Whole House Fans Vs Attic Fans

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Difference Between Whole House Fans and Attic Fans

As summer quickly approaches I wanted to share an archived post about whole house fans and gable attic fans. This post was written to help a reader decide which type of attic fan was best for her home.

Marrisa wrote to me and wants to know about whole house fans vs attic fans.

I’ve been considering installing an attic fan in my house, and wondered what your thoughts were. First, is an attic fan the same thing as a “whole house fan?” I’ve seen sites apparently use the phrases interchangeably, though I don’t know if that’s correct. Second, do these fans save a significant amount of energy versus central air?

There is a huge difference between Gable Attic Fan Whole House Fans Vs Attic Fans and a Whole House Fan Whole House Fans Vs Attic Fans. A gable attic fan is mounted to one of the gable walls in the attic. The fan is used to remove hot air from the attic space in order to limit heat transfer to the living space below. A whole house fan is mounted in the ceiling between the living space and that attic. It is used to suck warm air out of the living space up into the attic. The pressure created by the suction forces that warm air out of the venting of the roof and it helps draw cooler outside air in through open windows in the house.

gable attic fan 300x300 Whole House Fans Vs Attic FansGable Attic Fan

Gable Attic Fans – are mounted to the gable wall inside the attic behind a decorative louver. The gable attic fan is connected to a proper power supply and a timer. The timer allows the fan to run during the hottest portion of the day. The gable attic fan helps reduce the attic temperature to help prevent heat transfer down through the insulation and into the living space. Gable attic fans are typically much cheaper than whole house fans and also easier to install.

Whole House Fan

whole house fan 300x203 Whole House Fans Vs Attic FansWhole House Fans – are mounted in the ceiling between the living space and attic. They are typically located in a central hallway to help evenly remove warm air from the living space. When a whole house fan is turned on it helps draw warm air out of the living space while drawing in cooler outside air from open windows.

This system is most effective when the temperature outside drops below the temperature inside the house. Whole house fans can be very effective in cooling down a house in the morning and evening hours. In some parts of the country they can be a very inexpensive alternative to central air.

Whole house fans typically have some type of louver and/or insulated door that closes when the fan is shut off. This helps keep warm and cold air out of the living space when the unit is not being used.

Attic Fan Installation

The other part of Marissa’s question was about installing these units herself. I’d rate the installation of a whole house fan as a difficult / advance home improvement project. I’m not sure I would recommend this project to most DIY folks. Having said that, if you’re really comfortable with electrical work, framing and cutting drywall then you can probably tackle the job. You can probably cut in the unit and get it ready then hire an electrician to wire it up.

Do any of you have a whole house fan? Would you recommend one for others as an alternative to central air?

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52 Comments »

  • Marissa says:

    Thank you for the response, Todd! I appreciate it. I’d love to get a whole house fan put in, since the outside air temperature is often cool enough to be comfortable, if I could just get it *moving* through the house. Sounds like a whole house fan would fit the bill nicely. (FAST response, too!) Thanks again!

  • Jennifer says:

    We have a non-working attic fan.. I would say gable, but we have no gables. I’ve been wondering what might be required to get it working again… it sure would be nice to have in the summer!

  • Green Me says:

    Timely post! Here I am making up a budget for home improvements, with an attic fan at the top of the list! The thing that had me worried, is our one estimate told me they’d have to cut a hole in the roof (this was over the phone) and then my dad got me all worried about them doing it wrong and our roof leaking. However, we do have a little gable vent just like that in our attic, so maybe it just needs a fan installed…or maybe there is a broken one already up there!

    I have one more question…what about solar attic fans? I was talking to a green building guy earlier this summer who recommended one, but again my dad said that regular attic fans probably save more money in AC costs than the use in electricity any way. And the solar fan costs several hundred dollars more upfront. What do you think?

  • Todd says:

    @ Green Me – It is possible that more ventilation is needed in the roof, eaves, gable or soffit to allow for the volume of air being moved by the whole house fan. If you already have gable vents they might just need to be resized. I would get multiple quotes from reputable companies and ask lots of questions.

