Attic Fan vs Whole House Fan? - Tilted Forum Project Discussion Community

gonadman · 05-26-2004, 06:52 PM

I have a huge attic. The shingles are black and the attic builds up a lot of heat, which keeps the bedrooms pretty hot all spring and summer. I need to ventilate the hot air so I originally decided to install some appropriate sized fans on a temperature controlled switch.

I recently saw some whole house fans advertised. They install in the upstairs hallway and open louvres in the ceiling, which draw the warm air out of the house and out through the attic vents. I wonder which might be better for the house.

The attic fans can work anytime to vent the attic, but the whole house fan can take advantage of some cooler nights by drawing in the cool air through the windows when I otherwise would have to run the AC. The only disadvantage would be during hot days and nights, I couldn't run the whole house fan as it would draw in the hot air from ouside. Which should I get? Maybe both?

I would be interested in hearing the opinion of some of you that have one or the other and the advantages and disadvantages of each.

onetime2 · 05-27-2004, 05:10 AM

I am not a big fan of attic fans. They're better than no ventilation but the controls burn out far too often. A ridge vent combined with vents under the eaves is a far better solution IMO.

Basically a ridge vent is created by cutting off a couple of inches of the sheathing under the shingles on either side of the point of your roof. A section of ridge vent material is attached over the hole to prevent the elements from entering the attic. If you don't already have them, vents need to be placed in the eaves of your house (that section of the roof that hangs over the walls). There needs to be a pathway of uninterrupted air flow from the eaves past any insulation at the top of the walls. Then the natural convective currents will allow hot air to go out the ridge vent while cooler air is brought in through the eaves.

b_angelo · 05-27-2004, 07:53 AM

have you looked into the turbin fans. We had one in our house for years. They were removed to add a second story. My father said that it "made a whale of a difference" in the attic. I do agree that they are not the prettiest thing to look at.

Mondak · 05-27-2004, 11:45 AM

I had a whole house fan growing up in NJ and it kicks total ass. I am surprised that we don't see more of these, but I suppose more people are opting for A/C instead. Depending on the humidity where you live you may not need A/C (Or want to pay for it). These fans can change everything and they are really cheap compared to the cooling they will bring.

Don't worry about when it is hot outside. The moving air will be cool and work either way. The thing is with these fans, is you really may not need to run them full time. If you have the fan on a timer that goes to say 1 hour, that would do the trick. You turn this sucker on and in a few minutes the whole house is vented. If you want to target a specific area, close some windows and doors at the top level and open them up downstairs. That is a nice effect.

stldickie · 05-27-2004, 01:04 PM

The ridge vent is the standard for preserving your shingles, but the house fan creates a nice breeze...unless it is really hot. The house fan does suck if you have seasonal allergies.

clavus · 05-28-2004, 09:01 AM

Attic fan is primarily there to preserve your roof.

Whole house fans are there to...well, you already know this one.

edmos1 · 05-28-2004, 02:47 PM

I am not sure you want to use a whole house fan that often if it is that hot, unless you are taking advantage of the cooler outside weather, (nightime summer) the result would be cooling the house and the attic at the same time.

EVIDENT · 05-30-2004, 09:01 PM

We had a "whole house fan" when we lived in Sedona. Man, that thing rocked. I'm also suprised you don't see those things around more often - I guess it's effectiveness depends on the climate it's used in.

gonadman · 05-31-2004, 07:52 AM

I have a ridge vent and vents under the eaves. I geuss my main thought was spring and fall. Even with mild temps- upper 70's to lower 80's, the attic heats up so much that the ceiling is warm, and I need to run AC just to cool down, so I'm running AC from May thru September. I figure cooling down the attic and house with the fan in milder weather may save me a total of say, 2-3 months of AC over the course of a year.

In the heat of July and August, when temps stay in the 90's, we also have high humidity, so even a breeze isn't too comforting. I probably wouldn't get much use from the fan then.

Sounds like those of you with the whole house fans really enjoyed them.

kazoo · 05-31-2004, 06:17 PM

I have a whole house fan, and also the benefit of 70'+ trees. They block the majority of afternoon sun, and the fan creates a pleasant breeze in the house during the warmest days.

Spanxxx · 06-16-2004, 09:22 AM

My parents had a whole house fan when I was growing up.. and well, I guess the still do seeing as they haven't moved. They were two massive fans in the central hallway of the house that worked amazingly well. Of course, now I can't remember the last time they actually used them, but I do remember us using them on occasion. They are great during the transitional months. However, the humidity is the problem. They live in KY and it's humid enough that there are only a very few months where the fans are comfortable otherwise you are left with a nice "wet breeze" as you are trying to go to sleep. Also, you have to keep your windows open obviously and that may or may not be something you want based upon how well they are sealed (in terms of letting critters in) and especially if you suffer from allergies.

