Alen a350 Air Purifier Review

Updated 2020

The Alen A350 was an air purifier that was first sold in 2010, if you already have one of these units then congrats on keeping your unit running for 10 years. You will also be happy to know that you can still buy filters for these units:

Alen (BF25A-Silver HEPA-Silver Replacement Filter for A350 and A375 Air Purifiers, 1-Pack
  • Silver-Ion Technology protects the filter against growth of harmful bacteria and microbes
  • Creates an allergy and asthma friendly environment by removing dust, pet dander, mold spores and pollen from the air
  • Provides pure, breathable air by capturing VOCs (Volatile Organic Compounds) from cleaning products, personal care items and other household materials
  • Pre-Filter layer extends the life of the filter
  • Eligible for Alen's convenient AutoShip Filter Plan with FREE lifetime shipping

Sadly the Alen A350 is no longer for sale but there are a number of new Alen units that you might be in interested in that have a similar specification:

1. Alen BreatheSmart Flex

Alen BreatheSmart FLEX Air Purifier,H13 True HEPA for Large Rooms up to 700 Sqft, SleepScore Validated, Dust, Mold, Pet Odors + Smoke, White
  • FRESH AIR: Recommended for dust, dander, allergens, fur, household odors, all while preventing the growth of mold and bacteria. The Fresh Filter is equipped with 0.66 lbs of activated carbon to absorb harmful airborne particles including smoke, household chemicals, VOC’s, and more.
  • TRUE HEPA FILTER - Includes a Medical Grade H13 True HEPA layer that removes 99.99% bacteria, aerosolized viruses, and airborne particles larger than 0.1 micron. True HEPA filters last 3-5 months longer than standard filters.
  • CLEANS AIR FAST: Cleans 700 SqFt every 30 minutes, twice as fast as key competitors on Turbo speed. Sleek design fits in any space from small to extra large bedrooms, living rooms, offices, nurseries, kitchens, and basements.
  • SLEEP MODE: Features a “lights out mode”, press the power button once and the lights turn off. SleepScore validated and users feel more rested upon waking.
  • LOW ENERGY CONSUMPTION: 50 Watts on Turbo speed. Lowest setting will use less than 50 cents a month in electricity.

With a CADR rating of 230 for pollen, the breathsmart flex would be the A350 for the modern era. This unit comes with the same Alen lifetime guarantee so you can expect this air purifier to keep performing beyond 2030!

2. Alen BreatheSmart T500 

Alen BreatheSmart T500 True HEPA Air Purifier for Home, Office, Bedrooms, up to 500 Sqft. Eliminates Germs, Bacteria, Mold, Odors, while Filtering Allergens, Dust, Pollen, Pet Dander in White
  • PURE AIR ANYWHERE: Cleans up to 500 SqFt of air every 30 minutes on high speed. It's ultra-portable, 25% smaller than comparable tower air purifiers, yet 63% more effective in real home tests.
  • ANY ROOM SIZE: Fits perfect in any space from small to large rooms, living rooms, bedrooms, dorms, offices, bathrooms, nurseries, and kitchens.
  • KILLS GERMS AND MOLD: Recommended for allergens, dust, dander, fur, pollen, and household odors PLUS germs, mold spores, and bacteria. HEPA Silver filter has a compound that eliminates airborne bacteria, germs, fungi, and viruses including the flu.
  • SIMPLE TO USE: Quickly adjust settings with a touch of a button. Easy-to-change TRUE HEPA filters that capture 99. 97% of airborne particles down to 0. 3 microns.
  • CERTIFIED: Energy Star Certified and Certified Ozone Safe by the California Air Resources Board (CARB).

This unit is a little cheaper but still has a CADR rating for dust of 159 so less powerful than the A350 but can often be found for less than $250 so significantly cheaper. This is a low priced unit but still comes with the Alen lifetime guarantee.

The following article is our original review of the Alen A350 Air Purifier from 2010:Alen a350 Air Purifier 

PRICE = $399 (

Before we start to dig deep into the pros and cons of this particular purifier. It’s worth having a look at what consumers at the major retailers think of this purifier. Most large internet retailers allow consumers the ability to provide a rating for their purchase. I use this rating as an initial way to quickly gauge the performance of an air purifier.