    Solar attic fans are a great idea, however, they are not the same as a whole house fan.

  • jamie freitas says:

    We have a whole house fan currently in our home, as well as put them into all the homes we build. I strongly recommend & believe it to be highly effective for a quick-response cooling of the entire house!! I grew up in NJ, in a home w/ both central air as well as a whole house fan- we all enjoyed the natural air far more than the produced chilled air of the AC!

    Easy to install to boot!! :o) It is placed between the floor joists- and can be positioned nearly anywhere w/in the parameters of the central hall (we aim to not have it w/in direct sight when you come up the stairs for better esthetics). Genius!

  • ecto says:

    I grew up with a whole house fan, if not to hot outside it was great. And when the AC went out once it was a life saver. we would open only the windows in the rooms we were in to get max airflow from those windows. it creates an artificial breeze coming in from the outside. I would install both. the gable fan ( I would presume it is on a temperature controlled switch) can cool the attic when your not using the whole house fan to help keep your bills down even more.

  • Mark says:

    When I checked out solar fans, they were only 500 CFM. (They move 500 cubic feet of air per minute). Electric ones are usually 1200 to 1600 CFM, and they run at night. (Mine shuts off at around 10:00 usually) If you are considering a solar fan, remeber, your AC may run more than if you got a powered attic fan.

  • C Muschlitz says:

    I have an attic fan which is not working. It’s approx. over 21 ys. old and was in the house when I bought it.. The fan is installed in the roof. I’ve been quoted a price of $500.00 to replace (prob. doesn’t include labor, the quote was left on my phone message ). Since, what I have is so old, will it be hard to replace and not leave a leaky roof? Also, is this how it’s done currently? Good price? It’s already getting very warm in the crawl space attic. Thanks

  • Brian says:

    This is great info. We bought an older home and are planning to get a new roof installed this summer. The attic has floor boards for storage and a pull down ladder. Since we plan to store stuff in the attic, will we still be able to install a house fan or will we only be able to have an attic fan installed. I’d like to have this figured out before the new roof goes in so any holes in the roof can be taken care of with the roofers. Based on the location of the pull-down steps, it looks like the house fan will have to be installed close or if not next to the pull-down steps…any issues with this?

    • Todd says:

      @ Brian – Many people have attic storage and whole house fans. The only issue in my mind is dust/wind near stored materials. You just need to keep sufficient distance from the fan to stored materials. Whole house fans are a very effective way to cool your home. Best of luck!

  • gaman says:

    Bought a home w/whole house fan installed in hallway. It does suck in the outside air and pollen and dust. We recently removed it and will be installing gable fans to remove hot attic air only, without the problem of dust and pollen being drawn in. There is something to be said about clean AC air.

    • Erik says:

      Your point about dusty air being sucked in really changed my mind about a whole house fan! Nowhere else did anyone mention this… and in my area, there is a ton of sandy silt in the air. Thanks so much. You saved me a lot of money, time, and aggravation!!!

      Erik

  • Snow says:

    I had a very powerful and noisy attic fan that really pulled the air up on out, but I would like one of the new quiet whole house fans instead. Does anyone know if you can get them to run on a timer? Or does anyone know about an adequate solar power whole house fan?

  • Dean says:

    Hi. Some general comments on fans. The full house fan will tend to pressurize the attic space and if the attic is close to being “air tight” a higher pressure will be created on the discharge of the fan and it won’t be able to move the designed air volume, so the attic needs to be able to breathe feely. The attic gable fan also needs a sufficent inlet area for the outside air at the opposite end of the attic to allow an air flow path through the attic for it to be most effective. It seems to me that the two would completement each other. The gable fan could be switched on and off using a thermostat mounted in the attic space to help save energy. With both fans, the volume of air required for effective cooling should be professionally determined; and when comparing quotes make sure that they are the same CFM fans since smaller fans = smaller price = smaller cooling and vise versa.

  • Bill says:

    NOTE from Todd: I’m not going to delete this comment, however, I do believe the commenter didn’t really read this article. I NEVER suggested running an attic fan while running A/C. Read this comment with a grain of salt.

