We get a lot of questions about fans, and one of the ones we hear most from homeowners is:
What’s the difference between a whole-house fan and an attic fan?
This is not only a frequent question, but a very smart one as well since they can both be brilliantly effective ways to cool your home and save big money on utility bills.
Despite their similarities, though, attic fans and whole house fans are very different in what they do and in how they work, so let’s look in more detail at the differences between the two.
So, What’s the Difference?
Both whole house fans and attic fans are mounted at the top of your house, both are meant to keep your house cooler, and both can save big money on energy bills, but they are different in how they go about these things.
What Is a Whole House Fan?
A whole house fan is an electric fan usually mounted in the top ceiling – that is, the ceiling that is right below the attic – and designed to pull warm, stale air throughout the house up and out. To facilitate this you would leave windows, or even doors, open in various places in the house, letting outside air come in to replace the hot air the whole house fan is exhausting.
This means that it is best to use a whole house fan only when the air outside is actually cooler – and hopefully quite a bit cooler – than the air in your house, so they are typically run in the cool of the evening, at night and in the cooler morning hours, and then shut off when the temperature outside begins to rise.
When this happens – that is, when the outside temperature gets high and the fan is shut off – you would also want to close down those windows and doors, and probably all windows and doors, to seal the new, fresh, and cool air inside during the hot day.
Whole house fans are remarkably efficient and effective, and before air conditioners became so prevalent they were the main method of really cooling an entire house’s interior. These days they are much less common (though not less effective), although they are gaining popularity among smart homeowners as either a stand-alone system or a way to support air conditioning.
Used in this second way, not only do whole house fans allow your AC to work much less, and therefore save you big money on utility bills, but they also let you enjoy fresher air much of the day than you get from ACs alone.
What Is an Attic Fan?
Attic fans are also meant to keep your home cooler and are even more popular ways to support your air conditioner and keep utility bills down.
But instead of pulling warm, stale air out of the house’s interior, like a whole house fan, the attic fan pulls super-heated air from just the attic’s interior.
Attic air, and the roof’s very structure, can get incredibly hot during the day – up to 160 degrees or more – which can not only continuously heat the entire house from above, and make your air conditioner have to work much, much harder, but can also be damaging to the structure of your roof and even your house.
So people often use attic fans to cool things down. These are also electric fans, like whole-house fans, but instead of mounting in the upper ceiling they mount in the attic – either through the roof or through a dormer wall.
An attic fan’s thermostat will determine when the attic and its air is getting too hot, and turn the fan on, pushing the very hot air out and pulling air in from the outside. This outside air is also hot, but not nearly as hot as the attic air, and the goal of an attic fan is to approximately match the attic temperature with the outside ambient temperature.
So an attic fan can also keep your home cooler, but more indirectly. It is not designed to circulate cooler air through the house as a whole house fan does, but instead to circulate cooler air just through the attic space.
As such, an attic fan won’t significantly drop the house’s overall temperature – it can, though, decrease temperatures on the upper floor somewhat
Instead, it is most often used to keep the attic and roof cooler, prevent them from making the house below even hotter, and thus support and take some of the load off of your house’s air conditioners.
Whole House Fans and Attic Fans – Advantages & Disadvantages
Now that you know some of the basic similarities and differences between these two kinds of fans, you may still be wondering which might be best to use, so let’s break down some of the good and bad points of each.
Whole House Fans Pros & Cons
| ✅ Pros | ❌ Cons |
|---|---|
| Very effective and fast whole-house cooling | Temperatures will begin to rise during the hottest times of the day |
| Much cheaper to run than air conditioning | Not best for very humid climates or days |
| Nice, fresh, circulating air | Older whole house fans can be noisy |
| No refrigerants | Can let in cold air during winter months, and should be covered or insulated |
| Quieter than most AC systems | |
| Excellent support for AC systems | |
| Low energy usage |
Attic Fans Pros & Cons
| ✅ Pros | ❌ Cons |
|---|---|
| Significantly reduce the work of an air conditioner | themselves, don’t reduce temperature in the house significantly |
| Can protect your attic and house structure from heat damage | Without sufficient attic ventilation, can begin exhausting air conditioned air from below |
| Less expensive to purchase than whole house fans | Can let in cold air during winter months, and should be covered or insulated |
| Easier and cheaper to install than whole house fans | |
| Very quiet running | |
| Work in a wider variety of climates and days, including high humidity | |
| Can be solar powered |
Download this FREE cheat sheet to find 28 tricks that can help you save on your electricity and heating bill each month.
Click here to get a FREE Cheat-SheatSo, Which is Best for You – a Whole House Fan or an Attic Fan?
Attic Fans are these days at least, a much more popular option. They cost a lot less than whole house fans, are easier and less expensive to install, and once installed do a brilliant job in their limited but very important role.
For keeping the attic cool, protecting the roof’s and house’s structure, significantly reducing the load on your air conditioner – whether central air or individual window-mount or portable ACs – and saving big money, a good attic fan is highly recommended to any homeowner.
Whole House Fans are not as universally recommendable. They are more expensive to buy and harder and more expensive to install, they only work in drier climates and become less effective when humidity rises.
All that said, a good and properly installed whole-house fan can be, in the right climates, a fantastic way to cool and refresh your whole house. Although not common, some people still use them instead of air conditioning, and in conjunction with AC, they work fantastically well, offering your air con a cooler starting point, saving really big money on utility bills, and making the whole house’s air fresher and nicer.
Our bottom line is that an attic fan is an almost mandatory purchase – even if you live in cooler areas, your attic will still get dangerously hot in summer months, and affect the temperature of your whole house. And if you are in hotter areas the money your new attic fan will save you is nothing short of astonishing!
And for cooler, drier climates, or hotter, drier climates in conjunction with air conditioning, a whole house fan is a smart, efficient way to also get big savings in utility bills and energy usage, and makes the whole house delightfully fresh and pleasant. Not for everybody, but in the right house they are always well worth the money.
Who Makes the Best Attic Fans and Whole House Fans?
While this is not a buyer’s guide, with extensive recommendations and reviews, I thought it would be nice to close with a simple list of a few whole house fans and attic fans we here at Know the Flo love and recommend.
The Best Attic Fans
Here are four excellent choices for attic fans, but I would definitely recommend any of the products from a couple of really great companies – specifically, QuietCool and Broan NuTone.
QuietCool Attic Gable Fan with Thermostat (AFG PRO-2.0)
Broan 355BK Roof Mount Attic Ventilator for Home
QuietCool 40 Watt Solar Powered Gable Mount Attic Fan
Remington Solar 40-Watt Solar Attic Fan (BDB) with Thermostat/Humidistat/adapter
The Best Whole House Fans
In addition to the products below, I would also recommend you check out the product pages from a couple of our favorite companies – QuietCool and Centric Air.
Tamarack Technologies HV1000 R38 Ductless Whole House Fan with Insulated Doors
QuietCool QC ES-5400 Energy Saver Fan Classic Line Model
QA-Deluxe 6500(R2T) Energy Efficient Whole House Fan with Timer & Temp Control
Download this FREE cheat sheet to find 28 tricks that can help you save on your electricity and heating bill each month.
Click here to get a FREE Cheat-Sheat