Review SiteRating
Amazon.com4 Stars (30 reviews)
Epinions.com5 Stars (8 reviews)
Wize.com4.5 Stars (77 reviews)
Shopping.com4.5 Stars (8 reviews)
Air Purifiers America4.5 out of 119 (10 user reviews)

The Alen a350 purifier has achieved favourable scores across a wide range of sites. I

Note: Air Purifiers America has business connections to Alen so we need to take their scores less seriously than the other more independent retailers.

The video below will take you through a sample of reviews so you can get an idea of what people like/dislike about it:

The next step we take for this air purifier review is to dig a little deeper into what the experts are saying about this purifier:

1. Air Purifier Power – Written By Ed Sherbenou – URL


Air-Purifier-Power Rating: 82, good


  • In recent assessments by this A-350 eliminated 98% of the contaminants in the device and 97% of the contaminants within the room.
  • The A 350 purifier is great at airborne dirt and dust and plant pollen elimination, yet is also competitively cost-effective costing under $300..
  • So the projected CADR (for basic comparability to mid priced store bought models without having chemical substance blocking capability ) is 203.
  • The manufacturer guarantees 95% of purchases are going to be delivered within Twenty four hours, and also features a straight forward return policy.


  • Significant gas and smell elimination is really a necessity if health benefits can be envisioned: Models with actual carbon VOC ability position higher.
  • Alen A350 air purifier sound amounts will be over normal: 36 decibels(A)on low setting, 65 decibels(A)@214cfm on highest setting. 65 decibels(A) isn’t the loudest, but 214cfm is fairly weak for that amount of noise.
  • The organization doesn’t sell direct, yet drop ships air cleaners marketed by merchants.

2. URL


Provides some reservations that the A350 should only be used in smaller rooms.


  • Highlights that this particular purifier can be mounted on the wall
  • States that the replacement filters  are relatively cheap
  • Mentions that the A350 comes with a Lifetime warranty


  • Talks about how come consumers mention that the power supply causes a “humming” sound
  • Indicates that this air purifier should only be used in smaller rooms

CADR Results:

Sadly the A350 has not undergone a CADR test so we can not provide this results for this test. Thankfully Ed at air-purifier-power has worked out that this purifier has a similar ranking to a CADR ranking of 203.

The Alen A350 therefore has an estimated score of: 203 CADR Ranking

Technology Used:


1.HEPA Filter

The Alen A350 uses one combined HEPA, carbon, and pre-filter in one unit. The only issue this raises is the price as the purifier requires this combined filter to be changed every six months. Currently, you can purchase the A350 filters on for $49.99 which is not too bad but bear in mind that you will need to replace these twice each year – so it’s $100 per year. If I compare this with other purifiers that use Lifetime HEPA such as the Honeywell 50250-N, the A350 is considerably more costly to run.

2. Ionizer Function

One of the nice benefits of the Alen A350 is that it comes packaged with an inbuilt non-ozone ionizer unit. Normally I would suggest that people steer clear of ionizer only units but when combined with a strong HEPA filter it can help improve cleaning efficiency. The ionizer unit will charge the surrounding particles with a negative charge which will mean that these particles are heavier and thus picked up more easily by the HEPA filter. Negative ions have also been shown to imbue of sense of well being but this still has not been confirmed by scientific studies. If you are not sure about the ionizer then you can easily disable the function using the on-off switch at the top of the unit.

Power Consumption

The A350 has a Energy Star Rating which should reduce it’s electricity to just pennies per day.

Addressing the Sound Problem

Some reviews have mentioned that the A350 has a whining sound when running. In tests we came across no such noise and believe that this whining sound was down to broken air purifiers. On the highest setting the A350 creates a noise level of 65 dB which is relatively  loud. In the video below I show the Alen a350 working at each different sound level so you can evaluate if it’s too loud for your home. 

Whilst the purifier is loud at the level 5 setting, it’s unlikely that you would need to leave it at this level for much time. I am quite happy with the sound output at the lowest level and so would not find a problem sleeping with it running in my bedroom.


This purifier provides a significant amount of cleaning for the small price of just under $400. It can be used in medium-sized rooms (400 square feet recommended) and has the ability to successfully remove all types of particles. My only issue with this purifier relates to the cost of replacement filters ($100 each year) and the lack of VOC capabilities.

