Danny as been writing about air purifiers for 10+ years. He is a major fan of home technology, which makes him the perfect person to test and evaluate products for HouseFresh
Our verdict:
- Are you looking for an air purifier to help eliminate asthma triggers? You can’t go wrong with the mighty Levoit EverestAir.
- On the hunt for a powerful yet quiet air purifier that can be used during the night? Then you should go with the Smart Air Blast Mini.
- Are you on a tighter budget but still need to clean the air in a large space? Then the Levoit Core 600S is your best bet.
- Looking for a unit to be placed in a small room (up to 403 sq. ft. )? In that case, we recommend the Levoit Core 400S.
A study from 2020 showed that air purifiers could help asthmatic children to use less medication to keep their asthma symptoms in check as it can reduce the amount of PM2.5 particles in the air. However, not all air purifiers will help reduce symptoms — a study that used Dyson air purifiers could not significantly improve asthma control.
An air purifier can help reduce the number of tiny particles in the air from air pollution and dust mites that can aggravate asthmatic symptoms. True HEPA is very effective at removing these small particles but also needs a powerful fan to push enough air through the filter.
To keep asthma symptoms at bay, you must ensure that the air purifier you choose has a high level of air cleaning performance (CADR) so you can have at least 4-5 air changes per hour. The larger the room, the higher the CADR you will need.
| Why You Can Trust Our Recommendations It seems every big-name publication now has a list of “best air purifiers for X”… yes, even Rolling Stone magazine. Sadly, most of the articles you’ll read on these fancy sites are just overviews of the most popular units compiled by someone who has zero clue about air quality and who has done zero first-hand testing. But that’s not us. Here at HouseFresh, we take our air purifier reviews seriously and perform in-depth performance tests on all the air purifiers we include in our recommended lists. Every air purifier goes through the following as part of our in-depth reviews: 1️⃣ We fill our performance testing room with smoke from an incense stick that creates particle and VOC pollution. 2️⃣ We use a Purple Air Indoor sensor to record how long the air purifier takes to reduce PM1ug/m3, PM2.5ug/m3 and PM10ug/m3 particles. 3️⃣ We measure how much electricity each unit uses by tracking its energy consumption. 4️⃣ We measure noise levels in decibels across all the fan speeds to know how loud it gets. |
Armed with our test data, we can see which air purifiers would solve specific problems. When picking air purifiers for asthma, we ensured all of them had the following:
✅ True HEPA or higher HEPA grade — Pollen and PM2.5 from pollution are the primary triggers for asthmatics. So we only chose air purifiers that utilize this as their primary filter technology.
✅ High CADR: An air purifier with a low CADR score might be unable to remove all particulate pollutants quickly enough, so we have only included recommendations with a minimum CADR of 225 CFM.
✅ No ionization technology: While the ozone level is safe at 50 ppb for modern ionizer units like the Blueair HEPASilent, we avoided recommending those units in favor of mechanical filtration with zero byproducts.
The Top 3 Air Purifiers for Asthma
If you don’t have time to read our 3000+ word guide to the best air purifiers for those with asthmatic symptoms, these are the three air purifiers we currently recommend based on our own testing:
| 👑 BEST OVERALL | 📢 QUIET OPTION | 🛋️ FOR LARGE SPACES | |
|---|---|---|---|
| Levoit EverestAir | Smart Air Blast Mini | Levoit Core 600S | |
 |  |  | |
| AIR CLEANING SPEED ⚡ | 13 minutes | 17 minutes | 15 minutes |
| CADR 👩🔬 | 360 CFM (612 m3/h) | 435 CFM (740 m³/h) | 410 CFM (697 m³/h) |
| FILTER TECHNOLOGY 💨 | H13 True HEPA filter with activated carbon | H13 medical-grade HEPA filter | H13 True HEPA filter with activated carbon |
| MAX ROOM SIZE 📏 | Up to 558 sq. ft. | Up to 915 sq. ft. | Up to 635 sq. ft. |
| WEIGHT ⚖️ | 20.7 lbs (9.38 kg) | 59 lbs (26.8 kg) | 13.7 lbs (6.2 kg) |
| OUR REVIEW 🔍 | EverestAir review | Blast Mini review | Core 600S review |
| PRICE 💵 | $499.99 | $599.00 | $299.99 |
Last update on 2023-09-17 / Affiliate links / Images from Amazon Product Advertising API
Check out the six air purifiers for asthma that will help you to reduce symptoms in your home:
1. Best Overall: Levoit EverestAir
Having tested the EverestAir at HouseFresh, we were so impressed by its results that it quickly became one of our favorite units, surpassing expectations across various needs and uses.
