How to Buy an Air Purifier

We created this air purifier buying guide to help you understand what matters, the questions to ask, and the key differences HEPA-style and Brio air purifiers.

Why is indoor particle pollution so important? >

We've known for many years, from scientific research, that inhalable particle pollution inside homes can create damaging short and long-term health consequences, including respiratory ailments and diseases such as asthma and chronic obstructive pulmonary disease (COPD), as well as heart disease, cancer, and even dementia.

According to the EPA, indoor air pollution is one of the top five environmental risks to public health. And the World Health Organization considers PM2.5 the world’s single biggest environmental health risk.

PM2.5 (Particulate Matter that is smaller than 2.5 microns) is way too small to see, dangerous, and is also the most commonly found indoor air pollutant.

Takeaway: Select an air purifier that is really good at removing fine and ultrafine particles smaller than 2.5 microns.

What are the top three things to consider? >

1. Be sure it is tackling the job at hand. For most people that means focusing on removing fine and ultrafine particles from germs, viruses, smoke, dust, and more. Invisible particles are the most common indoor air pollutant.

2. Make sure the air purifier is sized properly to clean the air. To determine this you, need to consider three things: room size, desired air changes per hour (ACH), and the clean air delivery rate (CADR). More on those below.

3. Look at effectiveness not just efficiency. Many HEPA-style air purifiers are efficient in blocking particles. But blocking and trapping only goes so far. That same efficiency causes filter clogging so less air gets through the filter, and less air get purified. Filter clogging reduces effectiveness. Often quickly.

Brio uses APART technology, not HEPA filtration, to do the job with no clogging. So airflow stays high and more clean air circulates into the room.

Anything else to keep in mind? >

Pay attention to annual costs. How many filter changes will you need to maintain peak effectiveness? It may be more than the manufacturer suggests. Sometimes much more. Do the math and you'll see that over several years, frequent filter changes can really add up, especially if you have more than one air purifier in your home or office.

In dust-loading tests, Brio stayed at peak effectiveness 5-10x longer than tested HEPA-style air purifiers. That's a lot fewer filters to buy, to change, and to discard.

Consider convenience. Is maintenance minimal? The air purifier you select should be easy to operate and maintain, with simple (no tools needed), infrequent filter replacement.

While conditions and use may vary, in a typical US environment, Brio's APART Collection Cartridge stays at peak performance for one year or more.

In addition to particles, find out what else the air purifier removes. Does it remove formaldehyde? Odors? To do so requires special technology or a very, very large and very frequently replaced carbon filter. Carbon gets used up in the removal process, so even several pounds of carbon or activated charcoal will only last a short amount of time. So be skeptical of claims made about odor and formaldehyde reduction. Look at a product's reports and testing instead of general promises.

Does it fit into your lifestyle and home? Is it nice to look at, with a small footprint and an appearance that does not cramp your style? Remember to check the dimensions before you buy.

What about ozone? >

The last thing you need is an air purifier that makes your air quality worse. 

To ensure ozone safety, select an air purifier that is certified by the California Air Resources Board (CARB), which has the most stringent ozone standards in the country. If an air purifier isn't CARB certified, don't buy it.  Brio is CARB certified. Most HEPA air purifiers are certified as well.

You should avoid using ozone generators as these are recognized as unsafe.

Ambient ozone is another concern to consider. Stratospheric ozone is good, protecting us from the sun’s ultraviolet rays. Ground-level or ambient ozone, on the other hand, is a health hazard. The product of a chemical reaction between sunshine and pollution from cars, power plants, refineries, and other sources, ozone is a major element in smog.

So, if you live in an area where there are smog and ozone alerts, it is likely that ground-level ozone is getting inside your home as well. 

Ambient ozone indoors can equal 10-20% of the outdoor ozone, so it's a real concern in many urban areas.

Most HEPA air purifiers don't have dedicated technology to remove ambient ozone.

Brio includes a filter designed specifically to remove ambient ozone as air flows through the filter.

What type of air purifier should I choose? >

Two distinct types of air purifier technologies–HEPA and APART™–are best suited to removing fine and ultrafine particles, including dust, pollen, pet dander, wildfire smoke, mold, and viruses.

HEPA filters have been around since the 1940's and the basic technology hasn't changed much. HEPA filters can be very efficient – meaning they trap a lot of particles – but they also have a design limitation. As they trap particles, the filter clogs and rapidly loses effectiveness. Air cannot flow easily through a clogged filter, so performance goes down, often long before a planned filter change.

Patented APART (Advanced Particle Removal Technology), introduced with Brio portable air purifiers, overcomes many HEPA air purifier issues, by drawing particles out of the airflow, and into a collection cartridge instead of blocking airflow and clogging a filter.

Other types of air purification technology – including ionization, photocatalytic oxidation (PCO), and UV light – are not designed to remove particles, so they aren’t considered here.

How do I find the right air purifier for my room and my concerns? >

CADR? CFM? ACH? The alphabet soup of terms doesn’t make it easy to make a decision.

To simplify things, start by determining your room size in square feet.

