Air Purifier Buying Guide

Air purifiers have spiked in popularity since the pandemic and the fact that more of us are working from home than ever before. An air purifier will essentially filter any airborne pollutants from your air, such as smoke, pollen and dust, and some have also been advertised as capable of capturing particles carrying the COVID-19 coronavirus.

air purifier buying guide

The first step to filtering out air purifiers (no pun intended) is figuring out how much space you want your device to clean. Small desktop devices aren't effective in large living spaces, while larger, heavy-duty air purifiers may be overkill in your kid's bedroom.

One way to find the best fit is to look at "air changes per hour." This metric may be included in your air purifier's specs. It can help you understand how filtration works in practice, as a smaller air purifier could turn over the air in a 350-square-foot room eight times in an hour but manage just four air changes per hour in a 700-square-foot room.

Some air purifiers are better at filtering out certain types of pollutants than others. If your main concern is cigarette smoke, for example, you may need a different device than someone who lives with a lot of pets.

Air purifiers are rated based on how well they filter different pollutant sizes. While most air purifiers are similar across the board, some are slightly more effective at catching dust and dander than smoke (or vice versa).

Most air purifiers are labeled with a clean air delivery rate (CADR) number, a metric developed by the Association of Home Appliance Manufacturers (opens in new tab) (AHAM) that helps consumers understand how effective a device is at filtering various particles in a specific room size.

Also, keep in mind that an air purifier's CADR rating reflects the best-case scenario. These numbers are determined in controlled testing environments. Variables in your home, such as drafts or dampness, may prevent your air purifier from hitting its optimal rating.

Finally, not every air purifier is tested using the CADR system. The manufacturer of the IQAir HealthPro Plus (opens in new tab), one of our recommended models, has not submitted the device for AHAM testing. Read independent reviews to get an idea of how well an air purifier works in these instances.

The air purifiers we recommend use mechanical filtration, meaning that their filters physically trap the pollutants that pass through them. Your air purifier likely has at least two such filters: a prefilter, which catches large particles like pet hair, and the main filter, which nabs smaller pollutants.

What really matters is your air purifier's main filter. In general, you'll want to look for an air purifier that uses a high-efficiency particulate air (HEPA) filter, the standard recommended by the EPA and the American Lung Association.

Some air purifiers advertise filtration processes that rely on ionizers or ultraviolet (UV) light. The effectiveness of these devices isn't well demonstrated. They may also produce ozone, which is a lung irritant that could make any breathing-related problems worse rather than better.

Most air purifiers have internal fans that pull air through a series of filters. Some of these fans are practically silent, especially on low settings. Others make a humming sound as you turn them up.

You'll find noise-level ranges measured in decibels in your device's specs. We've seen air purifiers, such as the Blueair Blue Pure 411, rated as low as 17 dB (similar to rustling leaves). Others, such as the Austin Air HealthMate HM400 (opens in new tab), can reach noise levels of more than 60 dB (akin to an AC unit 100 feet away).

The larger and heavier air purifiers are best kept stationary, though some come with casters for portability. If you want to use your air purifier in your home office during the day, your living room in the evening and your bedroom overnight, look for a smaller device or one that rolls.

As we've mentioned, the size of an air purifier is loosely correlated to the size of the room it can effectively clean, so the best option for your nursery probably won't be the right choice for a family room that's three or four times larger.

The up-front cost of your air purifier matters if you're on a budget, but don't assume you'll be done paying for the device once you have set it up in your home. You'll have to periodically replace the filters on an ongoing basis.

Air purifiers are most effective when they're running almost constantly, so you'll also want to factor in electricity costs. Some of the air purifiers we recommend are Energy Star-certified, but each one pulls varying amounts of power depending on the fan speed you're using.

You can usually find your air purifier's estimated energy usage in the product specs. We've seen devices that supposedly draw as little as 1.5 watts on low, as well as power-hungry ones that draw more than 200 watts on high. You may not even notice the impact of the former on your electricity bill, but the latter could add up.

