I’m looking at putting in a whole house fan. We live in Charlotte where the summers definatly require AC; however the late spring and early fall would be a great time for a WHF to cut energy consumption. I’m looking at 2 models:
http://www.wholehousefan.com/hv-1600.html
http://www.hvacquick.com/asfnconfig.php?fm=WHF
Has anyone used one of these? Other suggestions greatly appreciated.
Thanks, Bob
Replies
Don't even hesitate. We had one in our old farm house with lots of mature shade trees around. Only had to use the ac window units maybe a week out of each year during the real dog days. It's really good for the health of the house on the one hand, especially on the really clear, dry, cool days, it gets rid of the stale air. On the other hand, watch out during the spring when the pollen count is high, ragweed and all that.
We have a Sears unit that is at least 20 years old, still running fine. No maintenance required since it was installed (knock wood-grained Formica).
We use it during the summer when humdity isn't too bad. Probably 500-2000 hours per year, depending on weather.
Our Sears unit is direct-drive, variable speed, maybe 24" diameter (from memory). We hardly ever run it full speed in our 2000 sq ft house.
On these "lower-flow" (500-1500 cfm) whole house fans, how much attic venting is required? I have a very small area in which I could mount one, and it would have to be a wall-mount at that, at the top of the stairs to my 2nd floor. There are three or so 12x12ish rectangular (probably 8" diameter hole) roof vents at the highest ridge of the roof, and I imagine those would give adequate venting, but I'm not sure...
Anyone?
Other than that, I think a WHF would be a great compliment to my restored windows! Kansas City springs and falls are great for WHFs...
My folks had one in their house in MO in the mid-60's and it was great - except for the noise. It was in the hall, near the bedrooms, and had a mechanical timer. Pop usually set it to run a couple of hours after bedtime and it definitely made for some good sleeping.
I've thought of putting one in my house (in CA) but have settled for ceiling fans in all the rooms. During the summer, we leave the windows (double pane, low-e) open all night then close the place up during the day. It stays cool inside until late afternoon when we open up the windows on the shady side of the house.
Do you have any eave vents? Probably somewhere there's a formula for the square inches of venting you need per CFM. You'd add the area of the rooftop and eave vents (and any gable vents) to figure this.I don't know if there are any standard units that can be mounted vertically, though you could probably cobble something with a Fantech duct fan (or maybe two) and appropriate ductwork and grilles.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
I grew up in Ohio. Family house had a very large (3') whole house fan. Worked wonders for cooling the house down in the summer.
Ours was gable end mounted in the attic, and the attic door left ajar when in use.
I am aware that there are whole house fans that mount in the attic or roof itself and use draft operated louvers mounted in the ceiling or walls to vent the living space.
They do work , I would put one in here but our summers just don't warrant them .
i can tell you this,you don't want wind turbines to vent your attic fan,it will shoot the bearings about ever 2 months.unless you could figure out a way to hook a genarator to them,they spin at about 1000rpm's larryhand me the chainsaw, i need to trim the casing just a hair.
I put an HV-1600 in my brother's house. It's quiet, but in my opinion, it does not move enough air.
On the other hand, the house we bought last year has a 50 year old 30 inch 1 speed fan that definitely moves enough air. But it's really loud, and needs a slow position for when you don't want to suck the glass out of the windows. I will probably replace it this season with one that has a variable speed motor. The 1/3 hp motor in this unit is a standard induction motor, and can't be speed-controlled, and I haven't been successful in finding a variable-speed motor in this hp class that's less than replacing the whole fan.
There are two "gotcha's" when putting in a whole-house fan.
The first is that you've got to have sufficient attic space venting to let the little jewel blow the air someplace other than back down your bathroom vents. I know, that can't happen if those are vented outside like they are supposed to be.:)
The second is that if you have gas appliances like a water heater or furnace, you better have enough windows open when you fire up the whole house fan, or you are going to suck the flame products right into the house. And not some of them, but ALL of them.
Oh, yes, there's a third. If your new unit doesn't include an automatic insulated door, be prepared to cobble one together. A 30" diameter hole in your ceiling really lets the hot air out in the winter and the hot air in during the summer if it isn't insulated, side and top.
Mike D