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Guide to Whole House Fans

Guide To Whole House Fans

When it comes to energy consumption, our home’s heating and cooling take up a pretty big piece of the pie.

According to the US Energy Information Administration, more than half of a household’s energy consumption each year is spent on air conditioning and space heating, signaling a need for an alternative that doesn’t chew so much power, like whole house fans.

What are whole house fans and how do they work?

A whole house fan is made up of large exhaust fans that draw out the stale interior air through vents and pull fresh, cool outdoor air in.

They’re a low energy option for keeping the inside of your home comfortable and come with plenty of other benefits if you’re looking for a new cooling system.

Considering how much energy heating and cooling systems use in our home, deciding to switch to something more energy conscious is a smart move.

We’re going to look at the basics of whole house fans, their pros and cons, and how to get them up and running in your home, so you can decide whether this green cooling option is the way to go for your household.


What Does a Whole House Fan Do?

What Does A Whole House Fan Do?

Whole house fans are one of the most straightforward cooling options for the home, basically working with a large scale fan that delivers fresh air to the whole house.

Unlike an attic fan, a whole house fan draws the air up and out of the living spaces and into the ceiling. From here, it’s extracted outside through vents found in the roof, commonly referred to as soffit vents or ridge vents.

The whole house fan system works like a vacuum effect as it pulls out the hot air and then sucks the cool air into the house.

This air is pulled in by strategically placed vents in the lower-lying areas of the home, like through windows or vents.

The fan itself is found at a high point of the house, usually the highest ceiling in your home and the most central one, and from these two separate areas the system works together.

There are some basics your home needs to have this system work, with the most important being operable windows and the ability for good airflow to come through near the central fan.

With these in place, the hot air will be quickly dispersed through the upper vents from the ceiling.

Keeping the windows closed while the fan is on will also keep temperatures down as it circulates the cool air that’s been pulled from outside, which is usually much cooler than inside the home.

How Effective Are Whole House Fans?

A whole house fan works on an air change rate which is a measure of the air volume that’s being added or removed from a house, then divided by the volume of the actual space.

When it comes to these specific types of fans, they should be operating at 30 to 60 changes per hour to be effective.

Some factors will impact how effective your whole house fan is, and a professional will be able to assess your home before you go ahead with the installation.

When looking at the air change rate specifically, this will depend on the climate you live in and how much you’ll rely on the fan for cooling and ventilation.

A whole house fan will be most effective when the air outside is cooler than the air inside. It also prefers homes with lower humidity so it’s better for people living in dry and hot climates.

As these fans are pulling in air from outside, the air must be cooler than the interior. Otherwise, it won’t do its job and will only be delivering more of a light breeze and ventilation inside the house.

Other things that are important to note are the layout of your house’s interior, the outside temperature, construction and materials used to build the home, and whether windows, vents, and other sources of ventilation are available.

The more things you have in your favor, the better these fans will work, but most modern homes will find the installation of a whole house fan to be invaluable.

Are They a Smart Idea for Going Green?

One of the biggest selling points of whole house fans is their green factor, and they’re often touted as the modern solution to reducing household energy use.

If you’re looking to reduce your cooling costs and your home fits all of the requirements to make these fans their most efficient, you’ll be pleased to know they exceed all other options when it comes to cost and energy usage.

To understand how much energy a whole house fan uses compared to other cooling options, it’s best to compare them by their running costs.

During the warmer season in a standard home, a 2-ton air conditioner costs around 20c per hour of run time and a large 18,000 Btu/h window unit air conditioning system costs around 17c per hour to operate.

By comparison, the whole house fan is significantly cheaper. Having one of these fans operating at home using a standard motor sized ¼ or ½ horsepower motor costs between 1c and 5c per hour.

Those costs are to cool your entire home as well, and not just for one bedroom, so you can see how dramatic the savings are.

In addition to saving money, these reduced costs also translate to saving energy and mean a house can significantly decrease its carbon footprint each year.

For a home looking to go green by making some simple changes, there’s no easier way than tackling your heating and cooling costs, and a whole house fan is the most effective way to do this.

The Benefits of Using a Whole House Fan

The Benefits Of Using A Whole House Fan

There are plenty of benefits available for households who make the switch to a whole house fan. If you’ve been weighing up your options for a new cooling system, check out the advantages that this particular one has to offer.

Energy efficient

A whole house fan uses just a fraction of energy that other systems do and it gets it cool air from outside. As far as natural cooling goes, this is the friendliest one you can get for the environment.

Low cost

All parts of a whole house fan are cheap compared to other cooling systems including purchasing the unit, having it installed, and the ongoing running costs.

Fast acting

The cooling effects of a whole house fan can be felt in minutes making them one of the fastest cooling systems around.

As they draw in air from outside and blow it straight into the home, you’ll notice an instant improvement in temperature when you turn them on.

Reduced need for air conditioning

These fans can be used most of the time to keep air flowing through the house, and even when it’s hot outside they’ll do a great job of keeping it cool.

There’s a reduced need to use the air conditioner so you only have to rely on it if temperatures soar and the whole house fan can’t make an impact.

Fresh air

A whole house fan cools your house by using outdoor air which means the stale indoor air is sucked out at the same time. This results in fresher air indoors and greater ventilation which also removes odors.

