Buying guide for Best air purifiers under $100

If you or someone in your home suffers from a chronic sore throat, cough, headaches, or trouble breathing, it might not be a cold or the flu. It could be indoor air pollution. If that is the case, purchasing an air purifier is an excellent first step toward regaining your health.

You may have heard that air purifiers cost a lot of money. If you are on a tight budget, you may worry that you won’t be able to afford the cure for what ails you. However, if you are willing to work within certain parameters, it is possible to find a quality air purifier that is effective and costs less than $100.

To learn what factors and features are most important in an air purifier so you can get the best bang for your buck, keep reading. If you're ready to purchase an air purifier that costs less than $100 and just want a few recommendations, consider the models we share on this page.

The Environmental Protection Agency warns that pollutants may occur in concentrations two to five times greater indoors than outdoors. Since Americans spend up to 90% of their time indoors, it is important to have some kind of air filtering system in the home.

Key considerations

What an air purifier removes from the air

Before purchasing an air purifier, check to see what it can remove from the air. The possibilities include dust, pollen, pet dander, ash, smoke, odors, mold, bacteria, and other microorganisms.

How large of a room an air purifier can clean

The job of an air purifier is to clean the air in a particular space. At the highest end of the price spectrum, an air purifier can work on an entire house. For models under $100, however, you have to be careful, as they may only be powerful enough to clean a small bedroom.

Determine the square footage of the space you want to treat (the length of the room times the width), and match that to your desired air purifier. If your room is 200 square feet and the air purifier you are considering only works on 50 square feet, it won’t be truly effective.

Air purifier types

There are three main types of air purifiers that we'll discuss in this guide: ozone generators, ionizers, and mechanical filtration units.

Ozone generators: Ozone destroys living things. It is an effective air purifier because it can kill bacteria. The bad news is that ozone does not discriminate: it treats lung tissue the same as it does mold. If you choose an ozone generator, you should first learn the ins and outs of how to use one safely.

Ionizers: Think about static electricity and how it can make clothes cling to each other when they are removed from the dryer. In essence, this is how an ionizer purifies the air: it charges particles so they cling to curtains, walls, and furniture. While this sounds like a great way to get allergens out of the air, the downside is that the ionization process creates ozone as a byproduct, albeit in much lower concentrations than an ozone generator.

Mechanical filtration units: Different types of filters remove different elements from the air. For this reason, it is best to have an air purifier with a multi-stage filtration system. A pre-filter removes the largest particles; an activated carbon filter removes odors, pollutants, volatile organic compounds, and radon; and a high-efficiency particulate air (HEPA) filter removes at least 99.97% of particles down to a size of 0.3 microns (human hair is roughly 70 microns). A multi-stage filtration system is by far the safest way to purify the air in your home.

Features

Fan speed

A quality air purifier will offer at least three fan speeds (low, medium, and high) so you can move the air at different rates. You may need to place the unit on high in adverse conditions. Medium or low might be fine for maintenance.

Timer

A timer isn't smart technology, but it gives you some control over the air purifier by automatically turning it off after a designated amount of time.

Sleep mode

Some air purifiers feature a quiet mode so the unit will operate in near silence while people sleep.

Night light

Also, for nighttime use, some models have a night light that can be left on or shut off while you sleep.

Once particles are no longer suspended in the air, an air purifier cannot eliminate them. At that point, you will need a vacuum with a HEPA filter that traps the particulates.

What you can get for under $100

A shrewd shopper can get an air purifier with a multi-stage filtration system that eliminates mold, bacteria, odors, smoke, pollen, pet dander, and more for under $100. In fact, the right low-price air purifier has almost the same purification capabilities as a pricier model. The best choices feature a pre-filter, an activated carbon filter, and a HEPA filter.

You can find small ionizers and ozone generators in this price range as well. The areas where you will need to compromise are room size and bells and whistles. An air purifier for under $100 is usually only effective in a smaller room, and it won't offer any of the advanced features of pricier air purifiers.

If you'd like to spend a little extra, you could gain some extra features. For example, for over $100 (and we mean starting close to $300), you can get an air purifier that works in a larger room, cycles through the air up to five times an hour, and may even be compatible with smart devices. One of the most useful features you can find on high-end models is a sensor that tests the air quality in your home to let you know precisely how good it is.

How to figure out the cost of running an air purifier

• Locate the silver sticker on your air purifier. It will most likely be on the bottom of the unit. On this sticker, you can view the wattage of your air purifier. (If the wattage isn't listed, simply multiply the volts by the amps to get wattage.) For example, let’s say you have an air purifier that consumes 55 watts of power (per hour).
• Multiply the wattage by the average number of hours that you run the air purifier each day. If you were to run it 12 hours a day, you would multiply 55 x 12 to get 660. Since there are an average of 30 days in a month, multiply that number by 30: 660 x 30 = 19,800.
• Divide your answer by 1,000 to get the total billable wattage each month. Because electricity is billed in kilowatt-hours (a kilowatt is 1,000 watts), you would use this formula in this scenario: 19,800 ÷ 1,000 = 19.8 (kilowatts).
• Look at your electric bill or contact your electric company to find out your rate. Each electric company charges its own rate. To give you a ballpark figure, the average cost of electricity in the U.S. at the moment of this writing was $0.13 per kilowatt-hour. The final step is to multiply: 19.8 x $0.13 = $2.57. Therefore, to run a 55-watt air purifier for 12 hours every single day of the month would cost a total of $2.57 per month. Not bad.

High humidity can diminish the expected lifespan of an air purifier. It is best to keep the machine away from rooms with high moisture content, such as the bathroom.

FAQ

Q. What are the benefits of using an air purifier?

A. First and foremost, an air purifier can reduce indoor air pollution, making the air healthier to breathe. If you suffer from allergy symptoms, the right air purifier can reduce those symptoms by removing allergens from the air. Certain air purifiers can even remove odors and harmful volatile organic compounds from the air.

College students can improve the often stale air quality of dorm rooms by adding an air purifier.

Q. Where is the best place to put an air purifier?

A. Place your air purifier as close to the source of indoor air pollution as possible. It functions best in a room with closed windows and doors so it can efficiently process all of the air inside the room. If the air purifier is not specifically designed to be a floor model, it should be placed on a desk or table several feet above the floor.

Q. How long should I leave my air purifier running?

A. Imagine if the water coming into your home was only purified for a few hours each day. You probably wouldn't be very happy. Now, think about the air you breathe only being purified occasionally. That doesn't sound like the healthiest option. For this reason, most air purifiers are designed to run 24/7.

However, it is wasteful to leave something running when it is not needed. For this reason, some air purifiers (generally those for which you would need to spend more than $100) have a built-in sensor that measures the air quality. If the air in the room is clean, the unit will shut off so it doesn’t run needlessly.