After having tested air quality monitors recently, we have been thinking more about indoor air quality, especially when using gas stoves, or during wildfire season. Here are our top picks for long lasting, ozone free, air purifiers to improve the quality of the air you and your family are breathing at home. Every purifier on this list is an ozone-free purifier, as certified by the International Association of Air Cleaner Manufacturers (IAACM).
There are plenty of excellent reasons to consider getting a home air purifier. A whole slew of studies have found that an air filter can:
- Vastly improve indoor air quality
- Reduce allergy symptoms
- Support improved respiratory and immune health.
HEPA filters are the gold standard. Even NASA uses HEPA filters!
Why you need an at-home air filter
Indoor air pollution has a dramatic effect on health, with links to:
- Cardiovascular disease
- stroke
- ischemic heart disease
- Cancer
- lung cancer in particular
- Respiratory diseases, including
- acute respiratory infections
- chronic obstructive pulmonary disease (COPD).
A World Health Organization (WHO) report found that a staggering 3.8 million premature deaths could be due to exposure to household air pollution every year.
See also: The best air quality monitors for home use
How can you improve indoor air quality?
There are several ways to reduce air pollutants at home. As always, prevention is best, meaning it’s wise to avoid bringing sources of air pollution into your home in the first place.
That means:
- Switching your gas stove for electric or induction
- Ditching your gas furnace in favor of a heat pump
- Installing a heat pump hot water tank instead of a gas model
- Choosing household products that don’t off gas volatile organic compounds (VOCs), including
Finally, an effective air filter is key to improving indoor air quality. A quality air filter can significantly reduce airborne allergens as well as pollutants like wildfire smoke.
In one study that took place over three to four seasons, researchers set up free-standing air filters and window air conditioners in the bedrooms of over a hundred kids with asthma and then monitored indoor air quality.
They found that air filters reduced particulate matter levels by 50%.
Similar results were seen in another study, where air filters reduced particulate matter by an average of 69-80%.
Air filters also filter out airborne infectious pathogens such as some viruses, bacteria, and fungi. Indeed, airborne droplets are responsible for diseases like tuberculosis, influenza, chickenpox, measles, and some types of herpes zoster.
Given the increase in globalization, as well as climate fires and other landscape fires in recent years, and the awful effects these have on indoor air quality, respiratory and cardiovascular health, it’s surprising that more public health officials haven’t emphasized the use of portable air cleaners.
How to choose the best air filter
For optimal air filtration, you’ll want to ensure four key things:
- Good air flow and ventilation in the room (and a suitably sized filter)
- An ability to filter out a range of particles, small to large, in different ways
- Easy maintenance and upkeep (and low-cost filter replacements)
- An ozone-free filter, as certified by the International Association of Air Cleaner Manufacturers (IAACM)
Let’s start with certifications and room size.
Certifications for air purifiers
As with home appliances like refrigerators and TVs, we recommend you choose an air purifier that is Energy Star certified. You may end up running your air purifier 24/7, making an energy efficient model better for your budget and the planet.
Energy Star models are around 40% more energy efficient than comparable models.
CADR
Look for an air purifier with an AHAM Verifide seal and a CADR. This certifies that the model has been tested by the Association of Home Appliance Manufacturers and that you can trust the CADR or clean air delivery rate.
CADR – Clean Air Delivery Rate – measures the volume of clean air a model produces when operating at its top level. So, a CADR of 150 for tobacco smoke filters air in such a way as to be the equivalent of adding 150 cubic feet of air clean of tobacco smoke every minute.
A higher CADR means greater efficiency and speed at filtering air. Be careful to check the CADR for different types of air pollutants, though.
If you’re mainly concerned about filtering out pollen, a model with a high CADR for formaldehyde may not be your best option, and vice versa.
Types of air purifiers
There are a few different options for at-home air filters, including:
- Whole-house filtration via your home heating, air-con, or ventilation system
- Free-standing air filters (portable air-cleaning [PAC] devices)
- A combination of these.
