Product Reviews ➜ Air ➜ Purifiers
Best Air Purifiers
Dr. Meg Christensen is the physician founder of Interior Medicine, a non-toxic home resource built on her background in medicine, biochemistry, epidemiology, and clinical research.
➜ VOCs are what make your indoor air 2-5x more polluted than outdoor air. I evaluate air purifiers on what actually matters: substantial activated carbon for VOCs, true HEPA for capturing allergens and inevitable PM2.5 spikes, low noise levels, and no gimmicky ionizers, bright blue lights, or harmful ozone.
Updated July 15, 2026
Winix 5510: Best Air Purifier Overall
Winix is the best air purifier overall because it does all three important jobs an air purifier should do and it’s very affordable: First, it has a large washable pre-filter to capture pet hair and dust. Second, it has a true HEPA filter that removes smoke, mold, pollen, and bacteria. And third, it has 0.5 lbs activated carbon adsorbs odors and VOCs—pet smells, wildfire smoke, and cooking fumes. It's very quiet, even on higher speeds. It does have “PlasmaWave” ionization (generates <0.01ppm ozone—technically safe but unnecessary). I recommend just keeping it off.
AirDoctor 3500: Best Upgrade Air Purifier
Only listed in second place because it’s more pricey and I want air purifiers accessible for all, the Air Doctor 3500 has 1.5 lbs of activated carbon—triple the Winix and much better than the thin carbon cloth in most air purifiers. Important for removing toxic VOCs from wildfire smoke, new construction off-gassing, and odors. It does very well in third-party testing for PM 2.5 removal, and looks more polished than the Winix. Great for dealing with smoke, odors, and moderate VOC concerns. Check the price and for discounts on the Air Doctor website directly (requires some scrolling) or on Amazon.
Medify: Best for Small Rooms and Medical Grade Air Purifier Needs
Medify has expanded their small room air purifier options, and they’re special because they each contain a substantial amount of carbon. Many are under $100, making them ideal for nurseries and small rooms. Their MA-112 option, pictured above, is unique for its H14 medical-grade HEPA filter—a higher standard than typical H13 filters, and has excellent air flow. It also has 2 lbs of activated carbon for VOC removal: it helps with mold mustiness, wildfire smoke, cooking odors, and off-gassing. (FYI, Medify is humble in its description — it can remove particles 10-100x than 0.3 microns; read my guide below about why.) Medify accepts HSA/FSA. Get $15 off with code INTMED15.
Austin Air HealthMate Plus: Best for VOC Removal
These air purifiers have clinical research by Johns Hopkins showing they can remove gasses, including nitrogen dioxide (NO2) which is produced by gas stoves and heater. It’s what I use in my house for this reason. VOCs remain elevated daily and year round, while PM 2.5 spikes during cooking and wildfires, so I focus on VOC removal. This is hands down the best air purifier for VOC removal because it has 15 lbs (!) of activated carbon-zeolite. Zeolite specifically targets formaldehyde, which even carbon can't remove. I also appreciate that it’s made of steel, making it the closest to a plastic-free air purifier available. It has a true HEPA filter, removes 90% of PM 2.5 within one hour and runs very quietly at 42dB. The filter lasts 5 years, which is also nice for low maintenance.
BlueAir 211i Max: Best for Aesthetics and Large Rooms
This Blueair model now has a new high-carbon filter —not as intense as the first four air purifiers listed above, but better than the standard filter, for tackling toxic VOCs from wildfire smoke and odors. I was initially skeptical of their "HEPASilent" technology but unlike the vast majority of gimmicky “HEPA alternatives,” Blueair proved theirs worked with testing and is AHAM certified for PM 2.5 removal. So, it performs equivalently to true HEPA for mold, dust mites, smoke, and fine particles. Very quiet and designed for large spaces (up to 600+ sq ft at 5 air changes per hour). You can get it through BlueAir’s website or Amazon.
BlueAir Dust Magnet: Best Air Purifier for Dust and Allergies
Another BlueAir model! The DustMagnet, as its name implies, has two large-surface filters and high airflow optimized for capturing dust, pet hair, and pollen. It is less efficient at smoke and VOC removal compared to Blueair's other models or the models above. The carbon-coated filter provides minimal VOC removal—but is totally fine for everyday odors, just inadequate for wildfire smoke or new building off-gassing. Very quiet, bedroom-friendly with coverable indicator light, works as a little table, and is cute. You can get it on Blueair’s website or Amazon.
Looking for something specific? If you don't see the product or brand you're curious about, you can request a review here, or run it through the Second Opinion Product Checker to evaluate it yourself. Want to go deeper? My free course covers how to evaluate any product's materials yourself.
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Air Purifiers Explained: Your Complete Guide to HEPA, VOCs, Certifications & What Actually Works
Table of Contents
How do air purifiers work? A visual explanation of the three filter types and air flow through them
What good air purifiers can actually remove: a chart of particles and gases
Air purifier logistics: how many to get and where to place them
The Best Air Purifier Review Website
How Interior Medicine Rates Air Purifiers
This is the scale I use, consistent across all product categories. It runs from lowest to highest. For air purifiers, each tier reflects three things: verified (not just claimed) particle removal efficiency, how much gas adsorbent capacity the machine has, and whether or not it adds anything harmful, like ozone, blue light, or excessive noise.
PM 2.5 Removal: AHAM Verifide smoke CADR of 250 or above (or 95%+ PM2.5 reduction in 60 minutes in a 150+ sq ft room, converging across two or more independent outlets)
VOC Removal: 5 or more pounds of carbon and/or formaldehyde-capable media (potassium permanganate, amine-treated carbon, or a mineral blend)
No Harm:No ozone, ionizer, or blue light, or all of them optional, and running under 45 dB (noise level) at the speed you'd actually use daily.
High
PM 2.5 Removal: Same as highest. AHAM Verifide smoke CADR of 250 or above (or 95%+ PM2.5 reduction in 60 minutes in a 150+ sq ft room, converging across two or more independent outlets)
VOC Removal: 1.5 or more pounds of carbon but no formaldehyde-specific media
No Harm: No ozone, ionizer, or blue light, or all of them optional, and running under 50 dB (noise level) at the speed you'd actually use daily.
PM 2.5 Removal: AHAM Verifide smoke CADR of 150 or above (or 90%+ PM2.5 reduction under the same conditions)
VOC Removal: 0.5 pounds or more of carbon
No Harm: No ozone, ionizer, or blue light, or all of them optional, and running under 50 dB (noise level) at the speed you'd actually use daily.