When it comes to asthma allergens, the True H13 HEPA filter inside the EverestAir’s hood can filter fine particles as small as 0.3 microns and clean the air from asthma-triggering particles with impressive filtration efficiency.
Thanks to its high CADR score of 360 CFM and an efficient Auto Mode that adjusts fan speed based on pollutants using a built-in three-channel dust sensor, it can deliver constant fresh air with a good performance ratio to energy costs. Plus, it can do it fast. The EverestAir thoroughly cleaned our test room’s air in 13 minutes.
Although it’s a large unit, its new design is nothing like the bulky Core range; its sleek, futuristic aesthetic reduces its footprint. And it’s packed with smart features and app support.
What We Really Like:
👍 A washable pre-filter extends the filter’s life
👍 Has adjustable vent angles to direct the fresh air flow according to your preference
👍 It’s very quiet in slow fan speed mode
👍 Displays reading on indoor PM1.0, PM2.5 and PM10 levels on the control panel
What We Think Could Be Better:
👎 High initial price
👎 Only 2-year warranty
SPECS & FEATURES
| HouseFresh Rating: | ★★★★★ |
| Time to clean our test room: | 13 minutes |
| Air purifier technology: | 3-Stage Filtration (Pre-filter, H13 HEPA and activated carbon) |
| Recommended room size: | 558 sq. ft. |
| Clean air delivery rate (CADR): | 360 CFM (612 m3/h) |
| Dimensions (in inches / in cm): | 18.9L x 8.5W x 23.2H inches (48L x 21.6W x 58.9H cm) |
| Weight (in pounds / in kg): | 20.7 lbs (9.38 kg) |
| Noise level (low – high): | 24 – 56dB |
| Filter life: | 12-15 months |
| Manufacturer’s warranty: | 2 years |
| Estimated energy consumption: | $87.25 per year |
2. Quietest Option: Smart Air Blast Mini
The Smart Air Blast Mini is a giant air purifier with one significant advantage over the other units on this list — its ability to clean without exceeding 49dB is impressive, considering it cleaned our test room in 17 minutes.
If you need to keep a larger space free of particles that could aggravate asthma and need it to be as quiet as possible – the Blast Mini from Smart Air should be at the top of your list.
The Blast Mini is a large air purifier, so it might be overkill for those looking to keep a small bedroom free of particles, but this is perfect for those looking for large spaces.
I like that Smart Air allows you to choose a HEPA-only filter when you purchase rather than the integrated HEPA + carbon filter that we see with the Levoit purifiers.
What We Really Like:
👍 Pure mechanical filter, no ionizer
👍 HEPA H13 as standard with optional carbon filter – not required for particulate removal
👍 High performance with a low max sound output of 49dB
👍 Filter costs are fairly priced, considering their size and how often they need to be replaced
What We Think Could Be Better:
👎 High initial cost and energy usage
👎 No smart features like app support or auto-mode
SPECS & FEATURES
| HouseFresh Rating: | ★★★★☆ |
| Time to clean our test room: | 17 minutes |
| Air purifier technology: | H13 HEPA Filter |
| Recommended room size: | 915 sq. ft. |
| Clean air delivery rate (CADR): | 435 CFM (740 m³/h) |
| Dimensions (in inches / in cm): | 22.6L x 13W x 24.8H inches (57.5L × 33W × 63H cm) |
| Weight (in pounds / in kg): | 59 lbs (26.8 kg) |
| Noise level (low – high): | 36 dB– 49 dB |
| Filter life: | 33 months |
| Manufacturer’s warranty: | 1 year |
| Estimated energy consumption: | $277.70 per year |
3. Best for Large Spaces: Levoit Core 600S
The Levoit Core 600S had a ton of air-cleaning power and cleaned our test room in 15 minutes, which used to be the quickest we had seen before the EverestAir hit the scene. It also comes with many smart features, from app support to an auto-mode that adjusts fan speed depending on the amount of pollutants in the air.
The Core 600S, like the IQAir HealthPro, is a large unit, and while it contains far less carbon, it still uses pellets, which are the best form for picking up chemicals and odors.