    DO NOT USE POWER VENTILATION IN ATTICS> PERIOD!!!!!

    Whole house fans are helpful in cool climates. DO NOT RUN WHOLE HOUSE FANS WITH THE AC ON!!

    OMG!!! This is just the sort of (well meaning but) misinformation that is rampant. I know this is going to sound completely insane to most people. I will be happy to go on and on about my qualifications to make this claim if you like.

    Why?? You can not create positive pressures without creating negative pressures. When you are mechanically pulling air through your attic, you are creating a situation where the pressure inside your attic is lower than the inside of your home. Conditioned air will be drawn out of your home into the attic through cracks, exhaust fans, attic access doors and stairs, around the edges of your cieling, and wall opening where light switches and electrical outlets are located. Now, you have a lower presure inside your home than outdoors. The cool air that left your home for the attic will now be replaced by unconditioned air from outside. Thia air will be drawn in around the cracks in windows and door, ect.

    Bottom line. If you want to cook your atic with your AC system and then add the additional load fromoutside infiltration, go ahead. And to add insult to injury, you are using (waisting) additional energy to operate the attic fan that is causing this mess!

    So, what is the answer?? Natural ventilation. Vents in your boxing coupled with ridge vents. Oh, and one more thimg. I read that ridge vents do not work because hot air rises and when the air hits the vent, it will not move sideways and slightly downward. That is not true either. Air that is heated expands. When air expands in an enclosed space, pressure will ride. The rise in pressure will force the air out of the ridge vent with no problem.

    You may wan to check this website and others to verify my claim.

    http://www.energystar.gov/index.cfm?c=diy.diy_attic_ventilation

    • Todd says:

      @ Bill – I think you completely mis-understood this article. I NEVER suggested running AC and any type of attic fans. What I suggested was using a whole house fan when you’re NOT using A/C. These fans are used here in New England with very good results as a way to pull cool outside air into the home. Proper ridge vents and soffit vents are absolutely necessary and I completely recommend them. I hope you’ll go back and re-read my information and correct your statements.

  • Bill says:

    Hi Todd,

    My intent was NOT to disagree with you on whole house fans. In cooler climates, they make Perfect Sense. Here in the South, we usually use economizers to pull fresh cooler outdoor air in and distribute it during cool weather. This is especially beneficial in places like restraunts that have a lot of internal heat loads in cool weather. In effect, what you arte talking about is free cooling. That is great!!

    The main point of my comments was to stimulate conversations on mechanical attic ventilation pros and cons. Sorry for the confusion!

  • Jordan says:

    We live in Riverside, California and it gets pretty hot here. Would attic gable fans be better for removing the hot air from the attic? Or, would using a whole house fan be a better solution? Does the whole house fan work well when the temperature is hotter outside than in? Thanks.

  • Jordan says:

    thanks for your help

  • Jordan says:

    Todd, thanks for the help.
    Could you tell me how many gable attic fans should be used per how many sq ft of attic space we have?

  • Jordan says:

    How many gable attic fans should be used per how many sq ft of attic space we have?

  • bill says:

    Can some one help me out?
    I want to install a whole house fan (had one before)
    there is no clean space in my attic for it. I have recessed lights, HVAC, and fire system in the way. the one area I did actually want to install it, I cant get into that area of the attic due to the roof line cutting off the area. I know there is space up there, it is just sealed off due to changing roof peaks.

    So I ask, can one of these be installed without access to the area above. Basically, cut the dry wall out, lift it up in there, and install from inside the house? I know it sounds dumb. I really wanted it in thie one area.

    2, the only area up there I could use, is the attic door itself. can the attic door be the whole house fan, and double as the attic door? I dont go up there for anything, but one day the AC might need service.

    • Todd says:

      @ Bill – When was your house built? Today all areas of attics must be accessible for future maintenance and for fire access. If it were me I’d be half tempted to cut an access into that area, climb up there and see if there is a way to cut another access from that space into the adjoining accessible attic space. I myself would not install it in your current ladder location. Good luck.