Most PACs use a fan to mechanically draw in and trap airborne pollutants and then blow out cleaned air. These are usually a good choice for rooms where the main problems are:
- Tobacco and/or wildfire smoke
- Pollen
- Dust mites and their feces
- Animal allergens
- Exhaust particles.
Some PACs are noisy, though, and they can also be energy-hungry.
A good quality air filter typically filters air at several stage, using a:
- Pre-filter
- Carbon filter
- Antibacterial filter
- HEPA filter.
The latter is usually found in hospitals and clinics and uses mechanical filtration to remove airborne particulates. HEPA filters adhere to standards requiring a minimum 99.97% efficiency for removing particles measuring 0.3nm (1/83,000 of an inch) in diameter or larger.
To conclude, I highly recommend choosing a multistage air purifier with a HEPA filter. This can be a freestanding unit or a filter that works with your existing HVAC. Ideally, any air filter or purifier will also have a pre-filter and carbon filter to trap larger particles and any troublesome gases.
Mechanical (HEPA) filters typically need replacing every 6 months to a year to keep performing well. These can cost anywhere from around $80 to $200, depending on the make and model.
An activated carbon filter needs to be replaced every 3 months as it gets saturated faster. These filters typically cost around $50.
Replacing all of your filters on the recommended schedule helps the machine to perform at its best, which makes it far less likely to malfunction and require more serious maintenance or replacement.
Brands to consider
There’s a lot of hype around air purifiers, so it pays to look at third-party testing of any efficiency claims.
In one test of six commercially available brands, Hacker and Sparrow looked at three electrostatic precipitators and three HEPA filters. Of these, one offered no benefit at all, with this result also seen in another study. The lemon was the heavily marketed Ionic Breeze Quadra – clearly an air filter to avoid. Of the six units tested, the HEPA filters worked best, while the electrostatic devices were less efficient.
The best performer of the six units was a stationary model designed for use at the headboard end of a bed to provide filtration to the “sleep breathing zone” (SBZ). This unit nearly completely removed all particles. The other two HEPA filters also performed well. Unfortunately, the authors did not provide the names of the models they used in this study, opting instead for a general comparison between HEPA and non-HEPA models.
Some of the most well-regarded brands for air purifiers include:
- Blueair
- IQAir
- Honeywell
Alen, Idyllis, and Kenmore also make decent models, but the three companies above consistently score well in independent testing.
The best ozone-free air filters
Below, we list our top-rated air filters – all of our selections are ozone free. You can read about our unique research process here.
IQAir MultiGas GC Air Purifier
Highlights: One of the best air purifiers on the market, capable of assisting with VOCs, wood smoke, tobacco smoke, exhaust fumes, smog, and more.
- Ozone free
- Wheels make it easy to roll across a room
- Geared towards VOCs, smoke, and air pollutants
- Can filter indoor air pollution from gas stoves
- Big unit is difficult to move up and down stairs
- Component parts can become dislodged after moving which can make the unit noisy
- Expensive
If you’re mostly concerned about VOCs, wood smoke, tobacco smoke, exhaust fumes, or smog, the IQAir MultiGas GC is for you. This one contains a high-efficiency micro particle pre-filter with 32 sq. ft. of HEPA H11 Class material, providing particle removal down to 0.003 microns (95%). It also features a filter containing 12 lbs. of granular activated carbon and impregnated alumina.
And, just to really seal the deal, the post-filtration sleeves contain 5.4 sq. ft. of electrostatically charged fibers to capture fine dust, making it a great option if you’re a woodworker.
This air filter is recommended for rooms of up to 285 sq. ft. for premium gas filtration or up to 1,125 sq. ft. for general-purpose gas filtration.
Our team lives in urban environments and mountain towns that are prone to smoke, which caused us to choose the IQ Air Multigas.