The Levoit Core 600S has one of the best ratios of performance to $ spent with a CADR of 410 CFM for less than $300. While this unit is large, you can also utilize it in smaller bedrooms at a lower speed for a high level of air cleaning with a very low level of sound generated.
What We Really Like:
👍 Cleaned our test room in just 15 minutes
👍 Includes smart features like auto-mode and app support for Android and Apple
👍 Filter uses HEPA H13 and pelleted carbon
👍 Price to CADR ratio is one of the best on the market
What We Think Could Be Better:
👎 A large device and fairly dull design
👎 Made in China, build quality not as high as other units on this list
SPECS & FEATURES
| HouseFresh Rating: | ★★★★★ |
| Time to clean our test room: | 15 minutes |
| Air purifier technology: | H13 True HEPA filter with Activated Carbon |
| Recommended room size: | 635 sq. ft. |
| Clean air delivery rate (CADR): | 410 CFM (697 m³/h) |
| Dimensions (in inches / in cm): | 12.3 x 12.3 x 23.6 inches (31.3 x 31.3 x 60 cm) |
| Weight (in pounds / in kg): | 13.7 lbs (6.2 kg) |
| Noise level (low – high): | 26 dB– 55 dB |
| Filter life: | 6 months |
| Warranty: | 2 years |
| Estimated energy consumption: | $51.51 per year |
4. Best for Small Spaces: Levoit Core 400S
The Levoit Core 400S is the smaller brother of the 600S and has all the same smart features, including auto mode and app support. In our home lab performance test, this air purifier thoroughly cleaned our room of particulates in 33 minutes.
The Core 400S is much smaller than the Core 600S, making it much easier to live with in a smaller room. Size aside, this air purifier can still clean the air over four times an hour for a space up to 450 sq. ft. Levoit air purifiers’ popularity means you can find many generic filters for this unit for as low as $25 per filter.
For those with asthma, the Levoit Core 400S will easily keep your air free of dust mite particles and traffic pollution.
What We Really Like:
👍 Good ratio of performance to budget
👍 Powerful enough to keep air clean of particles up to 450 sq. ft.
👍 Same app and auto-mode that you find with the higher cost Core 600S
👍 Not too big, so it takes up less floor space than the larger Core 600S
What We Think Could Be Better:
👎 Not powerful enough for larger spaces — need to upgrade to the Core 600S
👎 Only 1-year warranty
SPECS & FEATURES
| HouseFresh Rating: | ★★★★☆ |
| Time to clean our test room: | 33 minutes |
| Air purifier technology: | H13 True HEPA filter |
| Recommended room size: | 403 sq. ft. |
| Clean air delivery rate (CADR): | 260 CFM (442 m³/h) |
| Dimensions (in inches / in cm): | 10.8L x 10.8W x 20.5H inches (27.4L x 27.4W x 52H cm) |
| Weight (in pounds / in kg): | 14.1 lbs (6.4 kg) |
| Noise level (low – high): | 24 dB – 52 dB |
| Filter life: | 6 months |
| Manufacturer’s warranty: | 2 years |
| Estimated energy consumption: | $39.95 per year |
5. Best For Long-Term Costs: Alen BreatheSmart Flex
The BeathSmart Flex is the simplified version of the flagship Alen 45i, but this version has no smart features or optional ionizer. In return, you pay much less for similar air cleaning performance; the Flex cleaned our test room in 34 minutes and only pulled 24.2 watts at its highest speed.
All Alen air purifiers have the possibility of a lifetime warranty when you purchase the filter subscription. When most air purifier brands have only a standard 1-2 year warranty, having something last a lifetime is impressive.
Another significant benefit for those with asthma is the filter options you can choose when you purchase. To get the most effective removal of particles that aggravate asthma, we recommend going for the B4-Pure Filter, which is 100% HEPA H13 and costs the least of all the filter options.