Low
No PM 2.5 Removal: Unverified particle performance, or verified performance below the Moderate bar
No VOC Removal: Less than 0.5 pounds of carbon (including carbon-coated fabric)
Harm: Excessive noise or blue light function can’t be turned off
Lowest
No PM 2.5 Removal: Unverified particle performance, or fake performance claims (water, moss, PECO, probiotic, etc)
No VOC Removal: No carbon
Harm: Ozone generator can’t be turned off, or excessive noise or blue light function can’t be turned off
Air purifier performance is easy for brands to claim and hard for people to check, because air and its contaminants are invisible and can be complicated and expensive to measure. The stats and specs are hard for most people to interpret too. For example, CFM is not a useful performance figure: it tells you how much air moves through the machine, not how much of it comes out clean. AHAM Verifide is the only third-party standard in the US, and it's voluntary, so a number of even well-regarded brands skip it. Where a brand hasn't certified, I use independent outlet testing, but only when the outlet publishes its method and raw data and only when two or more of them converge.
Keep reading for more details.
What are the best air purifier reviews?
Interior Medicine has the best air purifier reviews, and my recommendations are above.
What Interior Medicine doesn’t do: vibe-based reviews. The majority of air purifier reviews and round-ups are based on anecdotes, star-ratings, ease-of-use, budget, aesthetics, and sometimes even potential for affiliate commission, if they’re part of a blog round-up. This can lead to air purifier recommendations for machines that don’t actually work, or even have harmful technologies (ozone generation, for example). While of course some of these things (like budget and ease of use) are absolutely practical, this type of review is where the placebo effect comes in to play: when someone buys an air purifier they think will work, it can make them feel like their air is cleaner even when it isn’t. This has happened in real life: the $800+ Molekule had great reviews before it was discovered, through testing, to be one of the least effective air purifiers on the market. It was expensive, aesthetically pleasing, and had great marketing that sounded better than HEPA…but it didn’t work at all. (They retracted their claims and added a regular HEPA filter to their machines.) Human experience just isn’t super reliable in this area, and in my opinion, fashion blogs shouldn’t be considered a reliable source. Air purifiers ultimately are a health tool, and the standard for ratings should be higher.
Are there any 3rd party certifications for air purifiers?
Very few. And, the ones that exist are voluntary. Air purifiers are a very inconsistent and unregulated industry, especially for portable in-home air purifiers that the majority of people need.
CARB (the California Air Resources Board) and UL (Underwriters Laboratories) are third parties that verify that air purifiers don’t generate ozone.
AHAM (Association of Home Appliance Manufacturers) has standardized the clean air delivery rate (CADR) but it only applies to how well a purifier can clean air with dust, pollen or tobacco smoke (not VOCs, viruses, or other contaminants).
HEPA is not a 3rd party certification, but legally, a company can only say their filter is a HEPA filter if that is indeed true.
Do air purifiers actually work?
Do air purifiers work?
Yes. Air purifiers with true HEPA filters, good air flow stats, and third party testing work. They can both improve your health and the health of your home.
Indoor air is 2-5 times more polluted than outdoor air, even if you can’t smell or see how bad it is. Air purifiers reduce your indoor air pollution by removing Particulate Matter (like wildfire smoke, mold spores, and pollen.) Air purifiers with adsorbents can also remove VOCs (like formaldehyde). Lowering your daily exposure to particulate matter and harmful VOCs can help reduce your risk of long-term health problems.
Are air purifiers worth it?
Yes, absolutely. If you’re like most people, you spend around 90% of your time indoors, and a lot of that at home. While you can’t control the outdoor air quality, you can control your indoor air quality. As long as you choose one that actually works, an air purifier is one of the best investments for your overall health.
As wildfire smoke and poor outdoor air quality become more common, an air purifier that removes dangerous PM 2.5 and VOCs from smoke can protect not only your lungs but your whole body. Ultra-fine particles are able to cross through the surface of the lungs and into your bloodstream, which is one of the reasons why PM 2.5 exposure is related to inflammatory, chronic conditions.
Why is it hard to find a good air purifier?
Air Purifiers are high tech, expensive, increasingly important for people to have, and work on an invisible level. Unfortunately, this creates a perfect storm for healthwashing, and the number of air purifier companies making false claims to trick customers into thinking they’re buying a superior product has been well-documented as a problem.
How Do Air Purifiers Work?
Air purifiers work using a combination of filters and generating good air flow intake that forces dirty air through those filters:
First, the filters. Air purifiers generally use a three-stage filtration system to remove three different types of pollutants from indoor air.
Stage 1: Pre-Filter (Captures Large Particles)
The pre-filter is the first line of defense, capturing large airborne particles including:
Pollen and allergens
Pet hair and pet dander
Dust (including larger dust mite particles)
What to look for: If you need an air purifier for allergies, pets, or dust removal, prioritize an air purifier with a large washable, reusable pre-filter to reduce long-term maintenance costs. Regular cleaning (every 2 weeks) keeps your air purifier running efficiently.
Stage 2: True HEPA Filter (Removes 99.97% of Microscopic Particles)
A true HEPA filter (High-Efficiency Particulate Air filter) captures small particles, including:
Wildfire smoke particles
Mold spores and mycotoxins
Dust mite allergens and feces
Bacteria and some viruses
Other fine particulate matter (PM 2.5)
Important fact: to be called a true HEPA filter, it must meet strict standards, and be able to remove 99.97% of particles 0.3 microns in size, as well as particles much larger and smaller. This is the gold standard for air purification and this is the most important part of an air purifier, because we have so much research showing how PM 2.5 exposure is harmful to the body. Read more below for more details on how HEPA filters work and for a visual diagram.
Stage 3: VOC Filter (Adsorbs Odors, VOCs & Gases)
The VOC filter or gas adsorbent (often an activated carbon or sometimes a mineral blend) removes gaseous pollutants too small for HEPA filters to catch, including:
Volatile organic compounds (VOCs)
Cooking odors and kitchen smells
Smoke odors from cigarettes or wildfires
Formaldehyde from new furniture, carpets, and building materials
Chemical fumes and off-gassing from paint or cleaning products
Not every air purifier has this layer. These are less common than HEPA filters, and often are minimal, just a carbon cloth. Substantial adsorbent filters can contain up to 15 pounds of carbon, zeolite, or other mineral blends that are capable of sequestering formaldehyde and other gases. Read more below to see how adsorbent works and for a visual diagram.
