What Is a Box Fan?

Box fans are among the cheapest and most widely sold household fans.

What is a box fan?

A box fan is a portable electric fan in a square housing, usually with a 20-inch blade, a speed switch on top and a grill on the front and back. It sits on a floor or table, or in a window, and blows air straight ahead without oscillating.

This article covers what box fans look like, what they are for, how they differ from other fans and how to use one safely.

What Does a Box Fan Look Like?

A box fan looks like a square box with a motor and fan blades inside, behind a plastic or steel grill.

The image above shows a typical box fan.

Box fans come in all kinds of colors but white is very popular.

Why Is It Called a Box Fan?

These fans are named for their box-like shape.

Most fans have simple names:

• Neck fans hang around your neck
• Ceiling fans go on the ceiling
• Tower fans look like miniature towers

Box fans are designed in a square box, which makes them easy to carry and store.

What Size Is a Box Fan?

Box fans come in different sizes to meet your needs. You may want a box fan just for yourself, for a small room, or even for industrial purposes.

Here is a quick table to show you a range of sizes:

Most standard box fans have a 20-inch blade. The housing is a little larger. Lasko and Air King list housings about 21 to 22.5 inches on each side and 4 to 6 inches deep.

Smaller personal box fans are also sold. Models sold as commercial or industrial grade are usually still 20 inches, with more steel in the build.

Personal box fans are much smaller and are made for a desk or table.

What Are Box Fans Made Of?

A box frame is made of a combination of plastic and metal parts.

The parts that make up a typical box fan include:

• Frame: the outer housing (steel on many 20-inch models, plastic on smaller ones)
• Fan blades: The parts inside the housing that spin to move air (metal or plastic)
• Motor: The engine of the fan, which is located in the middle or back of the body (made of metal)
• Guard/Grill: A metal or plastic screen that protects the fan blades from fingers, pets, and other objects

What Is the Back of a Box Fan Called?

There is no special name for the back of a box fan.

The backside of a box fan looks almost identical to the front of a box fan.

On closer inspection, you can see some slight differences in the protective grill. You’ll also notice the housing for the motor.

What Kind of Motor Is In a Box Fan?

Box fans typically use small AC induction motors. Air King, for example, lists a permanently lubricated permanent split capacitor motor for its 9723 box fan.

Induction motors work by using a rotating magnetic field to create an electric current in the rotor. This current then creates its own magnetic field, which turns the fan blades.

What Is the CFM of a Box Fan?

Makers list very different airflow figures for 20-inch box fans. Comfort Zone lists a maximum of 640 CFM for its CZ200A. Lasko lists up to 2,000 CFM for its Pro Power B20548. Air King lists 2,163 CFM on high, 1,900 on medium and 1,463 on low for its 9723.

CFM stands for Cubic Feet per Minute. CFM is the number of cubic feet of air per minute the fan moves.

A higher CFM figure means the fan moves more air. Published figures vary a lot between makers, so compare them with care.

What Is The Decibel Level of a Box Fan?

Makers rarely publish a decibel figure for box fans. The Lasko, Air King and Comfort Zone product pages checked for this article do not list one.

Decibels measure sound pressure level on a logarithmic scale, so a small change in the number is a large change in the amount of noise. OSHA notes that A-weighted decibels (dBA) closely match how loud a sound seems to the human ear.

Does a Box Fan Work in Very Hot Weather?

Fans do not cool the air. They cool people by moving air across the skin, which only works when that air is cooler than the body. New York State health guidance says that when indoor air is hotter than about 95 F, a fan may cause the body to gain heat instead of lose it. The CDC sets a lower line and says to use fans only when indoor temperatures are below 90 F. Above that, use air conditioning or go somewhere cooler.

What Is a Box Fan For?

You can use a box fan for a variety of purposes.

Box fan uses:

• Blowing air into or pulling air out of a room when set in a window (check the maker allows window use)
• Creating white noise to help you sleep, study, or meditate
• Circulating air around a space (like a grow room)
• Boosting the airflow from an air conditioner
• Cooling you down (in a kitchen, home gym, or while indoor cycling)
• Mining (computer related)
• Keeping air moving in an office or dorm room
• Helping keep mosquitoes away, since they are weak fliers
• Helping dry a damp room, once the power is safe to use and the fan itself has stayed dry

What Is a Box Fan Not For?

Box fans are not for really large or really hot spaces. Box fans are not a good replacement for air conditioning.

Box fans are indoor appliances. Do not let water get into the motor, and do not leave one running unattended.

It’s always a good idea to check the specifications to make sure you’re getting the best fan for your needs.

If you want to cool a large space, you will probably need a larger floor fan, a ceiling fan or air conditioning.

Types of Box Fans

Before you choose a box fan, it’s helpful to know the different types.

Common types of box fans include:

• Personal cooling box fans
• Box fans with weather-resistant motors
• Box fans with carrying handle
• Commercial grade box fans

How Many Watts Does a Box Fan Use?

Makers list roughly 65 to 105 watts for 20-inch box fans. Lasko lists 65 to 90 watts for its Pro Power B20548, and Air King lists 65 watts on low, 87 on medium and 105 on high for its 9723.