  • AirCoolCalifornia says:

    The Whole house fans could be actually a very good suplement to a HVAC system to help you save on your electricity bill as well!

  • Donna says:

    I am considering installing a Whole House Fan in my auto inspection shop. What is the difference between a Whole House Fan and a Exhaust Fan? With the cars running my shop gets over 120 degrees in summer. I wanted to create a breeze and pull out some of the heat from the cars. My shop is 30′ x 21′ x 12′ tall. It is built inside a metal building twice the size of my shop. I have a 10′ x 10′ garage door that remains open. Do you think a whole house fan would benefit me? I would install in on my celing with the air venting to the unused space in the building. Thanks for your response!

    • Todd says:

      Donna – Whole house fans are really made for “houses” and not a commercial application. Frankly most states have pretty strict guidelines on both exhaust and fresh air intakes for commercial buildings that have any dangerous fumes (which an auto inspection facility would qualify for). I recommends going with a commercial exhaust system that incorporates fresh air.

  • Emily says:

    Can some one help me out?
    I want to install a whole house fan (had one before)
    there is no clean space in my attic for it. I have recessed lights, HVAC, and fire system in the way. the one area I did actually want to install it, I cant get into that area of the attic due to the roof line cutting off the area. I know there is space up there, it is just sealed off due to changing roof peaks.

    So I ask, can one of these be installed without access to the area above. Basically, cut the dry wall out, lift it up in there, and install from inside the house? I know it sounds dumb. I really wanted it in thie one area.

    2, the only area up there I could use, is the attic door itself. can the attic door be the whole house fan, and double as the attic door? I dont go up there for anything, but one day the AC might need service.

    • Todd says:

      Emily – Honestly it sounds like you’ve got a tough situation. First of all I would NOT recommend installing it into the only access point you have. That access is important for both servicing your HVAC and allowing access in case of a fire. Also, I wouldn’t recommend the other area unless you know it has sufficient venting to handle the pressure from the fan.

  • DeeJay says:

    We were just discussing the options of a whole house fan vs. a gable attic fan. Since we have some severe allergy sufferers in the house, I did not think the whole house fan made sense. I would like to cool the attic, since it does radiate a lot of heat into the upstairs bedrooms. However, we have a full ridge vent, and I was concerned that a gable fan would draw the air, and possibly rain, back through the ridge vent. What is your take on this?

    • Todd says:

      DeeJay- First off I don’t really like to see gable vents used with ridge vents because they can “short circuit” the function of the ridge vent. Properly installed ridge vents and soffit vents should allow enough air movement to significantly drop the temperatures in an attic. Often times we’ll see insufficient soffit venting which doesn’t allow sufficient air flow.

      Whole house fans work great but they will draw outdoor air in so that might be a problem for the allergies….

  • Michael says:

    I’ve wanted to install a whole house fan for quite a while. There are too many brands to choose from. Can you recommend a few that you like?

    Thanks

    • Todd says:

      Michael – There are quite a few good brands around. However, I suggest starting with your local electrical supply house (where your local electricians purchase materials) and ask them for references. They see all the brands and can give you great advice. I would also ask for a quote from an electrician and find out what he/she proposes.

  • ns says:

    Try one of the modern whole house fans, like airscape Or tamarack.
    Typically they are quieter, more efficient, and have automatically closing doors.

  • Dave says:

    Let’s clear up some information here about Whole House Fans… Everyone keeps mentioning that these fans are only helpful in moderate temperature locations. Not true!

    I like in the Midwest. Summers often include two months hovering around 100F!

    A friend of mine living in a vintage bungalow home showed me what an efficient Whole House Fan can do. The only thing he uses his AC for is to control humidity sometimes.

    It is common to have basements where I live. My friend draws his air from his nice cool basement. It’s like free AC!

    I just bought a 4500 sq ft two-story, with full basement. I will be installing a Whole House Fan and hope to limit my use of AC to very little.