Pre-Filters in Air Purifiers
A pre-filter is the first stage of filtration. It’s usually a coarse mesh or fabric screen sitting in front of both the HEPA and VOC filters. It catches the big, visible stuff before it reaches them, like pet hair, lint, dust bunnies, dander clumps, and larger pollen. It works by simple sieving, similar to the way a screen door works. The particles are just too big to fit through.
The pre-filter's real job isn't cleaning your air, but protecting the expensive filters behind it. A HEPA filter would capture pet hair perfectly well, but it would clog fast doing it, and HEPA filters are relatively expensive and something you have to replace. A pre-filter is cheap, and most are washable or vacuumable. That means a pre-filter mostly affects filter life and running cost, not what comes out of the machine. Vacuum it monthly, and if you rinse it, let it dry completely before it goes back in!
One thing to watch: "carbon pre-filter" is commonly marketed, and it can mean a thin carbon coating on the mesh, or a relatively thin carbon pad. These won’t do any substantial VOC removal: you need pellets on the order of pounds to do that.
What HEPA Filters Remove
The graph below shows how good HEPA filters are at capturing particles that are 0.3 microns in size, the hardest size of particle for any air filter to capture:
Bigger particles get caught by impaction and interception. Smaller ones drift into fibers by diffusion. Around 0.3 microns neither mechanism works well, so each curve dips. HEPA dips too, but its minimum is 99.97%, which at this scale is a flat line along the top.
MERV curves redrawn from the figure in Persily, A., Chapman, R., Emmerich, S., Dols, W., Davis, H., Lavappa, P., Rushing, A. (2007). Building Retrofits for Increased Protection Against Chemical and Biological Releases. NIST. Values are read off the published figure and show the shape of the relationship, not exact test results. The True HEPA line is my addition.
How does HEPA filtration work?
The graph above looks a little complicated, but if you’re interested, it’s very cool to see how HEPA filters remove 0.3 micron sized particles.
From top to bottom: the particle removal efficiency ranges from 0-100%.
Along the bottom of the graph: this shows the diameter of particles found in air, which ranges from 10 microns (the size of pollen) all the way down to 0.01 microns.
The curved lines on the graph are different MERV filters: MERV means Minimum Efficiency Reporting Value. MERV is a measure of how good an air filter is at trapping particles. You may have seen MERV 8 or 12 filters for your furnace, for example. The dip in the middle of each MERV curve happens right around 0.3 microns in particle size. Every level of MERV has a hard time capturing this size.
The nearly-flat line at the top of the graph is a true HEPA filter: for a filter to be called HEPA, it must capture 0.3 micron particles with 99.95% efficiency. HEPA filters easily capture particles 10x smaller and much larger than 0.3 microns, at about 100% efficiency.
What does HEPA mean? What is a true HEPA filter?
HEPA stands for High Efficiency Particulate Arrestance. For an air filter to be called a HEPA filter, it must be capable of removing at least 99.97% of particles that are 0.3 microns in size, like pollens, mold spores, bacteria, and others. HEPA filters easily capture particles 10x smaller and much larger than 0.3 microns, at about 100% efficiency.
Are HEPA-style or 99% HEPA filters the same as regular HEPA filters?
No! The terms HEPA-style, HEPA-like, 99% HEPA, and others, are not real HEPA filters. These do not filter particles with the same efficiency as HEPA filters, and may not filter small particles at all. HEPASilent is the exception so far; it is a more loosely woven, charged filter made by BlueAir and importantly, third party testing and its CADR numbers back up its effectiveness.
Is HyperHEPA or UltraHEPA better than regular HEPA?
No, these are marketing tactics. If you look closely, these filters are just H12, H13, or H14 HEPA filters. They all remove particles 100 times smaller than 0.3 microns— that’s the definition of HEPA. Due to complicated physics, 0.3 microns is the hardest size of particle to capture. It’s actually easier to capture particles both larger and smaller than this. Some of the brands listed above make the claim their HEPA filters are better than others, but I’ve decided not to hold it against them because their machines work really well in third party testing to protect people from dangerous particles and gasses. Big of me, I know! ;)
What is an ULPA filter?
ULPA filters are Ultra Low Penetration Air filters. They can actually capture even more particles than HEPA, but, they do not work as well as HEPA filters, because they are so tight, that air has such a hard time getting through them. They have a very low CADR (clean air delivery rate). They may appear better on first look, but they are not recommended, because they clean very small amounts of air.
True HEPA vs HEPA-Type vs ULPA Filters: what's the difference?
True HEPA: an air filter capable of removing at least 99.97% of particles that are 0.3 microns in size
HyperHEPA / UltraHEPA: usually just a true HEPA filter with marketing or branding attached. You can tell by looking at the specs, which will usually specify a standard true HEPA filter.
HEPA-Type / 99% HEPA / HEPA Style: not a real HEPA filter and not necessarily capable of capturing particles well
ULPA: ultra-low penetration air filters. Do not work as well as HEPA because so little air can get through to be cleaned.
PM2.5 vs PM10: Understanding Particulate Matter and Indoor Air Quality
What is Particulate Matter?
Particulate Matter is a fancy term for particles: tiny bits of solid or liquid floating in the air you breathe. You'll see it written as PM, and it's sorted by size (PM10, PM2.5, and PM1), because size determines how far into your body a particle can travel.
Where does particulate matter come from?
Indoors, particulate matter comes from pollen, dust, dust mite fragments, pet dander, and mold spores. It also comes from anything burning or heating: gas stoves, cooking oil, toasters, natural gas heaters, candles, fireplaces, wood stoves, and cigarettes. Sanding, sawing, and woodworking produce it too.
Outdoor sources get in through windows, doors, and ordinary gaps in the building envelope, which is how wildfire smoke, traffic exhaust, and industrial pollution end up in your living room even with everything closed.
Your body doesn't distinguish between sources. A particle from a scented candle and a particle from a wildfire are handled the same way once they're in your lungs. "Natural" sources of smoke doesn’t mean safe: wood smoke, wood dust, and even long-time exposure to cooking exhaust are all known human carcinogens.
What is PM 2.5?
PM2.5 is particulate matter smaller than 2.5 microns, which is roughly 30 times thinner than a human hair. These particles are small enough to travel past your airways, reach the deepest part of your lungs, and cross into your bloodstream. From there they circulate to your heart, your brain, and the rest of your body.
PM2.5 includes fine smoke particles, small mold spores, soot, airborne metals, and particles formed by chemical reactions of gases like sulfur dioxide (SO2) and nitrogen oxides (NOx).