These extras can add convenience to an air purifier, but they're not necessarily worth the added expense. For instance, you could set a calendar reminder to change your filter based on your air purifier's maintenance schedule, so you don't need the filter replacement light.

However, the smart connectivity can be useful if it displays the difference the air purifier is having on the environment. Dyson's models are known for doing this. That way you can see the current quality of the air to much greater detail.

Our top air purifier pick, the Coway AP-1512HH Mighty (opens in new tab), includes several of these nice-to-have features and is reasonably priced. But in general, we'd recommend prioritizing other factors if your budget is a concern.

There is no single air purifier that's right for everyone. When you're shopping for an air purifier, always look first at the CADR ratings and filter types to get an idea of how effective the air purifier will be for your specific needs.

Once you've identified an air purifier that offers the best filtration for common pollutants in your home and that is the right size for your space, evaluate secondary features like noise levels and portability. Also make sure that the air purifier's energy costs and ongoing maintenance costs are within your budget.

For a fraction of the cost, Smart Air provides empirically backed, no-nonsense purifiers and masks, that remove the same particles as the big companies. Only corporations benefit when clean air is a luxury.

Smart Air is a social enterprise and certified B-Corp that offers simple, no-nonsense air purifiers and provides free education to protect people from the harms of air pollution. We are proud to be the only certified B-Corp dedicated to fighting air pollution.

Air purifiers typically have three layers of filtration media: a pre-filter for large debris such as dust and hair, an activated carbon filter for odors and VOCs, and a particle filter (usually HEPA) for very small particles. They're meant to be run 24/7, usually with one unit covering a single room.

Some companies use UV lights to kill bacteria and viruses that enter into the air purifier's filter. You can read about UV light's effectiveness, or lack thereof, here and here. In short, the amount of time needed to kill those viruses and bacteria is longer than the time they're typically exposed to it in these air purifiers. Killing them is also not actually required -- trapping them inside the particle filter essentially gives the same end result.

Each unit has different cleaning and filter replacement schedules. Some have filters that last several years, while others require manual cleaning and buying of replacements every few months. While one unit may appear substantially more expensive than another, the cost of replacement filters and the time needed to clean them should be taken into consideration too. The higher initial cost sometimes makes up for the long-term cost.

The amount of activated carbon determines whether any given air purifier can practically filter out smells, smoke, and VOCs. Most low-end units include a very small amount that won't actually make a difference. Carbon typically saturates faster than HEPA filters, so the ones with a small amount of it become entirely useless for gas filtration within a short period of time.

With so many different air cleaners on the market today, trying to figure out what makes a good air purifier and selecting the right air purifier for your home can be a frustrating task. To a lot of people, these machines seem complicated to understand, and for good reasons too.

Because a high quality air purifier can trap 99% of all air pollutants that would otherwise enter into your nasal passage and lungs. Pre-filtering the air in this way takes a lot of stress off of your lungs and ensures that you only breathe in clean, fresh air while indoors.

Keep in mind that air purifiers are different than air quality monitors. An air purifier will actually remove the pollutants from the air while even the best indoor air quality monitors cannot. An air quality monitor simply detects the types of contaminants in the air and reports the level of various substances. These units are good for people who want to know exactly what types of pollutants are in the air so they can find the root source to eliminate them.

Air purifiers are an excellent way to cut down on dust and dust mites by sucking in and trapping these things before they ever have a chance to collect around your home. People who want to clean less often find air purifiers to be a great investment.

As explained in our article on how do ionic air purifiers work, some of these devices also include an electrostatic collection plate that attracts the fallen particles and removes them from the room. This process eliminates ultra-fine particles down to 0.01 microns in size.

Many people confuse HEPA air purifiers with ionic air purifiers and air ionizers. While they all can remove particles from the air, each unit works in a different manner to do so. Check out our guide on ionic air purifier vs HEPA filter to get more details. 041b061a72