Potential Drawbacks of Whole House Fans

Potential Drawbacks Of Whole House Fans

Whole house fans come with a lot of advantages, but we should also look at where they fall short. Consider these potential drawbacks if you’re thinking of having this system installed at home to see if they’re the right fit for you.


These fans operate more loudly than standard ceiling fans and air conditioners. If placed in a central area near bedrooms they may affect your quality of sleep as they run during the night.

Energy loss in winter

During winter when we want to conserve indoor energy, it can be lost through a whole house fan if you don’t have. Any heated room will lose air into the attic so you may prefer an insulated whole house fan that will cost a little extra.


Because a whole house fan is drawing in fresh air from outside, it’s also bringing in potential allergens. Dust and pollen might be drawn into the home that wouldn’t otherwise be there, so you might have to install a purifier if this is an issue.


These systems offer no purifying or dehumidifying properties like air conditioners so they do lose some points here. For homes that live in humid areas they tend to work less effectively, so consider your climate before you make a decision.

Not as cooling

A whole house fan is only capable of cooling the inside of your house to the temperature outside, and nothing less. If it’s hot outside this is what you can expect inside, so you’ll probably also want an air conditioner if you live in warmer climates.

Choosing the Right Whole House Fan For Your Home

Choosing The Right Whole House Fan For Your Home

Once you’ve decided to install a whole house fan, you’ll need to be sure you choose one that’s suited to your home. A licensed professional will be able to guide you towards the most suitable options but you’ll have to decide between a few determining factors to see which is best.

Fan speed

The most popular choices for fan speed are either two-speed or variable. A two-speed fan operates on high when it’s first turned on to get the air moving quickly and then can be turned down throughout the day for gentle circulation. A variable-speed fan is more flexible and can be adjusted to any speed you require.


How you turn the system on and off can be customized to your home. There are wall switches, pulls, rotary wall switches, and timers available to choose from, each with their own pros and cons.


The number and type of louvers in the fan system can vary, but in most cases, they’ll operate automatically whenever you turn it on.

Some have the option to use motorized dampers that regulate the flow of air, but they’re not usually needed if the louvers are operating as they should be.

Motor mounts

There are two types of units classified by their motor mounts. Direct drive units use fan blades attached to the motor shaft and these are cheaper to purchase, but usually make more noise.

Belt-driven units are more expensive but make a lot less noise because the motor is driving a larger fan with more blades that are spread out.

How to Install Whole House Fans

Whole house fans are not something that can be installed by the home handyman, so it’s best to call in the professionals.

Many parts come with the installation including measuring assessing the space and installing the hardware and circuit wiring, therefore a licensed professional is the smartest approach.

A professional installer will come to your house to assess the building first, as they’ll need to ensure there’s enough attic ventilation.

If not, they’ll increase this to the correct amount by installing vents, windows, and other spaces where the air can move.

The goal is to have up to four times the usual vents that an attic has, translating to around one square foot for every 750 cubic feet of a fan’s power.

Another important thing they’ll look at is a fan’s winter cover which is used for homes that want to use either air conditioning or a whole house fan.

As you can’t use both at the same time, the fan must be sealed tightly when it’s not in use, and a sealed, hinged door is the best method. These can also be built when you have the system installed, depending on whether it’s necessary or not.

Once the installation is done, a professional will also need to assess the safety of operating the fan.

Due to the large size of the van and its powerful suction, it needs to have adequate ventilation otherwise it can lead to serious consequences like pulling carbon monoxide into the home or creating a backdraft in the furnace or water heater.

This isn’t a risk you want to take in your family home, so it should never be attempted without a licensed professional.

A Green Option for Keeping Cool

A Green Option For Keeping Cool

As individuals, the best thing we can do for the planet is to look at our own households and see where we can make a difference. As one of the biggest energy consumers we own, our heating and cooling systems should be first in line.

Whole house fans are a simple and affordable option that can cut energy bills and reduce our carbon footprint, so they’re well worth considering.

If your home ticks all of the boxes for suitability, there’s no reason to delay making the switch.

Whole house fans are easy to operate, make very little impact on the environment, save a lot of money, and bring fresh and cool hair into your house the natural way.

If you can make sacrifices on noise and maintenance that comes with these systems, the planet and your wallet will surely thank you for it.

Related Questions

Whole house fans are relatively new on the market when it comes to home cooling options, but they’re one that’s set to take off in popularity.

If you’re considering making the switch to a whole house fan but want to know more, we’ve answered some frequently asked questions to give you more of an understanding.

Can You Run a Whole House Fan at Night?

There’s no limit to when you can run a whole house fan, but one of the most optimal times is at night. These fans work best when the outdoor air is cooler than the air inside and nighttime is a prime example.

At night, these fans work at cooling the entire house down and replacing its air with the cold air from outside, so it’s at its most effective.

How Much Does a Whole House Fan Cost?

Just like all other heating and cooling systems, the costs for whole house fans vary depending on a few factors.

The size, power, and quality of the fan will impact its cost, as will the labor cost, so you can expect to pay anywhere between $700 to $3,000 depending on all of these factors.

Does a Whole House Fan Qualify for a Tax Credit?

The IRS may allow you to claim a tax credit on the installation and purchase of a whole house fan in some cases.

This tax credit is classed as an energy tax credit because of the energy efficiency of the system. Credits are usually capped at $50 per fan but will differ depending on how much it costs to purchase the fan system and have it installed.

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