What We Really Like:
👍 Lifetime warranty is unique to Alen
👍 Competitive initial price (currently $100 off, so $249 but normally $349)
👍 Only hits 50dB at maximum speed and utilizes “Pink noise,” so easy to sleep with
👍 Filter choices mean you can customize with a filter that is best for your specific needs
What We Think Could Be Better:
👎 You don’t get any app support or auto-mode – this needs an upgrade to the 45i
👎 Lifetime warranty is only active if you have a filter subscription
SPECS & FEATURES
| HouseFresh Rating: | ★★★★☆ |
| Time to clean our test room: | 34 minutes |
| Air purifier technology: | H13 HEPA with an option for activated charcoal (Fresh, Odorcell and Heavy Smoke options available) |
| Recommended room size: | Up to 400 sq ft (4.5 ACH) |
| Clean air delivery rate (CADR): | 225 CFM 382 m³/h (Smoke: 191 / Pollen: 245 / Dust: 209) |
| Dimensions (in inches / in cm): | 25H x 15W x 8.5D inches (63.5 x 38.1 x 21.59 cm) |
| Weight (in pounds / in kg): | 15 lbs (6.8 kg) |
| Noise level (low – high): | 25 dB – 50dB |
| Filter life: | Every 9-12 months |
| Warranty: | Lifetime (with product registration & active filter subscription) |
| Estimated energy consumption: | $25.23 per year |
6. Best for VOCs: IQAir HealthPro Plus
Let’s get the tricky bit out of the way; this air purifier isn’t cheap.
At $899.99, it’s one of the most expensive air purifiers on the market but also one of the best. Made in Switzerland, each unit is tested before it leaves the factory. It utilizes its own patented HyperHEPA filter — perfect for eliminating asthma-causing pollutants, combined with a large, activated carbon filter with 5 lbs of carbon pellets.
You get a remote control but no smart features like an onboard sensor or app support. The IQAir Healthpro Plus has one of the largest HEPA filters we have seen and a very powerful fan; it removes all the pollutants in our test room in 25 minutes.
If you can afford it, this is the air purifier we recommend for those with asthma.
What We Really Like:
👍 Swiss made from one of the oldest brands in the air purifier industry
👍 The High-quality HyperHEPA filter is one of the largest we have seen used in a residential air purifier
👍 Large amount of carbon filtering with gases, VOCs and odors
👍 Wheels make it easy to move into different rooms as required
What We Think Could Be Better:
👎 Design is fairly utilitarian
👎 High price for initial purchase and filter replacements
SPECS & FEATURES
| HouseFresh Rating: | ★★★★☆ |
| Time to clean our test room: | 25 minutes |
| Air purifier technology: | HyperHEPA and V50-CELL gas and odor filter |
| Recommended room size: | 450 to 1125 sq. ft. |
| Clean air delivery rate (CADR): | 300 CFM (510 m³/h) |
| Dimensions (in inches / in cm): | 28H x 18W x 16D inches (71H x 38W x 41D cm) |
| Weight (in pounds / in kg): | 35 lbs (16 kg) |
| Noise level (low – high): | 25dB – 69dB |
| Filter life: | 4 years |
| Manufacturer warranty: | 10 years |
| Estimated energy consumption: | $165.04 per year |
Comparing Our Top Picks for Asthma: Air Cleaning Speed
As we test all our air purifiers in the same room, we compare different models and brands by looking at how long they took to reduce the PM1 level to zero:
| Our verdict: When it comes to air cleaning performance, the Levoit EverestAir wins by some distance with its impressive air cleaning speed of 13 minutes. |
Comparing Our Top Picks for Asthma: Noise Levels
We tested the sound levels for each of the air purifiers on our list at both the lowest and highest fan speed and used Flourish to visualize this data:
| Our verdict: The Alen BreathSmart Flex is the quietest air purifier on average, while the loudest is the IQAirHealthPro Plus. |
What to Look For in an Air Purifier to Help With Asthma
To get the right air purifier for asthma, you need to consider the following:
1. The Size of The Room
Bigger rooms will need bigger air purifiers, especially for those looking to use air purifiers to reduce asthmatic symptoms. HEPA filters do a great job of catching tiny particles, but for a larger space, you need to push a lot more air through them, which needs a bigger fan.
Below we calculated the room size for the asthma air purifiers we recommend above, assuming 8ft ceilings and aiming for around 4.5 air changes per hour.
| Air Purifier | Room Size | CADR |
| Alen BreatheSmart Flex | Up to 400 sq. ft | 225 CFM (382 m³/h) |
| Levoit Core 400S | Up to 450 sq. ft | 260 CFM (441 m³/h) |
| IQAir Healthpro Plus | Up to 600 sq. ft. | 330 CFM (560 m³/h) |
| Levoit Core 600S | Up to 700 sq. ft | 410 CFM (696 m³/h) |
| Smart Air Blast Mini | Up to 800 sq. ft. | 435 CFM (739 m³/h) |
2. True HEPA Filter
Unlike issues with odor or VOCs, the main issue for those with asthma is the tiny particles caused by traffic pollution or the waste from dust mites that enter the lung and cause allergic symptoms that trigger asthmatic episodes.
