usually 23". Some joist are 16" on center and others are 24" on center. Unless you have 24" on center joist, you will have to cut the joist then place a perpendicular header to frame it

Also, if you want to center the unit in a hallway, you will probably also have to cut joist.

 

[arboldt]

Re: Whole house Fans.

As in most things, there are trade-offs. A lot depends on where you live and the normal climate.

A whole-house or ceiling fan can make things a lot more comfortable in most areas, particularly if you have a cooler basement or cooler outside temps. You do have to be careful about balancing air pressure however.

BUT, in the northland where winter heating expense outweighs summer cooling, a ceiling fan's value is dubious. In most attics, you're looking at 8" - 16" of insulation plus sealing all air leaks from the house to attice (ceiling electrical boxes, holes in top plates for wiring, around furnace flues, etc). Usually it's recommended to fit a *tight* sealing insulation box with at least 8" rigid styrofoam insulation over the opening or you'll pay megabux all winter long. And for us, often the outside evening temps don't drop that much, so the attic fan would accomplish air movement but no cooliing.

A couple years after we bought this house, we put the $$ into additional attic insulation and ventilation, which prevented summer heat buildup from heating up the living space, and also helped our winter heating costs.

I guess I'd suggest you really think about payback and comfort enhancement of different ways of investing your money.

 

[Xcusme]

Re: Whole house Fans.

can someone elaborate on this?

The units I installed were boxed...the fan assembly was mounted on 1x4 frame. This frame sits on top of the joists. It's a simple matter to use short lengths of 2x lumber the same dimension of the joists to "head off" to openings below the fan box to close the openings. The louvers are made to straddle a center joist. Google Whole House Fan Installation....pretty easy really.