The Multigas has also proven useful while living in a home with a gas stove, which massively impacts indoor air quality.
While the model itself is great, it does require replacing the canisters every 9-10 months, which feels very wasteful.
Given that the canisters have a charcoal substrate, we wonder if there’s scope for IQ Air to offer substrate replacements, allowing users to re-use the canister. This would dramatically reduce plastic waste with this product.
IQAir Atem Personal Air Purifier
Highlights: A great personal air purifier option that fits on a desk, headboard, or nightstand. Lightweight and portable – great for travel!
- Ozone free
- Top of the line technology
- Portable
- Dual voltage – can be used internationally
- Only filters small 32 sq. feet
If you’re looking for a personal air purifier for use at your office desk or on your bedside table, the IQAir Atem is a fantastic choice. This filter creates a clean air zone around you and is quiet, draft-free, and ozone-free. I also love that this air filter is lightweight (6 lbs!) and truly portable; you can quickly take it apart and pop it in your carry-on or suitcase. And, handily, it’s dual voltage, so can be used in most countries.
This air-filter contains 32 sq. ft. of HyperHEPA™ filtration media, providing particle removal down to 0.003 microns (99%). It also contains a PureJet diffuser that allows for optimal positioning whether you’re sitting, standing, or sleeping. So, set it up for your sit-stand desk and have wonderfully clean home office air.
BlueAir Blue Pure 511
Highlights: Stylish, effective, lightweight, very affordable, and super quiet air filter.
- Compact and inconspicuous (also looks chic!)
- Effective performance for such a small filter
- Very quiet
- Lights automatically go out
- Lightweight enough to put on a shelf (4 lb.)
- Energy efficient and Energy Star qualified (just 3.5 w)
- Very affordable (under $100!)
- Washable pre-filters available in different colors
- Not as effective as the IQ Air in third-party testing
- Best for smaller spaces of 180 sq. ft. or so (though can handle up to 432 sq. ft.)
- Replacement filters are expensive
- No child lock (and they’ll love playing with the single tap button)
The Blueair Blue Pure 511 is a top choice for an ozone-free air purifier. It works best for smaller spaces such as the nursery, home office, or dorm room and is very efficient for its small size.
The 511 is also very, very quiet. I only just noticed that my local library uses this model in its meeting rooms. That’s how inconspicuous it is! Even on high, this filter is just 49 dB. On its quietest setting, it’s just 24 dB.
As well as being quiet, this model is also efficient, clearing at least 99.97% of airborne particles (to 0.1 microns). Oh, and it looks great and has a washable pre-filter you can change to suit your aesthetic.
Honeywell HPA300 Air Purifier
Highlights: A workhorse in regular conditions, with a turbo mode for extra relief on super smoky days.
- Ozone-free
- Affordable
- Lightweight
- Filters 465 sq. feet
- Could be more energy efficient
The Honeywell HPA300 is another good budget option for air purifiers. It’s pretty light (just 16.8 lbs) and has a carry handle, so is easy to move as needed and can be used on a table or the floor. This model is a true HEPA filter that is efficient at removing dust, smoke, and pollen even at its lowest speed. And it’s a touch quieter than the Blueair, making it a good option for in the bedroom at night or for a home office while you’re taking calls.
The Honeywell HPA300 really punches above its weight too. It’s great for large rooms up to 465 sq. ft. and captures up to 99.97% of airborne particles as small as 0.3 microns. It has a very impressive CADR of 300 for smoke, so is a really good choice for places at risk for climate fires as well as for anyone living with a smoker.
The controls on this model are easy to use and there’s a filter indicator to let you know when to change the mail filter. It also has a programmable timer!
As for the downsides, the Honeywell costs a little bit more to run than the Blueair Blue Pure but is Energy Star certified. Overall, this one is a good choice for a home office or bedroom. If your budget stretches to it, though, consider the IQAir Atem Personal Air Purifier for small spaces instead.