When choosing the best air purifier for asthma, you should prioritize units that feature a high-grade HEPA filter over those with activated carbon, which is better suited to issues associated with gasses and odors.
Some brands like Smart Air allow you to choose only a HEPA filter when you buy, which means you will get better performance than using an activated carbon filter at the same time, and you also save a little money on the initial purchase.
| 🍃 Alen also allows you to customize your filter choice and have one option perfect for those with asthma: the Pure Filter is 100% H13 HEPA and will most effectively remove tiny particles from the air. |
3. Budget
Many air purifier brands will provide room size recommendations based on 2 or even 1 air change per hour. If you take this recommendation for an issue such as asthma and allergies, you will be satisfied as you must aim for at least 4 air changes per hour.
Unless you have a tiny room, you should avoid a small air purifier if you want to successfully deal with asthma symptoms. While we love the Levoit Core 300, its CADR of 145 CFM is unlikely to bring relief to most average-sized American room sizes, and it’s why we suggest the higher-cost but more powerful Levoit Core 400S for those with asthma.
Those on a limited budget should keep their smallest room clean of particulates, as can be achieved with a smaller/lower-priced unit.
FAQs About Using an Air Purifier to Help Tackle Asthma
🤔 Do air purifiers help with asthma?
A study from 2020 showed that air purifier usage helped asthmatic children to reduce the amount of asthma medication they needed to keep their symptoms under control. Getting the right-sized air purifier that uses a HEPA filter can also help to reduce the amount of PM2.5 particles in your home air and reduce asthma flare-ups. You should also use a HEPA vacuum cleaner to regularly remove dust mite particles from mattresses and bedding.
🤔 How can I make my air better for asthma?
To improve air for asthma, you must reduce the pollutants that can trigger asthma attacks. These include Tobacco smoke, dust mites and outdoor pollution. An air purifier can remove particulate contaminants from the air if you have a HEPA air purifier that is the right size for your room. Another way to improve your air for asthma is to use a dehumidifier to ensure that your humidity level doesn’t exceed 50%.
For more tips, check out the CDC guide to asthma triggers.
🤔 What’s better for asthma — air purifier or humidifier?
In most cases, an air purifier is always good for asthma as it can help remove small particles in your home air, including traffic pollution and dust mites. If you have dry air, a humidifier might help and if you are in a damp location, a dehumidifier can keep humidity levels in a safe zone for asthma symptoms.
🤔 What kind of air is best for asthma?
A recent study showed that a temperature of 68 and 71°F and a humidity level between 30-50% is the best air condition for those with asthma. You will also want to keep the amount of PM2.5 particles as close to zero as possible, which HEPA air purifiers are great at.
Wrapping Up
Twenty-five million Americans suffer from asthma and while modern treatments have been great at reducing symptoms, there are still a lot of changes you can make in the home that can help without needing more medication.
Someone with asthma has a susceptible respiratory tract and is hyperresponsive to substances that may not impact others similarly. These substances, often called triggers, can spark asthma episodes and symptoms.
Many people with asthma understand the need for vacuum cleaners to keep dust levels minimal, but dust is not the only trigger… Some of the most common triggers include:
❌ Dust mites
❌ Pests (cockroaches, rodents)
❌ Pollen
❌ Mold
❌ Pet dander
❌ Smoke (from cigarettes, other tobacco or marijuana products, and fires)
❌ Outdoor air pollution, such as smog
❌ VOCs, chemicals or strong fumes
Using a HEPA-based air purifier that can effectively remove these tiny particles to keep air continuously clean and reduce asthma attacks.
| 🤔 Why should you deal with asthma triggers sooner rather than later? Asthma triggers vary for each person. However, when triggered, the muscles around the airways tighten, resulting in symptoms like: – Chest tightness or pain – Coughing – Wheezing – Difficulty breathing – Inability to breathe while lying down While asthma isn’t curable, symptom management is possible. Reducing or removing the trigger sources may be one of the most effective strategies. Using an air purifier that can effectively deal with allergens and air pollutants, reducing your exposure to asthma triggers in your home. |
As always, email me if you have any questions on how to get the most from using air purifiers for asthma.
Last update on 2023-09-17 / Affiliate links / Images from Amazon Product Advertising API