A Complete Guide to Buying Air Purifiers

A Complete Guide to Buying Air Purifiers

Most people know all about air pollution and its negative impact on the outside environment, but did you know that the concentration of air pollutants can be 2-5 times higher indoors? Improving indoor air quality can reduce your risk of catching the flu, the common cold, and other airborne diseases.

One simple, effective way to improve air quality in your home is to use an air purifier.

So, what exactly is an air purifier?

An air purifier is an appliance that cleans the air around you through a special process that filters out microscopic particles that could harm your health. Air purifiers include one or more different filters that trap allergens and other particles as they pass through the air. Without an air purifier, your lungs are the only filter for airborne contaminants, meaning they must work harder to protect you from pollutants.

Pollen, dander, dust, and smoke

Just like outdoor air pollutants, there is a vast array of indoor pollutants that can impact your health. These include (but are not limited to):

  • Tobacco smoke
  • Pollen
  • Dust mites
  • Pet dander
  • Burning wood
  • Gas from stoves
  • Chemicals from cleaning products

To find out which specific types of air pollutants are present in your home, you can purchase an air monitor that will give you more information on the makeup of your home’s environment.

Fine particles 10 micrometers (microns) in diameter or smaller, including those that make up dust and smoke, are especially concerning because they can easily find their way deep into your lungs. See the chart below for examples showing just how small 10 micrometers really is.

Source: Science Notes 

Mold and mildew

While they are also both common indoor air pollutants, air purifiers do very little to address mold and mildew. To counteract this serious health hazard, invest instead in an effective dehumidifier like the Honeywell TP70WKN. These appliances can efficiently decrease the humidity level in your home, which makes it impossible for mold and mildew to thrive.


In certain situations, cleaner indoor air is especially important.

  • The more time you spend indoors, the more you’re exposed to indoor pollution, so keep that in mind if you work from a stuffy home office upwards of eight hours a day.
  • Groups like the young, the elderly, and the chronically ill are more susceptible to the effects of air pollution. This is especially true for people suffering from respiratory or cardiovascular disease.
  • People who have allergies, asthma, or chemical sensitivities, or live in a home with pets or someone who smokes.

Types of Air Purifiers

There are so many different types of air purifiers, but we’ll be focusing on some of the most common portable appliances. While whole-house units can be a great addition to your HVAC system, they’re also more expensive and require professional installation.

Mechanical filter models

  • These models use fans to push air through pleated filters that trap particles
  • HEPA filters are very popular as they can trap 99.97% of particles as small as .3 micrometers in size as well as larger pollutants like dust and pollen
  • However, these filters don’t help with gas or odors, and they can be expensive to maintain

Activated carbon filters

  • These filters use activated carbon that can trap some odor molecules as well as some gases; however, they aren’t very effective against harmful pollutants like ammonia or formaldehyde.

Ultraviolet germicidal irradiation (UVGI)

  • UVGI purifiers can kill some airborne viruses, bacteria, and fungi with ultraviolet radiation. Some bacteria are resistant to these kinds of filters
  • To be effective, these kinds of air purifiers must be particularly powerful, and the UV lights should be exposed to the air for at least several hours

Remember that even the best air purifiers aren’t good solutions for combating pollutants like mold and mildew. To fight those off, look into purchasing a portable dehumidifier for your home.


There are a few general rules that can help ensure your air purifier operates at peak proficiency:

  • Run your air purifier in a tightly sealed room. If there are any open windows or doors to the outside, the air inside can never be fully clean as it will constantly be met with an influx of pollutants from the outside. Trying to run an air purifier in this situation will only put a strain on its internal system.
  • Place your air purifier in the room where you spend the most time. For most people, this means putting it in the bedroom. However, if you work long hours, consider putting it in your office at home or at work.
  • Make sure nothing is obstructing the airflow of your air purifier. If anything is blocking airflow, it will decrease your appliance’s efficiency and could even damage it.


Keep an eye out

There are certain items you should take into consideration when shopping for your new air purifier, and these include:


  • Energy Star
    • Energy Star purifiers are 40% more energy-efficient than standard models, an important factor to consider as these appliances should be run 24 hours a day to be effective
    • Saving on energy saves you on electricity costs, so Energy Star air purifiers are your best bet if you want to keep bills low


  • Association of Home Appliance Manufacturers (AHAM)
    • AHAM has a voluntary certification program that provides clean air delivery rates (CADRs) and room size guidelines, which you can find on the AHAM Verified seal
      • CADRs describe the volume of clean air that a purifier can produce at its highest setting
      • There are different CADR ratings for different pollutants, so make sure you focus on the CADR that addresses your main air quality concern

Filter replacement cost

  • You should be replacing your filters (or cleaning those that can be vacuumed) every 6-12 months for pleated filters and every 3 months for activated carbon filters, which means you should factor filter cost into your air purifier decision
  • Large air filters have a wide range of $20-200 each, and odor-removing carbon filters usually cost around $50

Room size

  • It’s important that you’re using your air purifier in the correct size room; otherwise, you risk forcing your purifier to work extra hard to clean a space that’s too big for optimal performance
    • However, most models that are suitable for larger spaces can still be used for smaller spaces when set to low fan speeds, which has the added benefit of running with less noise output


  • Remember, your air purifier should be running all day, which means you’re going to have to live with the sound output 24/7
  • You’ll want your purifier to be as quiet as possible, but if it still produces more noise than you’d like, try running it at higher speeds when you’re out and lower speeds when you’re in the room

Features galore

There is an endless array of features offered by air purifiers on the market. Some of the most common include:

  • Pre-filters that capture big particles like hair and dirt, helping to protect and extend the lifespan of internal filters
  • Antimicrobial treatments that prevent the build-up and spread of microorganisms in internal filters
  • Air quality sensors that monitor for specific pollutants and automatically adjust the purifier so it can quickly remove the particles
  • Filter replacement indicators that tell you when your filter needs to be cleaned or replaced
  • Adjustable fan speeds that let you control the strength and noise level of your purifier
  • Wi-Fi capability and apps that allow you to control your purifier from almost anywhere

Breathe a sigh of relief

Now that you know all about air purifiers, you’re well equipped to buy the right one for you and your family.


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