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Keith Starosta
07-14-2005, 7:59 AM
The LOML has given me a direct order......"We NEED a whole house fan!!!" So....I guess I'm going to install a whole house fan. :D

I was doing some window shopping last night, and was puzzled by a few things I was seeing on the boxes. Keep in mind, my knowledge of motors is veeeeeery slim, so be kind.

- What are the merits of a belt driven fan over that of a direct drive fan, or vice verse?
- What do they mean when it states, "X number square inches of exhaust vents in attic?

The wiring and things of that nature are no problem, as hopefully the rest of the will be once these questions are answered.

Thanks, guys!!

Keith

Tyler Howell
07-14-2005, 8:55 AM
With a belt drive you can replace just the motor.

If the motor fails on a direct drive you're usually looking at $$$$ close to complete fan replacement.

Ralph Barhorst
07-14-2005, 9:51 AM
The whole house fan will require a fairly large amount of exhaust area in the attic or the fan will not be able to work at maximum efficiency.

Our old house had a whole house fan and it also had a three foot by three foot vent installed in the attic to allow for the air exhaust.

Check the requirements for vent area on the box to determine if your attic has enough vents. The larger the fan the more exhaust area you will need. Also, take this into consideration when buying the fan as the expense of adding a larger vent in the attic may cost more than the fan.

Lee Schierer
07-14-2005, 9:56 AM
You can't blow air into a closed box with a fan. So if your attic doesn't have enough vent area to let the air out, you will not get good air flow through the fan and it won't do the cooling job it is supposed to be doing. Also you will need to insure that you always have enough windows open elsewhere in thehouse to let air in. Measure your vents and see if the total open area is greater than the amount suggested by the fan manufacturer. If the area isn't larger either install more vents or get a smaller fan.

Ease and cost of motor replacement would be the only consideration I can think of for choosing a belt drive set up over a direct drive motor.

Tim Burke
07-14-2005, 10:33 AM
- What are the merits of a belt driven fan over that of a direct drive fan, or vice verse?
- What do they mean when it states, "X number square inches of exhaust vents in attic?
Keith

Belt drive vs direct drive - Belt drive is quieter since the motor is not mounted directly to a ceiling joist. Generally, the smaller fans are direct drive, the larger fans are belt drive. I had a direct drive in my old house, would advise getting a belt drive due to noise.

Square inches of opening - you have to count all of the openings in your attic to vent the fan, add up the total area, derate for factors like bug screens.

You can look at airvent.com to get good installation information.

Tim

Dennis Peacock
07-14-2005, 10:52 AM
Tim Burke has you headed in the correct direction.

In my last house, I installed a whole house fan. Get one with a three speed fan if you can. Low moves decent air, medium moves considerably more air and HIGH...your screens on your windows will become convex on the inside of the house and concave on the outside. LOTS, LOTS of air movement. Sure wish I had one in my current house!!!!!! :(

Go belt drive and make SURE you have enough roof ventilation to allow that air from the fan to exhaust out without any backpressure.

Keith Starosta
07-14-2005, 11:35 AM
Thanks for all the information, guys. I really appreciate it!

Tim, thanks for the website reference. I will definitely check it out.

Here's another question...can I consider the ridge vent when adding up all the sq. inches of venting in the roof?

Keith

Dennis Peacock
07-14-2005, 11:47 AM
Here's another question...can I consider the ridge vent when adding up all the sq. inches of venting in the roof?

Keith

Ridge vent can account for a lot of air movement and can be counted as part of the total air flow out of your attic. I installed a ridge vent for just this purpose. :D Worked really good.!!!! ;) :D

Pete Lamberty
07-14-2005, 12:51 PM
Keith, another thing that you have to be aware of is how high the roof is above where the whole house fan is going to be. It's not a good thing if the inner roof is only a couple of feet above the fan. Another way to circumvent all the vents is to wire in an attic fan that will remove the exhaust air from the house. My brother in law needed to do this and he wired it so that the house fan could not be turned on unless the attic fan was on. Your vent requirements will probably be based on "free" air space. The "free" air space of a vent is usually stamped on the vent. You will be glad you put one in. Those fans are great.

Ken Garlock
07-14-2005, 2:21 PM
Keith, it is worth noting that a whole house fan does NO good during the heat of the day. All you do is suck in the hot outside air :p The real advantage of the whole house fan is after dark when the outside air cools off.

I grew up with a whole house fan that my Dad constructed from parts. It sounded like a Cessna 150 taxiing :( , but it did a great job after dark. We would close up the house except for the bedroom window and it made sleeping quite reasonable on the hottest of nights. Dad coupled a thermostat to the fan so that it would cut off at 72 and back on about 74(?). On several occasions, it ran all night. :(

Jerry Olexa
07-14-2005, 2:53 PM
These are wonderful when conditions are right as Ken says: at night when air is cool outside and home is stuffy inside. It draws the cool air in powerfully. I installed a couple of these. Current home doesn't have one. Get a belt driven one and amt of venting is critical .I found in one home when checking the vents in attic, the builder covered the vent w insulation board and forgot to trim around the vent. So that was a quick fix. You'll like it and pretty easy to install. Pick a cool day...Those attics are hot!!

Bob Johnson2
07-14-2005, 3:21 PM
I found soffet venting all around (perforated vinyl) coupled with ridge vents made a considerable difference during the day, letting out the overheated attic air through the ridge vent. I too only run my fan when the outside air is cooler then the inside.