They do create quite a nice breeze though and do help to cool the house off, or at least create a really nice draft. It might also depend on the layout and design of your home as to how well they will work. Just a thought.

gonadman · 06-18-2004, 08:32 AM

Humidity a problem here too. I agree the transitional months are the best. My AC is two zoned- upstairs and downstairs, so I can also leave the upstairs AC off during the day, then as evening cooler temps arrive, I can run the fan with the upstairs windows open and quickly drop the hot temps- even if I still need to run the AC, it'll be less energy with an attic at 80 not 110 and upstairs at 80 not 90 degrees.

Some nice fans on the market. I need a big one. The all welded models claim less noise due to sqeaking, etc. but are almost twice as expensive. Any of you with whole house fans experience a lot of rattles and sqeaks? Is it worth the extra bucks for welded? This is something I plan to use for many years.

agball · 06-18-2004, 10:32 AM

I agree with Mondak, the whole house fan is the best, it will cool the house by sucking the air through open windows (assuming its cooler outside than inside) as well as cool the attic. I have one in my house & when I get home from work it might be 85 degrees inside. When I open all the windows & turn the fan on, within 10 miuntes the temp inside drops 10 degrees.

05-26-2004, 06:52 PM	#1 (permalink)
gonadman Psycho Location: Philly	Attic Fan vs Whole House Fan? I have a huge attic. The shingles are black and the attic builds up a lot of heat, which keeps the bedrooms pretty hot all spring and summer. I need to ventilate the hot air so I originally decided to install some appropriate sized fans on a temperature controlled switch. I recently saw some whole house fans advertised. They install in the upstairs hallway and open louvres in the ceiling, which draw the warm air out of the house and out through the attic vents. I wonder which might be better for the house. The attic fans can work anytime to vent the attic, but the whole house fan can take advantage of some cooler nights by drawing in the cool air through the windows when I otherwise would have to run the AC. The only disadvantage would be during hot days and nights, I couldn't run the whole house fan as it would draw in the hot air from ouside. Which should I get? Maybe both? I would be interested in hearing the opinion of some of you that have one or the other and the advantages and disadvantages of each. __________________ For me there is only the traveling on paths that have heart, on any path that may have heart. There I travel, and the only worthwhile challenge is to traverse its full length. And there I travel, looking, looking, ...breathlessly. -Carlos Castaneda

05-27-2004, 05:10 AM	#2 (permalink)
onetime2 Junkie Location: NJ	I am not a big fan of attic fans. They're better than no ventilation but the controls burn out far too often. A ridge vent combined with vents under the eaves is a far better solution IMO. Basically a ridge vent is created by cutting off a couple of inches of the sheathing under the shingles on either side of the point of your roof. A section of ridge vent material is attached over the hole to prevent the elements from entering the attic. If you don't already have them, vents need to be placed in the eaves of your house (that section of the roof that hangs over the walls). There needs to be a pathway of uninterrupted air flow from the eaves past any insulation at the top of the walls. Then the natural convective currents will allow hot air to go out the ridge vent while cooler air is brought in through the eaves. __________________ Strive to be more curious than ignorant.

05-27-2004, 11:45 AM	#4 (permalink)
Mondak Industrialist Location: Southern California	I had a whole house fan growing up in NJ and it kicks total ass. I am surprised that we don't see more of these, but I suppose more people are opting for A/C instead. Depending on the humidity where you live you may not need A/C (Or want to pay for it). These fans can change everything and they are really cheap compared to the cooling they will bring. Don't worry about when it is hot outside. The moving air will be cool and work either way. The thing is with these fans, is you really may not need to run them full time. If you have the fan on a timer that goes to say 1 hour, that would do the trick. You turn this sucker on and in a few minutes the whole house is vented. If you want to target a specific area, close some windows and doors at the top level and open them up downstairs. That is a nice effect. __________________ All truth passes through three stages: First it is ridiculed Second, it is violently opposed and Third, it is accepted as self-evident. ARTHUR SCHOPENHAUER (1788-1860)

05-28-2004, 09:01 AM	#6 (permalink)
clavus pow! Location: NorCal	Attic fan is primarily there to preserve your roof. Whole house fans are there to...well, you already know this one. __________________ Ass, gas or grass. Nobody rides for free.