Why is PM 2.5 bad?
Because it doesn't stay in your lungs. Larger particles get trapped and cleared. PM2.5 gets absorbed, and once it's in circulation it causes inflammation in tissue that never touched the air. PM 2.5 can increase the risk of heart attack and worsening of heart failure, increase ER visits, hospital admissions, and premature deaths, and is increasingly linked with dementia and Alzheimer’s Disease. It’s a major global health concern, both outdoors and indoors, and though indoor levels tend to be lower and are harder to track, can certainly be raised during daily cooking, wildfire smoke penetration through windows, burning candles regularly, and other indoor air pollution events.
What is PM10?
PM10 refers to particles below 10 microns and above 2.5 microns: pollens, molds, dust, and dust mite fragments. These are too big to reach your bloodstream, so their main effect is irritation of the throat and lungs. They can cause coughing, wheezing, and exacerbations of asthma, and reduce your lungs' ability to clear out bacteria and viruses.
Irritation can become chronic irritation, which can become inflammation, and inflammation over years is how a lot of disease starts. This is why particulate matter irritation is taken seriously for cancer risk.
What is ultrafine particulate matter?
PM0.1, or ultrafine particles, are smaller than 0.1 microns. They come from combustion, gas stoves, laser printers, and traffic. They cross into the bloodstream even more readily than PM2.5, and there's evidence they can reach the brain directly through the olfactory nerve. Most consumer air quality monitors don't measure them, and no US standard regulates them, which means they're a real exposure most people never see anything about.
How do you remove Particulate Matter from home?
With a true HEPA filter. All regular HEPA filters are capable of removing particles 100 times smaller than 0.3 microns at nearly 100% efficiency— it’s boring, but true. HEPA means High Efficiency Particulate Arrestance (or sometimes High Efficiency Particle Air).
Due to complicated physics, 0.3 microns is the hardest size of particle to capture. It's actually easier to capture particles both larger and smaller than this. So a HEPA filter removes ultrafine particles at close to 100% efficiency, which surprises people. It's boring, but true: the filter technology from the 1940s still outperforms every marketing term invented since.
Source control comes first, though. Run your range hood, use your exhaust fans that vent to the outside, don't burn things indoors, and use the HEPA to capture what’s left over.
Cooking Air Pollution: How Much PM2.5 Does Cooking Actually Create?
Cooking creates surprising levels of indoor air pollution, even when you don’t burn anything or can't see smoke.
I did a real-time air quality test: you can watch the video by clicking on the photo, or read my results here:
PM2.5 levels (fine particulate matter) spiked from 1 to 57 during normal dinner preparation (over 6 times the EPA's safe outdoor limit of 9 micrograms per cubic meter.) Simply sautéing chicken and boiling noodles generated dangerous levels of airborne particles linked to heart disease, asthma, and cancer risk. Even with a kitchen exhaust fan running on high and an open door, indoor air quality remained hazardous at 44 PM2.5 immediately after cooking. It took 30 minutes for particle levels to naturally drop back to 9, while VOCs (volatile organic compounds) remained elevated. This demonstrates why kitchen ventilation and air purifiers are essential for healthy indoor air: cooking pollution happens daily, even when your air looks clear. Running your range hood every time you cook and using a HEPA air purifier with activated carbon filtration can protect your family from these invisible cooking fumes and particulate matter.
Air Purifiers for Smoke
Is wildfire smoke particles or gas?
Both. Wildfire smoke is a mixture of particulate matter and gases. The particles are mostly PM2.5 and ultrafine, which is why smoke haze reaches your bloodstream so efficiently. The gas phase includes formaldehyde, benzene, acrolein, and carbon monoxide, produced when vegetation, homes, cars, and plastics burn.
This is why a HEPA filter alone isn't enough during a smoke event: the HEPA filter captures the particle half but no gas. You need activated carbon on the order of pounds for that.
What is the best air purifier for secondhand smoke?
The best air purifier for secondhand smoke has a true HEPA filter with an AHAM Verifide smoke CADR at least two-thirds of your room's square footage. It should also have more than 1 pound of activated carbon.
This is because tobacco smoke is a mixture of particles and gases, and an air purifier that only handles one leaves you breathing the other.
The particle half consists of fine and ultrafine particles: PM2.5 and smaller, which is why cigarette smoke reaches the bloodstream. A true HEPA captures these particles.
The gaseous half is nicotine vapor, formaldehyde, benzene, and acrolein. HEPA can’t capture these. Even something marketed as HyperHEPA or UltraHEPA that can capture particles down to 0.003 microns can’t capture these gases (scroll up to see a visual of gas vs. particle sizes.)
This is one of the few areas of air purification with real clinical evidence behind it. A double-blind randomized trial at Cincinnati Children's Hospital put HEPA purifiers with carbon (or identical sham units) in the homes of 225 children with asthma who were exposed to secondhand smoke. The children in homes with working units had 18.5% fewer unscheduled asthma visits over twelve months. A separate Johns Hopkins study in homes of pregnant women living with a smoker found significant reductions in indoor PM2.5 and in salivary cotinine, a biomarker of nicotine exposure.
Filtration reduces exposure, but isn’t a substitute for a smoke-free home. Also remember to use a fully sealed HEPA vacuum and wet dust weekly to capture any smoke particles that have settled into carpet, upholstery, or onto surfaces.
What is the best air purifier for wildfire smoke?
The best air purifier for wildfire smoke has a true HEPA filter with an AHAM Verifide smoke CADR roughly equal to your room's square footage and at least 1 pound of activated carbon:
AHAM Verifide means the CADR was tested by a third party and they can do surprise test checks on air purifier units anytime. A CADR without AHAM Verifide may be true, but it’s harder to know if the company is being honest. To find the smoke CADR, look at the technical specs on an air purifier’s page.
Smoke CADR is the best number to use here, not the overall CADR or pollen CADR. smoke stands in for the smallest particles (0.09 to 1 micron). That's the size range wildfire smoke lives in. A unit can post a strong pollen CADR and a weak smoke CADR, and pollen is the number brands prefer to advertise.
VOC filter: the best air purifier for wildfire smoke should also have at least 1 pound of activated carbon, which works as a VOC filter. This is where most wildfire recommendations stop, and from a health perspective, they shouldn’t. Wildfire smoke isn't just burning trees, it’s also burning homes, cars, wiring, insulation, and plastics, which produces formaldehyde, benzene, acrolein, and carbon monoxide. HEPA captures none of those gases. Only activated carbon, potassium, or zeolite adsorbs gases.