Jack Wood
07-14-2005, 6:10 PM
Keith having grown up in the deep south I know a thing or two about whole house attic fans and one thing I have not heard anyone else mention is that along with that cool night air you will pulling in lots of moisture, dust and pollen:(now in the days before home AC this was not even a consideration as you were going to have the windows open anyway, but most people who put in AC units never turned the house fan on after that. The neat thing about AC is not only does it cool or heat your home but it removes excess humidity that can cause mold and mildew in your bedrooms and closets. Now if you live in Arizona or somewhere that might not be a problem but here in Alabama where the humidity can run in the 80's and 90's regularly it is something to consider. And then theres the other things, when you turn that fan on not only are you taking in air but all of the nasty little things like dust and pollen. My son's allergist told us to never open the windows to let in the "fresh" air as the pollen also came in with it. Well this did bring back some memoies for me, but they were of laying in bed and feeling damp from the night air something I'd rather not do again:rolleyes:

Chris Padilla
07-14-2005, 6:12 PM
http://www.hvacquick.com/

Keith, I have the Tamarack HV1000 in my house. Installed it two years ago and we really like it. It isn't terribly loud (we can sleep with it on even though it is right outside our bedroom) and it was a pretty straight-forward install.

Bonus was that our local utility company had a nice lil' rebate on it so look into the rebate section for your local utility...they might have something and this house fan might just qualify.

Gary Max
07-14-2005, 6:19 PM
The first year I lived here I went out and bought a whole house fan. I mounted it in the attic. This was not a big money fan---maybe just over a $100.00 at Mernards. Best money I ever spent. Thermostat control set at 110 drgrees---it keeps the attic from building up as much heat. I looked for a good warranty---5 years.

Jim Andrew
07-14-2005, 11:08 PM
I have a whole house fan mounted in the hallway ceiling. I put a timer switch in so I could just twist it on for 30 or 60 minutes. The switch crapped out the first year. My neighbor put his fan in the garage, and put a screen door on the door
from garage to house so he could leave the door open. Then he just shuts all
the windows but the bedroom, and opens the door to the garage and turns the
fan on. The big garage door must be closed, along with walkout door and window obviously, or it will not suck air through the bedroom. Works good on
cool evenings. Jim

Keith Starosta
07-15-2005, 5:47 AM
Thanks alot, guys!! This is all great stuff, and gives me lots to consider. I also grew up with a whole house fan, but I didn't help my Dad install it, and I never really gave it much thought, other than to turn it on. I gave the attic a pretty good look yesterday, and I think I may have to cut in a couple of vents. I didn't take measurements on the ridge vent, so I'm not certain if it's going to be big enough. I'll keep ya'll updated on my progress....

Keith

Larry Browning
07-15-2005, 8:17 AM
When did the name of these things change? When I was growing up they were called attic fans.

Frankie Hunt
07-15-2005, 8:59 AM
Hey Larry,

These are 2 different animals. Attic fans exchange the air in the attic with outside air. Whole house fans exchange the air in the house with outside air through the attic.

Here is a good link on them: http://www.atticfans.com/

Here's 2 pictures. The top one is the attic fan. The bottom one is a whole house fan.

<O:p</O:p
Frankie

Frankie Hunt
07-15-2005, 9:16 AM
I have a whole house fan. We usually run it during the spring and the fall. I much prefer outside air to inside AC air. (except when it is hot and humid of course). We especially love it in the fall.

Get the biggest belt drive one you can fit in your house. The bigger, the more blades, the better it is. You can run the big ones on low speed and you hardly notice them running. I have mine in the hallway which is a central location. In nearby rooms you hardly can hear it. My FIL had a direct drive one. It was very noisy. Not only more noisy on the same speed setting as mine, but you had to run it much faster to move the same amount of air. This compounded the noise problem.

I would not want to be without one, AC or not.

Frankie

Jerry Olexa
07-15-2005, 9:48 AM
Keith, I forgot to mention (LOML reminded me @ dinner): get a timer switch. Had a 1 hour originally and then installed a 3 or 4 hour switch later. Makes a big difference. This way you don't wake up 3AM freezing...Enjoy...They are great

Keith Starosta
07-15-2005, 11:57 AM
Good tip, Jerry!! Thanks again!!

Keith

Larry Browning
07-15-2005, 1:16 PM
Hey Larry,

These are 2 different animals. Attic fans exchange the air in the attic with outside air. Whole house fans exchange the air in the house with outside air through the attic.

Here is a good link on them: http://www.atticfans.com/

Here's 2 pictures. The top one is the attic fan. The bottom one is a whole house fan.

<O:p</O:p
Frankie

Frankie,
What is now apparently called a whole house fan used to be called an attic fan. Some time between 1955 and today the name was changed. Either that or everyone I knew back then had it wrong. My theroy is, the thing that is now called attic fan stole the name and renamed the original to "whole house fan" and then forgot to tell me about it. HOW RUDE!!!
All I know is, my childhood was filled withwarm summer nights where the ATTIC FAN provided a nice cool breeze and a soothing low rumble to put me right to sleep. I think I will never be able to call it a whole house fan, it just doesn't have the same ring to it. If that confuses some young whipper snapper, so be it. It's an ATTIC FAN, that other thing is something else. Maybe an attic power ventilator or overhead air space circulating blower, anything but attic fan!!