 Next think about your air quality issues. Are you concerned with general wellness or ongoing health issues such as allergies and asthma? Worried about environmental pollution infiltrating your home? Or more acute concerns like wildfires or viruses? The more significant the concern (and this can vary from day to day) the more quickly you will want the air to circulate through the air purifier. For general wellness, every 30 minutes might be fine. For allergies and asthma or other acute issues you may want to circulate the air three, four or five times an hour. The number of times the air circulates through the air purifier in an hour is known as the ACH (for air changes per hour)

Air quality experts recommend a minimum of 3 air changes per hour – or a full air recirculation at least every 20 minutes for typical homes. The higher the ACH, the faster an air purifier can clean the room and the more effective it will be in keeping the room clean.

It’s important to understand, however, that if you want a higher number of air circulations per hour, this will reduce the size of the room that can be cleaned for any air purifier.

Along with room size and desired air changes per hour the third thing to consider is CADR, which stands for clean air delivery rate. CADR measures the initial effectiveness of a new air purifier in reducing particle concentration in a room. CADR gives you a way to compare new air purifiers (with new filters) and is used to determine the maximum size room any tested air purifier will clean. CADR can be thought of as the initial cleaning power of an air purifier.

There's more to selecting an air purifier than just CADR (specifically effectiveness over time), but it is a good starting point.

Once you have determined the room dimensions, and that you want to keep the air changes per hour (ACH) at 3 (every 20 minutes) for example, you can use a simple rule of thumb to determine the clean air delivery rate (CADR) needed to get the job done well.

You can multiply the room size by 0.4 to get to the minimum CADR needed for your space.  Looking at it the other way around, you can multiply the published CADR for any air purifier by 2.5 to determine the maximum room size that can be effectively cleaned every 20 minutes.

So, for example. If you have a room that is 325 square feet, you will need an air purifier with a CADR of 130 or higher. Or if you were evaluating a specific air purifier you could multiply the published CADR by 2.5 to determine what size room it cleans every 20 minutes.

Another example: If the CADR is 200, multiply this by 2.5 to get 500 square feet, the maximum room size that can be cleaned effectively.

Which matters more: effectiveness or efficiency? >

For your health, effectiveness is what matters. So, effectiveness is the key to selecting the right air purifier. 

Many HEPA air purifier manufacturers like to talk, instead, about efficiency.

Efficiency focuses on how well an air purifier blocks and filters particles. Which sounds good, until you realize that HEPA efficiency causes the airflow to drop. And no airflow means no air cleaning.

Long before the recommended filter change, many HEPA filters—especially the more efficient ones—can drop off in effectiveness to below half their initial cleaning power. Blocking and trapping particles also blocks airflow.

Because it uses non-clogging APART technology, Brio's airflow stays high as it captures particles, for consistent effectiveness.

What do I need to know about filter cost? >

Over several years of ownership, the true cost to own can vary widely between air purifiers. That difference can add up when you have just one air purifier, and can become a major expense with several air purifiers in your home or office.

Purchase price matters, energy costs matter, but year after year, the biggest expense you are likely to have is replacement filter cost. It can easily add up to more than the initial purchase price for your air purifier.

Here's why: For HEPA-style air purifiers, the typical filter replacement recommendation is at six months. But that doesn't take into account filter clogging and the declining clean air delivery rate that goes with HEPA technology. As the HEPA filter performance drops off, you will need to increase the the number of filter changes per year for your air purifier to work effectively.

Brio works differently and avoids this declining performance issue altogether.  Because particles are drawn away from the airflow, there’s no clogging. Our testing has shown that Brio’s APART Collection Cartridge can last five to ten times times longer than a HEPA filter in the same environment. 

Takeaway: Do the math. You might be surprised at how filter costs factor into the cost to own over time.

Do I need a particle sensor? >

Particle sensors and air quality monitors that are included on an air purifier have a few issues. The air quality is relatively cleaner immediately surrounding the air purifier so the reading from the monitor or sensor will not accurately represent the air quality in the rest of the room. And on-board monitors often have difficulty staying in calibration, which can lead to inaccurate readings.

You would not know this without an independent monitor providing another reading. For this same reason, you may want to avoid using the auto mode on your air purifier. Auto modes can be inaccurate, often underreacting as they rely on a particle sensor that is only measuring particles near the unit.  Or that is not well calibrated.

The best type of particle sensor is one that is placed at a distance from the air purifier and provides an independent reading—either as a check on your on-board air particle sensor or as an independent measurement.

Takeaway:  Skip the auto mode. Instead, leave the air purifier on all day, all night, and all year. And if you are concerned about measurement of your IAQ, add a separate, high-quality IAQ monitor elsewhere in the room.           

Do air purifiers need a lot of maintenance? >

It depends. Some require frequent filter changes to stay at peak performance. And require that you use tools to replace the filter. Filter changes should be simple and easy—no tools or instructional videos needed, period.  Look for a disposable, long-life cartridge or filter that’s easy to change.

Brio's long-life, disposable cartridges are fast and easy to change, because you have better things to do with your time.

Brio room air purifier - rear panel door

Add Brio to your home or office for peace of mind and better indoor air.