My recommendations are listed above, and here are some practical considerations:
Run the air purifier continuously, not just when you're in the room. Smoke keeps infiltrating through gaps even with everything shut.
Prioritize the bedroom since you spend the most time in it, and sleep is time for recovery.
Oversize on purpose. Rated coverage assumes an 8-foot ceiling and a sealed room, and a smoke is so small, it finds its way in easily.
Skip anything with an ozone generator or a non-defeatable ionizer. Ozone is a lung irritant, and adding it to smoke-stressed lungs makes things worse.
How VOC Filters Work
Gases, VOCs, and odors that pass through a VOC filter, AKA gas adsorbent, are caught, trapped, and affixed permanently to its surface.
A gram of activated carbon holds roughly 1,000 square meters of surface, folded into pores. A single pound works out to somewhere near 85 football fields of surface. This is why weight matters so much for how well a gas adsorbent works: fifteen pounds of carbon-zeolite has thirty times the surface of half a pound, so it holds thirty times as much before it fills.
What is adsorption vs absorption?
Adsorption describes something that happens on the surface; absorption describes something being fully permeated, like a sponge soaking up water.
What are VOCs?
VOCs are Volatile Organic Compounds. They volatilize, AKA are easily released from their sources into the air around them at room temperature. Here, "organic" refers to carbon-based chemicals, not organic in the sense of pesticide-free and healthy.
VOCs are gasses, and some, but not all, have an odor.
Are VOCs harmful?
Some VOCs, but not all, are harmful to health. Some of the well-studied harmful VOCs are:
Formaldehyde is the most well-known harmful VOC (it’s a carcinogen) and is found in furniture glues, new carpet, sealants, stains, and finishes on wood furniture or flooring, engineered wood and particleboard, paints, area rugs with synthetic backing and glues, and cleaning products.
Benzene is another VOC that’s a known human carcinogen: it causes leukemia, and the evidence behind it is strong. Indoors it comes from attached garages, tobacco smoke, fuel, and some paints and adhesives.
Toluene and styrene are also harmful. Toluene is a neurotoxicant found in paints, adhesives, and nail products. Styrene comes off polystyrene and some resins.
Not all are harmful: the scents plants release, essential oils, and food smells are all VOCs that are typically neutral or even good for our health.
Why are VOCs harmful?
VOCs can cause harm in two ways: by irritating your airways, and by passing through your lungs into your bloodstream, where they affect the rest of your body.
Airway irritation: This is the harm people expect. VOCs can contribute to asthma, allergy, and other lung issues, along with irritation of the eyes, nose, and throat.
Body wide: VOCs are gases. When you breathe in, they travel all the way down to the alveoli, the air sacs at the very end of your airways. This is where oxygen crosses the thin lung lining directly into your bloodstream. That lining is about two microns thick, and it is built to let small molecules through. It can’t tell the difference between oxygen and a VOC from a solvent. VOC molecules are very small, so they diffuse straight across. In rat studies, VOCs like trichloroethylene show up in arterial blood within a minute of the first breath. How much of any given VOC crosses over depends on the compound, but the pathway is short and fast. This is why VOCs can give you a headache: VOCs reach your head through your bloodstream.
Is the “new house smell” dangerous?
The "new house smell" is VOCs off-gassing into the air, and the smell itself is a poor guide to whether they are harmful. Most of what you smell is solvents and terpenes from fresh paint, finishes, furniture glues, and manufactured wood products. Those escape quickly and drop off quickly: total VOCs can fall 77% in the first 23 days.
Formaldehyde is different: it is one of the VOCs classified as a carcinogen, it decays far more slowly, and it is not always detectable by smell. In new homes, most VOCs fall to older-home levels within a year, while formaldehyde takes considerably longer. So a strong smell means ventilate, but no smell does not mean you are finished. Open windows are the fastest fix, and an air purifier with enough activated carbon helps when opening windows isn't an option.
Why do most air purifiers focus only on PM2.5 and not VOCs?
Purifiers focus on particles for three reasons:
First, particles are easily measurable and always harmful, whereas gases are hard to measure and a mixture of harmful and harmless. A basic sensor counts particles well enough to put a live number on a display, but most consumer VOC sensors are unreliable, expensive, and none can tell the difference between a harmful vs. harmless VOC. VOCs are not just one thing; they are thousands of compounds ranging from formaldehyde to the natural scent of pine wafting in from your backyard.
Second, the research on PM 2.5 is much stronger than it is for VOCs simply because PM 2.5 is a major outdoor air pollutant with decades of environmental research and funding behind it. There is a regulatory monitoring network for particles, so a study can estimate what hundreds of thousands of people breathed using nothing but their home address. Nothing like this exists for VOCs, partly because indoor measurements are difficult to research and especially because the complex mixtures of VOCs vary so much from home to home. Measuring them means putting instruments inside the house, one house at a time. So the gap between PM 2.5 and VOCs is about what is easy to study, not necessarily about what is safe, and the uncertainty is real. We do know a little: a systematic review of objectively measured indoor air found insufficient evidence that indoor PM2.5 affects adult asthma, and strong evidence that VOCs, especially aromatic compounds, are associated with increased asthma symptoms.
Third, there is no US standard for gas removal, so there is nothing to hold a company to. HEPA means something specific and testable: 99.97% of particles at 0.3 microns. CADR, the rating on the box, is measured with smoke, dust, and pollen, which are all particles. There is no CADR for VOCs here, and "carbon filter" has no definition behind it at all, so the same two words describe fifteen pounds of carbon-zeolite blend and a sheet of mesh with carbon dust sprayed on it. This is why I rate gas removal by carbon (or other adsorbent mineral) by weight.
Most air purifier brands focus on what has the most research behind it, what is easily measured and tested for. As awareness of VOCs rises, especially with the odors and VOCs associated with wildfire smoke, more are turning toward increasing their VOC adsorbent capacity.
Which is more dangerous, PM 2.5 or VOCs?
PM 2.5 has much more research backing up how dangerous it is, and more is coming out all the time. It is increasingly linked with diseases related to inflammation like dementia, heart disease, and other chronic illness. When it is in your house, like during wildfire events, opening the windows in a polluted city, and during cooking, burning fires or candles, it is dangerous and should be removed.
Do air purifiers remove VOCs?
Yes, if it has activated charcoal, zeolite, or another gas adsorbent working as a VOC filter. Gasses are not particles, and therefore cannot be captured by a HEPA filter. An adsorbent is used instead. Adsorption is a chemistry-based process that works when a gas clings to the surface of the adsorbent, where it stays trapped. Activated charcoal is very good at capturing a wide range of odors (also called VOCs) from the air.