05-30-2004, 09:01 PM	#8 (permalink)
EVIDENT Tilted Location: DFW	We had a "whole house fan" when we lived in Sedona. Man, that thing rocked. I'm also suprised you don't see those things around more often - I guess it's effectiveness depends on the climate it's used in. __________________ " " - Silent Bob

05-27-2004, 07:53 AM	#3 (permalink)
b_angelo Tilted	have you looked into the turbin fans. We had one in our house for years. They were removed to add a second story. My father said that it "made a whale of a difference" in the attic. I do agree that they are not the prettiest thing to look at.

05-27-2004, 01:04 PM	#5 (permalink)
stldickie Addict	The ridge vent is the standard for preserving your shingles, but the house fan creates a nice breeze...unless it is really hot. The house fan does suck if you have seasonal allergies.

05-28-2004, 02:47 PM	#7 (permalink)
edmos1 Daddy Location: Right next door to Hell	I am not sure you want to use a whole house fan that often if it is that hot, unless you are taking advantage of the cooler outside weather, (nightime summer) the result would be cooling the house and the attic at the same time.

05-31-2004, 07:52 AM	#9 (permalink)
gonadman Psycho Location: Philly	I have a ridge vent and vents under the eaves. I geuss my main thought was spring and fall. Even with mild temps- upper 70's to lower 80's, the attic heats up so much that the ceiling is warm, and I need to run AC just to cool down, so I'm running AC from May thru September. I figure cooling down the attic and house with the fan in milder weather may save me a total of say, 2-3 months of AC over the course of a year. In the heat of July and August, when temps stay in the 90's, we also have high humidity, so even a breeze isn't too comforting. I probably wouldn't get much use from the fan then. Sounds like those of you with the whole house fans really enjoyed them. __________________ For me there is only the traveling on paths that have heart, on any path that may have heart. There I travel, and the only worthwhile challenge is to traverse its full length. And there I travel, looking, looking, ...breathlessly. -Carlos Castaneda

05-31-2004, 06:17 PM	#10 (permalink)
kazoo Psycho Location: Where the night things are	I have a whole house fan, and also the benefit of 70'+ trees. They block the majority of afternoon sun, and the fan creates a pleasant breeze in the house during the warmest days. __________________ There ain't nothin' more powerful than the odor of mendacity -Big Daddy

06-16-2004, 09:22 AM	#11 (permalink)
Spanxxx Psycho Location: Under my roof	My parents had a whole house fan when I was growing up.. and well, I guess the still do seeing as they haven't moved. They were two massive fans in the central hallway of the house that worked amazingly well. Of course, now I can't remember the last time they actually used them, but I do remember us using them on occasion. They are great during the transitional months. However, the humidity is the problem. They live in KY and it's humid enough that there are only a very few months where the fans are comfortable otherwise you are left with a nice "wet breeze" as you are trying to go to sleep. Also, you have to keep your windows open obviously and that may or may not be something you want based upon how well they are sealed (in terms of letting critters in) and especially if you suffer from allergies. They do create quite a nice breeze though and do help to cool the house off, or at least create a really nice draft. It might also depend on the layout and design of your home as to how well they will work. Just a thought. __________________ I think that's what they mean by "nickels a day can feed a child." I thought, "How could food be so cheap over there?" It's not, they just eat nickels. - (supposedly) Peter Nguyen, internet hero

06-18-2004, 08:32 AM	#12 (permalink)
gonadman Psycho Location: Philly	Humidity a problem here too. I agree the transitional months are the best. My AC is two zoned- upstairs and downstairs, so I can also leave the upstairs AC off during the day, then as evening cooler temps arrive, I can run the fan with the upstairs windows open and quickly drop the hot temps- even if I still need to run the AC, it'll be less energy with an attic at 80 not 110 and upstairs at 80 not 90 degrees. Some nice fans on the market. I need a big one. The all welded models claim less noise due to sqeaking, etc. but are almost twice as expensive. Any of you with whole house fans experience a lot of rattles and sqeaks? Is it worth the extra bucks for welded? This is something I plan to use for many years. __________________ For me there is only the traveling on paths that have heart, on any path that may have heart. There I travel, and the only worthwhile challenge is to traverse its full length. And there I travel, looking, looking, ...breathlessly. -Carlos Castaneda

06-18-2004, 10:32 AM	#13 (permalink)
agball Insane Location: Long Island	I agree with Mondak, the whole house fan is the best, it will cool the house by sucking the air through open windows (assuming its cooler outside than inside) as well as cool the attic. I have one in my house & when I get home from work it might be 85 degrees inside. When I open all the windows & turn the fan on, within 10 miuntes the temp inside drops 10 degrees. __________________ "A friend with weed is a friend indeed"