Homeowner’s Guide To Box Fans

Updated: Nov. 23, 2023

Wondering what a box fan is, or how to use one more efficiently? Here's a handy resource for anyone hoping to beat the heat.

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Generations have relied on box fans to provide additional airflow during hot or humid weather. Ask anyone who grew up without air conditioning. Chances are, they carried a box fan from room to room all summer. Box fans are a great way to beat the heat, and affordable enough to fit within almost any budget.

What Is a Box Fan?

As the name suggests, a box fan’s blades are enclosed in a shallow square box, with grilles on the front and back to allow air to pass through. A box fan can be oval or round, although most manufacturers and consumers refer to those as “floor fans.”

Box fans do not oscillate, or rotate from side to side. While they can be placed in a window, they’re not specifically designed for it.

Some key considerations when shopping for box fans:

  • Size: Box fans range from 10 to 20 inches across. Larger fans move more air but may not fit in tight areas. The average box fan is 20 inches tall by 20 inches wide, and three to four inches deep. The actual width and height is often slightly larger than that, so keep that in mind when considering a fan for a tight space.
  • Airflow: Measured in cubic feet per minute (cfm), the higher a fan’s airflow, the more effectively it will cool. But too much airflow can disturb papers or other light objects. Manufacturers typically list only the highest cfm the fan can produce, usually between 1,400 and 2,400 cfm.
  • Variable speed: Some box fans feature multiple speed options, generating more or less airflow and noise.
  • Remote control: Fans with remotes let you start, stop or adjust the speed from a distance. This is particularly useful for reducing fan noise during a Zoom call.
  • Noise level: Fans generate noise from the airflow and their mechanical motion. Fans with a noise rating of 65 decibels (dB) or less are as loud as a typical conversation, while those closer to 30 dB equal a whisper.

Benefits of a Box Fan

Fans consume significantly less energy than an air conditioner, and their affordable price ($10 to $50) keeps them within most homeowners’ budgets. Unlike a permanently-installed ceiling fan, box fans are portable, so you can carry one to any part of your home, porch or patio. And you can take it with you when you move.

How To Use a Box Fan

Using a fan is straightforward, as long as you keep a few simple things in mind.

Box fan placement

The main consideration is airflow and safety. While fans are tested for stability, don’t press your luck. Place a box fan on a stable base where the cord won’t pose a tripping hazard.

Ideally, the fan will create a cross-breeze moving through the room. To maximize airflow, don’t set the front or back too close to a wall. Try to leave a gap equal to one fan blade length, or half the fan width. So a 20-inch fan would be at least 10 inches from the wall.

Cord safety

Box fans can operate with an extension cord, but it’s better to buy a fan with a cord long enough to reach a convenient wall outlet. Don’t place the cord in areas with high moisture, or where someone might trip over it.

Child and pet safety

Never place a box fans where a child or playful pet might tip it over. We couldn’t find any box fans that automatically turn off if tipped over, like many space heaters. But box fan bearings won’t generate heat if tipped over, so they won’t be a fire hazard.

The protective grille will keep children’s fingers out, but they won’t prevent a curious kid from sticking a pencil or toy into the path of the blades. Rounded corners and plastic enclosures make some box fans slightly less hazardous for toddlers who might tumble into them. But if your child or pet will be unattended even for a moment, always place the box fan out of reach.

Should a box fan run 24/7?

It can. But if you’re not in the room 24/7, what’s the point? Only run it when someone needs the cooling.

Like all machines with moving parts,  the bearings or motor will wear out at some point. But in theory a box fan should run reliably for years.

Box Fan Cleaning and Maintenance

There’s one common cleaning or maintenance task: Cleaning dust off the grille and blades. How often you need to do this depends on how often the fan runs, its location and the amount of dust and hair in the area.

To clean the fan:

  1. Turn off and unplug. If it’s battery-operated, remove the batteries.
  2. Remove the protective grille. Some box fans detach in the rear, others in the front. Yours may have a snap-on grille that pulls off, but most are secured with screws.
  3. Use a soft-bristled brush or a vacuum cleaner with a brush attachment to remove dust and debris from the fan blades, motor and grille surfaces.
  4. Wipe the fan blades with a cloth to remove any remaining dust or debris.
  5. Reattach the protective grille and connect the power.