To work out the running cost, multiply the watts by the hours of use and divide by 1,000 to get kilowatt-hours. Then multiply by the price per kilowatt-hour on your electricity bill. A 100-watt fan run for 8 hours uses 0.8 kWh. The US Department of Energy has an appliance energy calculator that does the same sum.

Using a Box Fan in a Window

The US Department of Energy says window fans work best in windows facing away from the prevailing wind, blowing hot air out of the home. Close windows near the fan and open windows in rooms far from it. In a house with more than one level, put the fan upstairs and open windows downstairs. New York State health guidance says fans in windows help when the outdoor air is cooler than the indoor air.

Check that the maker allows window use. Lasko says its classic 20-inch box fan can be used on tables, floors or in windows, and describes the motor on its Pro Power model as suitable for use in a window. These are indoor fans, so keep rain out of the motor.

Box Fan Safety

Portable fans have a fire history. A US Consumer Product Safety Commission report estimated about 4,500 fires linked to portable electric fans from 1990 through 1998, with about 270 injuries and more than 20 deaths. In 2011 Lasko recalled about 4.8 million box fans with 2002-03 and 2003-04 date stamps because a motor failure could cause a fire.

Newer fans are safer. The EPA says box fans made since 2012 have fused plugs and thermal cutoffs, and that fans built before 2012 pose known fire risks.

• Choose a fan with a UL or ETL safety mark and a fused plug.
• Do not leave a box fan running unattended. This matters most for older fans.
• Do not use an extension cord.
• Do not use a fan with a damaged cord or plug, and do not run the cord under carpet or rugs.
• Do not use a dimmer or other solid-state speed control with the fan.
• Keep water out of the motor.
• Unplug the fan before moving it or taking the grill off to clean it.
• Do not leave children unattended around a running fan.
• Keep working smoke detectors in the home.

These points come from the EPA guidance and from the owner manual for a Pelonis box fan. Follow the manual for your own fan.

Can You Make an Air Filter From a Box Fan?

Yes. The EPA describes DIY air cleaners made by attaching a furnace filter to a box fan, and recommends a MERV 13 filter for wildfire smoke. It says to use a box fan made in 2012 or later with a UL or ETL mark, and not to use an extension cord. It does not recommend building one with an older fan. If an older fan is used, it should not run unattended or while people sleep.

UL tested five box fan models with filters for the EPA and none of the test scenarios caught fire.

How Is a Box Fan Different Than Other Fans?

Here is how box fans differ from other types of fans.

Let’s go over the most important points.

Box Fan vs Pedestal Fan

This video compares a box fan and a pedestal fan:

A box fan sits on the floor (or sometimes a desk). The bottom of the box fan is flush with the floor (other than very thin stabilizing “legs”).

A pedestal fan is set atop a large, round base and has a pole that reaches up to the fan blades.

The motor and blades reside at the top of the pole. Therefore, a pedestal fan blows air at varying heights.

Pedestal fans also often include oscillation, so they swing back and forth for more airflow coverage.

A box fan is typically stationary with air flowing in a single direction.

Box Fan vs Ceiling Fan

A box fan generally sits on the floor, while a ceiling fan hangs from the ceiling.

A ceiling fan pushes air down into the room. Like any fan, it does not cool the air. The moving air makes people feel cooler.

Box fans blow air through places. If you set a box fan in a window, it can suck hot air out of spaces.

The US Department of Energy describes ceiling fans as the most effective type of circulating fan, because they move air around the whole room.

Box Fan vs Tower Fan

Box fans and tower fans both sit on the floor.

However, tower fans are usually taller and narrower, can oscillate, and offer more features (such as timers, more speed options, and air purification).

You can choose from among smart tower fans and bladeless tower fans.

Tower fans take up less floor space than box fans.

Box Fan Brands

Brands that sell box fans include:

• Lasko
• Optimus
• Comfort Zone
• Air King
• Black & Decker
• Genesis
• Impress
• Pelonis

Are All Box Fans the Same?

All box fans share a similar design and shape, but not all box fans are the same. Many have three speed settings (low, medium and high).

Certain box fans use better materials that make them more durable.

Box fans also come in different sizes and airflow ratings.

Box fans also differ in aesthetic.

What Box Fan Should I Buy?

When it comes to actually buying a box fan, take into consideration the airflow, size, durability, CFM, noise level, and price.

These are examples of box fans listed on the makers’ own sites, with the makers’ own figures. They have not been tested for this guide.

Final Thoughts

For more airflow than a box fan gives, look at a drum fan, a high-velocity floor fan or a pedestal fan.

For a desk, a small desk or tabletop fan is a better fit.

What to read next:

• What Is a Pedestal Fan
• What Is a Table Fan
• What Is a Dual Mount Ceiling Fan
• What Is a Blower Fan?

Sources

Lasko (20-inch box fan)
Air King (9723 box fan)
Comfort Zone (CZ200A box fan)
CPSC (portable electric fan fires)
CPSC (2011 Lasko box fan recall)
EPA (DIY air cleaners)
US Department of Energy (fans for cooling)
New York State Department of Health (fans in hot weather)
CDC (heat and your health)
American Mosquito Control Association

Reviewed October 2026. We corrected the size, airflow, noise and hot weather claims using maker specifications, CDC and New York State health guidance, added safety, window and running cost sections using CPSC, EPA and Department of Energy sources, and replaced untested recommendations with maker-listed examples.