A simple carbon cloth will not capture much, but if a pound or more of activated carbon is added, that increases the ability to adsorb odors. Sometimes, mineral mixtures are added to activated charcoal to increase the types of VOCs that can be adsorbed from the air. Potassium iodide, potassium permanganate, and zeolite are three different mixtures that are commonly added because each has a different pore size that can adsorb different chemicals better than charcoal alone. Zeolite is capable of adsorbing formaldehyde, which is important, because charcoal cannot do it on its own.
I also recommend removing VOCs from the source— purchasing low-VOC furniture and decor, and not using scented products (or choosing safer ones).
Do air purifiers remove odors?
Yes, if they have a meaningful amount of gas adsorbent, air purifiers can remove odors. Odors are combinations of VOCs.
What is the best air purifier for VOCs?
The best air purifiers for VOCs, smells, odors, and harmful gasses contain substantial activated carbon on the order of pounds (not just a cloth). Carbon holds gas molecules on its surface, and when it fills, the filter stops working. Half a pound of carbon vs fifteen pounds makes a huge difference in how long they last.
Formaldehyde is the exception:. Formaldehyde is a small, highly volatile molecule, and plain carbon holds it poorly. It still helps, but mineral media does better: potassium permanganate oxidizes formaldehyde instead of only holding it, and amine-treated carbon works by similar chemistry.
If a new build or new furniture is your reason for buying, look for a blend to capture both formaldehyde and the general VOC mixture.
Air Flow
Air Flow through Air Purifiers
An air purifier with excellent filters won't work if it's not capable of moving air through it, if it does so very slowly, or if the air escapes around the edges of an unsealed filter. The second component of what to look for in the best air purifier is its ability to circulate air through the filters for cleaning. Airflow determines how much of your room's air actually reaches that filter, and how often.
The problem is, the numbers can be really confusing and easily manipulated to seem better for you than they are. Understanding the difference between CFM, CADR, and ACH is really helpful.
What do CFM vs CADR vs ACH mean?
These measurements are about how much air flows through a purifier, how well that air is cleaned, and how long it takes that clean air to reach the whole volume of your room. CFM is the least useful number, CADR is helpful, and ACH is the most specific for your home.
CFM = Cubic Feet per Minute. Least useful. The CFM is how much air is pulled through a machine each minute. It says nothing about whether that air actually gets purified, and doesn’t consider the size of your room.
Calculation for your home: not very useful. You can look for at least 100 CFM for every 250 square feet of space, which works out to roughly 3 air changes per hour at standard 8-foot ceilings. But, this won’t tell you how well the air purifier actually works. Even if it has a true HEPA filter, it may not be sealed well. CADR is a much better indicator.
CADR = Clean Air Delivery Rate. Helpful. Cubic feet of clean air per minute an air purifier is capable of delivering. The CADR is the CFM multiplied by the efficiency of the filter. That means it captures both how much air moves and how much of the contaminants get removed from that air. CADR is tested in a lab in a sealed chamber, and brands will often show the results to prove their machines work well. The CADR is reported as three values: smoke, dust, and pollen (these are stand-ins for small, medium, and large particle sizes). A CADR tells you nothing about formaldehyde or other VOCs. But CADR is still useful because it catches bad purifiers that have an impressive-sounding CFM but a weak filter: in these, air moves through fast, but doesn't get clean, and the CADR comes out low.
Calculation for your home: look for an air purifier with a CADR two-thirds of your room's area. For example, a 20 x 15 foot room has an area of 300 square feet. So a CADR of 200 minimum would be ideal. (200/300 = 2/3). This rule assumes 8-foot ceilings. Note: CADR is reported in units of CFM, which you'll see on brand spec pages. That's correct, not a typo. Both are cubic feet per minute; CFM counts any air moved, but CADR’s CFM results count only the portion that came out clean.
ACH = Air Changes per Hour. How the machine’s CADR works for your specific room's total volume (square footage and ceiling height). This is something you have to calculate yourself; it’s not a property of the air purifier itself but how well it will work in your space, given how large a volume it is. It’s the most accurate way to predict how well a purifier will work in your space because it takes your ceiling height into account instead of assuming 8 feet.
Calculation for your home: ACH = (CADR × 60) ÷ (square footage × ceiling height). An air purifier with 4 to 5 ACH is ideal for regular use. Go to 5 or higher for allergies, asthma, or wildfire smoke season.
One important note: CFM and CADR (and therefore ACH) are calculated at max fan speed, which is often too loud and intense for a home. Choosing a model with numbers higher than you need may be best if you don’t plan to run your air purifier on its top speed all the time.
What does suggested room size mean for air purifiers?
Suggested room size is the square footage a brand says its purifier covers. It is not a standardized figure, which is the problem. Three separate assumptions go into it, and a brand can adjust any of them to make their purifier seem better than it really is. Some are honest, though! Here’s what to look out for:
How many air changes per hour: AHAM, the official highest standard, says 4.8 air changes per hour means an air purifier is doing a good job. Many brands use 4, some use 2, and some use 1 while still calling it "cleans."
Which CADR: smoke is hardest to catch, so the smoke CADR is the most telling. If a brand uses their smoke CADR, that’s the conservative and more impressive choice. Pollen is much easier to catch, so a pollen or averaged CADR is less impressive.
Ceiling height: brands assumes 8 feet for the volume of their suggested room size. If you have higher or vaulted ceilings, you have a bigger volume, and the air purifier won’t work for you as well as they state.
The same purifier can honestly be advertised at 525 sq ft or 2,520 sq ft depending on what details are use. Always check what air change rate a coverage claim assumes. If it isn't stated, assume it's an overstatement.
What does AHAM Verifide matter for CADR numbers?
Because anyone can run a CADR test, but only AHAM Verifide keeps checking.
CADR is a test method, and any brand can hire a lab to run it and publish whatever comes out. That's better than nothing and many labs are being honest while saving on the high costs that AHAM Verifide may impose on them. But, what the AHAM Verifide mark adds is everything that happens after that first test: air purifier units get randomly selected and retested annually, results are published in a public directory you can search, and a tested unit has to stay within 90% of its certified smoke and dust values and 80% of pollen to keep the mark. If the air purifier falls out of compliance, it loses the seal.
Without certification you get a number from one unit the brand chose to show you. It may be real and lasting, but may be just from one moment in time, with no directory to check it against and no consequence if performance drifts.
