Pros and cons of whole-house fan

As the summer heats up, consider a whole-house fan as an alternative to costly (and energy-hogging) air conditioning.

The fans exhaust warm, stale and possibly contaminated air through louvered shutters, usually on the ceiling at a high point in the house. Fresh air is pulled in through open windows and doors. A wall switch, switch/timer or automatic thermostat controls the fan.

Whole-house fans come in two types: ceiling-mounted or attic-mounted. Ceiling mounts, installed directly above louvers, draw air into the attic, where it is forced out through vents in the eaves, roof or gables. Attic mounts, installed in the roof or exterior wall of the attic, blow air directly out.

Both types are available as direct-drive, with the fan blade attached to the motor, and belt-drive, with the motor mounted to the side to rotate the blade with a pulley and belt. Direct-drives tend to be noisier and less powerful, but less expensive.

Reasons for a whole-house fan:

• If you don't have air conditioning, a whole-house fan creates a cooling indoor breeze.

• If you do have air conditioning, the fan will suffice on all but the hottest days, reducing energy costs. Running a fan before turning on air conditioning also will draw heat out, allowing the home to cool more quickly.

• Regularly replacing house air can reduce airborne hazards and nuisances such as radon, formaldehyde, carbon monoxide, cooking and pet odors.

Reasons against:

• If you live in an extremely humid, dusty or pollen-laden area, a fan brings these problems indoors -- a bad idea for allergy sufferers.

• It's not effective in certain climates. A fan works best when outside night temperatures dip at least five degrees lower than the desired indoor temperature. Ten or more degrees is better.

• It hums while running. Some folks say the droning drives them nuts.

• Ceiling louvers clash with some people's sense of decor.

• It could be redundant. Some central air-conditioning systems have a ventilation mode that accomplishes the same thing as a whole-house fan. But don't confuse this with the fan setting that recirculates air without exhausting it.

Selection:

Noise.

Attic-mounted fans are quieter because they're farther away from the living area.

Speeds and controls.

Two-speed fans allow a high speed for quick cooling or exhausting fumes, and a slower, quieter speed for continuous operation.

Ventilation.

Not all homes have adequate attic ventilation for ceiling-mounted units. Hot air must flow out of the house through screened vents on the roof, at the gable ends, along the eaves or all of the above.

For more information on these fans and how to choose the proper size and install it, see the

.

-- Homes & Gardens of the Northwest staff

Photo: yurmary / Adobe Stock

Whole-house and attic fans are two ventilation systems with common goals in mind, cool the home and help lower your energy bill. But each system takes a different approach to cool the home. Learn more about the pros and cons of each, right here.

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What’s the Difference Between Whole-House Fans and Attic Fans?

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The most noticeable major difference between whole-house fans and attics starts with their name. One focuses on attics, while the other focuses on the entire house. Yet, both work to cool the entire house.

Whole-House Fans

Whole-house fans use a system to cool the home when the temperature outside is cooler than the inside. When the outdoor temperature reaches a certain level, typically between 70 and 80 degrees Fahrenheit, the whole-house fan will turn on. The fan pulls warm air to the top level of the home and blows it into the attic.

For whole-house fans to work properly, you’ll need to keep downstairs windows cracked to let in the cooler air from outside. The cooler air then reduces the temperature throughout the home. These fans do need extra ventilation in the attic though, typically in the form of roof or gable vents.

Attic Fans

Rather than focusing on ventilating the entire house, attic fans instead focus on cooling the attic, which in turn cools off the rest of the home. Attic fans use a roof or gable vent to move warm air out of the home when the attic hits a preset temperature. Whether you choose to use a gable or roof vent makes no difference, as they both perform equally.

Whole-House Fans vs. Attic Fans: Which Is Better?

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If whole-house fans and attic fans are trying to accomplish the same goal, that must mean one is better than the other, right? That’s not entirely true; it’s more like one is better for certain people while the other fills in the gaps.

Cost

The cost to install an attic fan is around $600 on average, including installation and equipment. Compared to the cost to install a whole-house fan, which comes in at $850 normally.

Lower installation cost: Attic fan

Climate

Attic fans work better in any given climate, as they simply focus on removing hot air from the attic and home. But they only cool the areas of the home directly underneath the attic, so it may feel pointless in two-story homes.

Whole-house fans work well in cool climates and can drastically reduce the need for an air conditioner in these climates. But this typically means they don’t work well in humid, warm climates.

Most adaptive to any climate: Attic fans

Best for cool climates: Whole-house fans

DIY Installation

When it comes to installing attic and whole-house fans, there is almost no competition on which is easier. Attic fans simply require less time and work to put up. Though, this doesn’t mean it’s not a hard task in itself. If you’re unsure about the task at hand, you can always hire an attic and whole-house fan installer near you.

Easiest to DIY: Attic fans

Repairs and Maintenance

The cost to repair attic fans is around $300 on average. This just so happens to line up with the cost to repair whole-house fans, at around $300. Attic fans are more likely to have faulty wiring and broken thermostats, while whole-house fans are more likely to see blown fuses, as well as faulty wiring.

Easiest to maintain: Tie

Energy Efficiency

Whole-house fans are excellent competitors with central AC units, using only 10% to 15% of the energy that AC units need. Though this only applies to cooler climates, as in humid, warm climates, the whole-house fan may end up making your AC work harder. They do work fast though, being able to cool a house in as little as an hour.

Attic fans tend to also cool the home while still only using a fraction of the energy needed that an AC unit does. The only issue with attic fans and energy efficiency is that it often causes the attic to cool too often, so the attic fan ends up ventilating out cool air which may be needed to cool the home.

Most energy-efficient: Whole-house fan

ROI and Resale Value

Attic fans don’t really offer any resale value or return on investment. Attic fans have a higher operating cost than whole-house systems, making them burn more money than anything else. 

Whereas whole-house fans have a significant ROI and can pay for themselves in as little as three years. Those living in cooler climates and looking to buy a house may be excited to learn that there’s a whole-house fan in the home. This does typically lead to an increase in the resale value of the home.

Best for added value: Whole-house fan

Which Is Best for Your Home?

Photo: alhim / Adobe Stock

You should choose an attic fan if:

• You have an AC system that runs decently often
• You live in a warm, humid climate
• You are working with a lower installation budget
• You are looking to tackle this project yourself

You should aim for whole-house fans if:

• You don’t necessarily need an AC unit
• You live in a cool, dry climate
• You’re looking to maximize ROI and resale
• You want to increase energy efficiency

Though, hiring an attic or whole house installation company may be able to tell you which is right for your specific home.

Attic Fans vs. Whole-House Fans vs. Air Conditioners

Attic fans are great compliments to air conditioners and can work together to cool the house in the most efficient way possible. But in the right climate, whole-house fans will work just as well as an air conditioner to bring down the temperature in the house. Whereas air conditioners will work to cool the house, regardless of climate.