    My basement is a full basement and keeps to a nice cool 68F even on days over 100F. I will be drawing air from the furthest location (in the basement) from my stairs through a basement window drawing from a shady part of the house.

    Be smart folks, and save yourself a fortune! With a little engineering you can eliminate those high summer energy bills almost completely!

    Last… Whole House Fans can also help keep upper floors cool when your AC below isn’t adequate. You have to be smart about how much pressure you are drawing, but even a small pressure will help add cooler air upstairs without adding a window unit. In order to not be wasteful, you must make sure your vented air source going in to your house is relatively cool. You don’t want to be trading cool air for warm air!

  • robert says:

    I need advice from anyone who REALLY knows a lot about my problem, AND feels that they can give me SOLID advice that I can rely on. When referencing this “blog entry” please mention “ROBERT” in your reply, so that I can quickly locate your comments. Thanx

    I live on the highest (3rd floor) level of a condo building. I have the 3rd floor AND the attic, triangular-shaped like the letter A. I have a non-working attic gable-mounted roof fan, which I’m considering replacing. The highest CFM that I see on the market is 1600 cfm. Is there any other HIGHER cfm Gable-Mounted fan with a thermostat?

    Secondly, it gets extremely hot in my 3rd floor. I’m very interested in installing a Whole House Fan, but the smallest one I found is 4500 cfm. My square area of my home is roughly 1300 sq. ft., or so.

    Here’s the BIG question for the expert(s): If I install a Whole House Fan of 4500 cfm, and replace my non-working attic fan with the 1600 cfm Gable mounted fan, then WILL THAT BE SUFFICIENT to move the hot air out of my attic AND cool down my 3rd floor and attic?
    I have approx. 7 openings/vents in my attic, but most of them are only 12″x12″ vents/openings. The only biggest vent/opening is one, 16″x16″ just for one Gable-mounted attic fan.

    I understand that 4500 cfm coming from the hallway into the attic is 3-times more pressure coming into the attic than what’s coming out of the attic (1600 cfm), BUT I have 5-6 other vents for air to come out of them: so would the excess 2900 cfm be able to get out of the rest of the vents of the attic?
    If not, then what do you suggest? Are there any smaller Whole House Fans, less than 4500 cfm? Is it really worth getting a smaller fan: because it may not cool my place with as forceful “wind-power” as a 4500 cfm fan? Are there smaller gable fans that will fit the 12″x12″ openings that I have? And what is the strongest fans (in cfm) that fit those dimentions?

    When answering, please provide as much information as possible: SKU numbers, full barcodes, manufacturer names and complete title of fan(s). Thanx Aug 27, 2010

    • Todd says:

      Robert – I wouldn’t consider myself an HVAC expert so the following are just my thoughts on the subject.

      1. Whole house fans work really good if/when there is cooler air outside which can be drawn into windows. If the air outside is hot the whole house fan will do little to cool things down.

      2. Have you considered evaluating your current insulation system and determining if more/better insulation in the walls or attic might be a more effective solution?

      3. Whole house fans can actually work fine without a powered gable vent. If there is sufficient vented space (gable vents, soffit vents, ridge vents) then the differential pressure caused by the fan will force that air out.

      4. My feeling is that the gable vent is not likely working well BECAUSE you have other vents.

  • Tino says:

    I am converting a 24′x30′ barn with 10′ walls and 4′ high roof into living space. I already have an 18 x 29 opening. I am considering increasing the opening to 29 x 29 for an 24″ 45 CFM fan but I think it might be overkill. I am considering and 18″ exhuast fan (TPI 18″ Shutter Mounted Direct Drive Exhaust Fan, 3 Speed, 1/8 HP)but I am not sure of the difference between and enhaust fan and a regular attic fan?

    Tino

  • Ty F says:

    Hello Todd I need help with this attic fan install, I live in Ohio my house is a Bungalow and my second floor is my master suite, the roof line is basically my ceiling except in the hall, I have to access panels to crawls spaces on the front part of the house and rear, where my gable vents are, u can’t get to them because there’s only about 12 inches from the ceiling to the roof peck in the hall way. what is my best bet for an attic far? I’m thinking roof mount?