AHAM Verifide is voluntary and costs money, so some well-regarded brands skip it. Absence isn't proof of a bad machine, but just means the number is the brand's word. Look for multiple independent testing outlets or labs data when this certification doesn’t exist.
What does AHAM Verifide Room Size mean?
AHAM Verifide Room Size = Smoke CADR x 1.5, assuming an 8 foot ceiling.
Some brands advertise a suggested room size instead of a CADR. The 1.5 in the equation above comes from the 2/3 rule solved backwards: if a CADR should be 2/3 of your room's area, then the area a given CADR supports is that CADR × 3/2, or 1.5.
This also means you can work in reverse! Divide an advertised room size by 1.5 and you've recovered the CADR the brand chose not to lead with.
AHAM's convention is to use the Smoke CADR, the hardest size of particle to capture. It's the conservative choice, and it's the one that makes the numbers comparable across brands.
If a brand uses the Pollen CADR instead, the easiest size of particle to capture, that inflates the room size by roughly 30% off the identical machine. The room it now recommends is one the unit can't actually keep up with for smoke or fine particles.
*Verifide is spelled correctly; it's not Verified, but Verifide. Why? I do not know, but I’m guessing it’s probably a trademark registration quirk.
Common misleading specs used by brands
CFM in disguise: some brands and air purifier review sites will mistake CFM for CADR! A high CFM doesn’t mean it’ll have a high CADR. CADR is a much more useful number, which we get into next.
CADR in disguise: “suggested room size.” This is the same as CADR. Divide an advertised room size by 1.5 and you've recovered the CADR. Sometimes done this way by a brand if the CADR isn’t impressive, or sometimes just to be easier for you!
Pollen CADR instead of smoke CADR: One CADR published with no pollutant named, or a room size derived from the pollen number. If a brand shows one CADR instead of three, ask which one.
"Overall CADR." There's no such thing. CADR produces three values and they can’t be averaged because purifiers work differently on all three things. A single composite figure is either one of the three, or an average that hides the lowest one. Sometimes you’ll see a CADR published with no pollutant named. If a brand shows one CADR instead of three, ask which one it is.
A CADR above the maximum: The method tops out at 450 for smoke and pollen and 400 for dust, because the test chamber is only 1,008 cubic feet and a stronger unit clears it faster than the decay can be measured. A published smoke CADR above 450 isn’t real.
The one air change trick: "Cleans 2,520 sq ft in 1 hour" almost always means one air change, which removes about 63% of particles. The same machine's honest room size, at the 4.8 changes AHAM asks for, is roughly five times smaller. Watch for a big number in a parenthetical next to a small number in the headline.
Max fan speed only: Every published CFM and CADR is measured at the top speed, which is usually too loud to sleep next to. The speed you'll actually run is the one that counts.
Inherited numbers: A brand tests one model and reuses the figure across a series. Filter redesigns change CADR. If two models share a number, ask which one was in the chamber.
"True HEPA" as the only performance claim: It describes the media, but not how well the air purifier pushes air through it. A HEPA filter in a leaky housing lets air slip past the media.
What Good Quality Air Purifiers Remove
A good air purifier with all three filter layers (pre-filter, HEPA filter, and VOC filter) with good air flow is capable of capturing the following:
* Radon appears here only as its progeny, the solid decay products that deliver the dose. Radon gas itself is not captured by filtration, and it keeps producing progeny in the room, so source removal comes first. The two rows are the same element in two populations: fresh progeny form tiny unattached clusters, then stick to room aerosol to form the much larger attached fraction. HEPA removes the attached fraction well, which leaves proportionally more of the unattached fraction, and that one delivers more dose per unit. See my radon guide.
Bands mark which stage captures a pollutant first, not the only stage that can. A HEPA filter would capture pet hair too; the pre-filter simply reaches it first. The boundary between the HEPA and adsorbent bands is a matter of phase, not size: particles get filtered, gas molecules get adsorbed.
Common Air Purifier Gimmicks
What is a PECO air purifier?
PECO stands for PhotoElectroChemical Oxidation. It oxidizes micro-organisms, effectively killing them. This technology has been around for decades, but in 2016, was added to the Molekule air purifier. Unfortunately, it was found in multiple tests unable to filter out harmful particulate matter like PM 2.5 or other gasses nearly as effectively as regular HEPA filters can. The Molekule company was forced to retract these claims. While it is an interesting technology, with potential future applications, it remains just not as effective as regular HEPA filtration. The Molekule filter now has a HEPA filter and a PECO filter. This is a major and well-publicized version of healthwashing.
What is UVGI?
UVGI stands for Ultraviolet Germicidal Irradiation. This technology does have the ability to kill microbes, however, in most home air purifiers, the air flows by it too quickly, leaving inadequate contact time for it to be effective. UVGI also does not address the main issues in most homes, which are particulate matter and VOCs, rather than microbes.
What are air purifiers with ionizing technology?
Ionization is a very popular technology add-on for air purifiers. If they are strong enough, they emit ions, which stick to particles in the air, and cause them to become “heavier” and stick to items in the room. Sure, the air is cleaner temporarily, but now the particulate matter is settled on your stuff. Worse, if an ionizer is strong enough to do this effectively, it is also generating ozone, which is toxic to your lungs and causes inflammation.
Why are air purifiers with ozone generation unsafe?
Ozone, O3, is the free radical version of oxygen. It is highly reactive with particles in the air, and also highly reactive with cells in your body. Breathing in ozone can cause lung inflammation and respiratory issues.
Air Purifier Alternatives
Best Air Purifying Plants: Do They Actually Clean Indoor Air? What plants clean indoor air best?
680 of any plant you like! The 1989 NASA study that’s often referenced as proof that plants can purify the air is wildly overstated. While it’s true that plants can remove some VOCs and carbon dioxide, this study only applies to a small, sealed, space station style environment. In a regular house, you would need about 680 plants to replicate those results. See my short video about it here.
Are probiotic air purifiers worth it?
No. While I love the idea of probiotics incorporated into homes, this is not an effective way to remove fine particulate matter (PM 2.5) or VOCs, which can have serious consequences for cardiovascular, lung, and cognitive health, from your air. Until I see third party testing showing one of these can truly remove PM 2.5, I consider these a form of healthwashing, or wishful thinking.
Are moss air purifiers worth it?
No, unless you had the equivalent of 680 house plants worth of moss. The 1989 NASA study that’s often referenced as proof that plants can purify the air is wildly overstated. While it’s true that plants can remove some VOCs and carbon dioxide, this study only applies to a small, sealed, space station style environment. In a regular house, you would need about 680 plants to replicate those results. See my short video about it here.
Until I see third party testing of PM 2.5 reduction by moss, I consider moss purifiers a form of healthwashing. They may be pretty, and certainly aren’t doing harm, but aren’t protecting you from dangerous particles, either.
Are water air purifiers worth it?
No. These are a gimmick. Until I see third party testing showing that PM 2.5 can be captured effectively by water, I consider these a form of healthwashing. They aren’t protecting you from dangerous particles.
Air Purifiers for Mold, Radon, Pet Dander & Dust: What Works Best
Do air purifiers remove radon?
No, HEPA filters cannot remove radon gas directly, with two exceptions. But first: take care of the source. Radon gas comes from uranium decaying in the soil and rock under your foundation, and it gets trapped in your house. The only way to truly fix it is professional remediation. Radon is the second leading cause of lung cancer overall and the leading cause among people who have never smoked.
One semi-exception: radon gas itself does little damage on its way through you. Most of what you inhale gets exhaled before it decays. The danger is what it decays into: smaller, solid, radioactive metals. These are called radon progeny, or radon daughters: polonium-218, lead-214, bismuth-214, and polonium-214. They come out of the decay electrically charged, so they stick to whatever they touch, including particles already floating in your air. That means the PM2.5 a HEPA filter is very good at capturing can have radioactive metals hitching a ride on it. However, when a purifier strips the particles out of your air, the progeny have nothing left to attach to. The "unattached" fraction goes up, and unattached progeny deposit in your lungs far more efficiently than attached ones do. One field study in a high-radon home found the purifier cut total progeny by 33% while the unattached fraction rose 174%. Most of the research still finds a net reduction in dose, but it's smaller than the particle numbers suggest, and the EPA has never endorsed air cleaners as a radon strategy. Treat this as a small side benefit of a filter you're already running, not a reason to run one.
The second exception: activated carbon does adsorb radon gas. This is the whole basis of the charcoal used in radon test kits. VOC adsorbent containing zeolite might capture a very tiny bit of radon, too. But a carbon or zeolite bed against a continuous radon source from the ground doesn’t last long. Progeny also settle into your dust and onto your furniture, where no air purifier reaches them.
Read my guide to radon testing and recommended radon detectors here.
Can an air purifier help with mold?
Yes, an air purifier can help with mold in three main ways.
First, it can capture mold spores that are floating freely in the air, reducing the chances they will land and overgrow on a humid or damp area.
Second, if you’re allergic to the mold, it can reduce your exposure as it captures these spores.
Third, an air purifier with activated carbon or minerals can adsorb mold-associated VOCs and odors from the air, making it smell less musty during recovery from a mold problem.
Removing the source of mold is also very important; having a mold inspection and remediation done, or using a dehumidifier to prevent excess dampness are good ideas in conjunction with using an air purifier for mold.
Do I still need to dust with an air purifier?
Yes, but less often. Air purifiers are very efficient at capturing airborne dust, but are not strong enough to lift dust that settles on surfaces in your room off into the air.
Best Air Purifiers for Allergies: Do They Help with Symptoms?
Can air purifier help with allergies?
Yes, an air purifier can help with allergies in three ways.
First, it can trap large particles like pollen and pet hair on its pre-filter.
Second, an air purifier with a HEPA filter is great at capturing smaller particles like mold spores, dust mite debris, and even cooking or wildfire smoke particles that can irritate the lungs, nose, and throat.
Third, an air purifier with activated carbon or minerals can remove irritating VOCs from the air, which also contribute to allergy and asthma even more than PM 2.5 does.
Air Purifier Placement Guide: How Many Do You Need Per Room?
Where should air purifiers be placed?
Prioritize placing an air purifier in your bedroom, where you spend 1/3 of your life. Sleep is also when your body goes about repairing cells and healing, so having clean air and a healthy environment is important to support this process. If you can consider two air purifiers, placing one between the kitchen and living area is ideal because it will help capture cooking particles and odors and make the air in your living area, where you likely spend the second-most amount of time, safe.
How many air purifiers do I need?
I recommend considering both the square footage the air purifier is certified to clean, as well as the unique shape of your floor plan and home’s air flow. There’s a bit of an art to it. For example:
If you have an open floor plan, choosing an air purifier can be as straightforward as checking the CADR with your room’s dimensions (see above.) Air purifiers generally don’t have to work as hard to replace the air and get around walls or through door openings in this case.
If you have a house with lots of separation between rooms, you can still get one air purifier with a large square footage rating, but it won’t work as well. If budget is a concern, and you can only afford 1 air purifier, consider helping the air move between spaces a little better by using ceiling fans or other quiet fans to encourage air movement. If that’s not possible, you might consider two smaller air purifiers to focus on better on cleaning the air in each room separately.
If you’re not sure, I recommend using an air quality monitor placed in the room or area farthest away from your purifier to see if it’s purification reach is adequate for you. Relying on a purifier’s built-in air quality sensor isn’t useful in this situation, since it’s only sensing the air immediately around it. I have several highly accurate air quality monitors listed here.
How often do I need to change air purifier filters?
It will depend on the size and type of filter you have, and if you go through any poor air quality events like a wildfire or other thick smoke. Every air purifier brand and model will tell you how often the filter needs to be changed based on regular use, and will often have an indicator light go off. However, I recommend always replacing the HEPA and carbon filters after smoke events like wildfires.
How often do I need to turn my air purifier on?
Air purifiers are meant to be run 24/7 on their low setting, unless during times of high air pollution (wildfire, burning food indoors, or acute off-gassing from new furniture, for example.) If you want to save energy, turn air purifiers on whenever you get home, and start the one in your bedroom 20 minutes before you go to sleep so it has a chance to thoroughly clean the air.
How quiet of an air purifier should I look for?
I consider anything under 50 decibels (dB) to be quiet enough for bedroom use. For reference, 50dB is about the sound you’d hear in a quiet office, or coming from a quiet refrigerator. It’s generally considered a reasonable and safely quiet level for sleep, though of course your sensitivity may vary.
When sound is unwanted, and affects the health and well-being of people or other living creatures, it meets the definition of noise pollution. The EPA confirms that it’s not just an annoyance, but is as important to your health as other types of pollution are, like air or water pollution. Excess noise, especially at night, can actually contribute to heart attack, and have negative impacts on cardiovascular health, including high blood pressure.
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