    • Todd says:

      I’ve never done one with this little ‘attic’ space. I’m thinking you’ll need a special type that can go on the roof. Frankly I think you should stop by an electrical supply shop and ask them for a recommendation.

  • Rich says:

    Hi
    My roof mounted attic fan stopped working. If I were to relace it with a gable mounted fan do I have to cover up the hole in the roof?
    Wouldn’t I just be sucking hot air thru it. Or should I replace it and could or should I add a gable mounted fan

  • We are looking for a COMPLETE solar powered whole house fan. (Not an attic vent fan that sits on the roof top). I am talking about a solar powered whole house fan that is between your ceiling and attic. I’d love to get one of these to eliminate ANY electric usage if possible. (we are converting to fully green power).

    If you know of anything I’d appreciate it.

  • Roger says:

    Todd, I had a gable fan in my old house. When I had my new roof installed in this home the roofer said that the fan wasn’t necessary since I was getting a full ridge vent installed.
    He mentioned that the fan would “short circuit” the natural ventilation. What do you think about that reasoning?

    BTW my wife and I don’t keep the house very cool(to some). I recently installed another layer of fiberglass in the attic and it has helped a lot. It is rare for my interior to get above 80 deg. even when it’s approaching 100 outside.
    When we do run the A/C it is only set at 78 deg.

    • Todd says:

      Your roofer was correct. Gable fans/vents really shouldn’t be used in conjunction with ridge vents. I do see some people install a roof vent occasionally on a house with ridge vents…this is set up to help cool the attic even more if temperatures get too hot.

  • Phillip says:

    This was actually the perfect article and precisely what I thought. I’m doing some research into low cost/efficient ways to keep the house cool, since Northern California regularly has days in the 100s. Our attic is extremely hot/swealtering even on 80 degree days, and while we have lots of attic ventilation (new house), it’s mostly little holes near the eves and a decent sized gable vent. Since heat rises, and most the holes are guarded by the roof from wind, I’m thinking there’s a lack of wind movement creating the extreme heat up there.

    With all that being saida few questions: Do gable attic fans blow cool air in, or hot air out? How efficient are they? Some sites say they suck cool air from the house, others say so long as you have insulation it should keep energy costs down by keeping the house cooler. Lastly, what’s the difference between an attic fan and basically a regular fan? I understand most are better “fitted” to the vent than a regular fan, but it sounds like you could easily modify one yourself, and if the attic is regularly hot even at night, why wouldn’t you want the thing running 24/7 but on a heat timer instead?

    Lots of questions, but most seem to gloss over the details.

    Thanks!

    • Todd says:

      Philip, gable fans blow hot air out. Whole house fans suck hot air from the house and push it to the attic, where it exhausts from the attic due to positive pressure. Both fans are heavy duty fans and built for this application.

  • Sally G says:

    Todd,
    I just found this page after someone mentioned “whole-house fan” at a BBQ this weekend; I had not heard of them before and was looking to understand the difference between them and an attic fan.
    My parents still live in the ranch house in which I grew up in northern New Jersey (built ~1950; attic partially opened to create an office overlooking a double-story family room); all my life we have cooled in the summer by turning on the attic fan at night/early morning to bring in the cool air from outside, shutting it and all windows when the temperature rose to be hotter outside than inside. In the past couple of decades, my parents have gotten a couple of single-room air conditioners (upstairs office and their bedroom) to supplement this system on the hottest days—we all still prefer fresh air when reasonably cool.
    This year, the moving cool air and noise of the AC has begun to bother my father, who insists on turning off the air conditioners (he has dementia). Would a whole-house fan be suitable? It seems to me that the attic fan is not drawing as well as it used to do—any thoughts on why that might be? Overall recommendations?
    Thanks for any leads on improving the cooling situation for my parents (and often me).

    • Todd says:

      Sally, A whole house fan may help. It seems like the existing attic fan is doing what you want to some extent. However, attic fans are not really designed to pull that much air. I’d get an electrician to look at it and give you a recommendation. Good luck.

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