When comparing with other purifiers you should make sure that you take into account the $100 a year cost as some Lifetime HEPA filters will work out far cheaper in the long-run and may outweigh the initial extra cost.

The Alen A350 air purifier is currently the highest-rated purifier in my medium range ($200-$700) purifiers and I give it a 5 star rating.

If you want to move away from Alen for your next air purifier, then check out my latest recommendations:

1.Best for Most People – LEVOIT Pet Edition
LEVOIT Air Purifiers for Home Allergies and Pets Hair, H13 True HEPA Filter for Bedroom, 24db Filtration System with ARC Formula, Remove 99.97% Odors Smoke Dust Mold Pollen, Core P350, Gray
  • Genuine Replacements: Search for "p350-rf" or "B087R7ZFPB" for levoit 3-in-1 customized pet filter with ARC Formula to ensure excellent performance
  • Perfect Gift for Pet Families: Ideal for pet allergies, improve your air quality and help you and your pets relieve allergic symptoms such as sneezing, coughing, sinuses and heavy breathing. Ozone-free, approved by CARB, ETL listed and CA PROP 65 certified
  • High Powered: The Vortexair Technology offers an increased CADR of 141 CFM / 240 m³/h, handily covering rooms as large as 219 ft2 (20㎡) and refreshing the air 5 times per hour, perfect for bedroom, living room, dining room or pet room
  • H13-Grade True HEPA Filter: Reduces up to 99.97% of harmful air pollutants, smoke, pollen, mold spores, dust mites and other allergens as small as 0.3 microns from the air. This new fine non-woven fabric pre-filter is more effective than other common pre-filters at capturing floating hair, pet fur, pet dander, dust, fibers, lint
  • Sleep Mode & Timer: The QuietKEAP Technology keeps noise levels as low as 24dB. Set a timer for 2, 4, 8, or 12 hours, then turn off the display light to enjoy a perfect and undisturbed night of sleep. The pet lock button prevents your pets from tampering with any of the other buttons or settings

2. Budget-Friendly – $75ish Hamilton Beach TrueAir
Hamilton Beach TrueAir Air Purifier for Home or Office with Permanent HEPA Filter for Allergies and Pets, Ultra Quiet, Black (04386A)
  • High Performance Hepa Grade Filter: Captures 99% of pet dander, dust, dust mites, pollen, and mold / mildew spores as small as 3 microns from the air.
  • Easy to clean: Allergen reducing air purifier has a permanent Hepa-grade filter that easily vacuums clean.
  • Compact, stylish design: Allergen reducing air purifier is perfect in the office or in rooms up to 160 square feet
  • Versatile air care that fits anywhere: Position the unit vertically or horizontally to best fit in your bedroom, den, nursery, hallway or living room at home or at the office.
  • Quiet and powerful: Use whisper clean for extra quiet operation at night, the medium setting or the quick clean setting for more powerful air cleaning.

3. Winix 5500-2 – For those with bigger rooms
Winix 5500-2 Air Purifier with True HEPA, PlasmaWave and Odor Reducing Washable AOC Carbon Filter
  • True HEPA filter captures 99.97% of airborne pollutants; dust mites, pet dander, pollen and other allergens as small as 0.3 microns
  • Washable AOC Carbon Filter, made from activated carbon granulars for removal of household odors. Decibels 27.8 dB
  • PlasmaWave acts as a permanent filter to safely break down odor, allergens, chemical vapors and other pollutants with no harmful ozone
  • Smart Sensors gauge the air and our Auto Mode adjusts the fan to filter the air as needed; with a sleep mode for silent night time operation
  • CADR rated for 360 square feet room size. Suitable for medium and large rooms; kids bedrooms, family rooms and kitchens

4. Coway Airmega 400 – If you need the very best or the largest space (whole apartment/small house)
Coway Airmega 400 Smart Air Purifier with 1,560 sq. ft. Coverage
  • Coway Airmega 400 room air purifier is designed to accommodate large room sizes up to 1,560 square feet and cleans the air at least two times per hour when used as recommended.
  • Coway Airmega Max2 filter—combined activated carbon and True HEPA filter—captures and reduces up to 99.97% of 0.3 micron particles in the air, including pollen, pollutants and other allergens. It also reduces volatile organic compounds by more than 99% and reduces fumes such as NH3 and CH3CHO. Includes washable and permanent pre-filter to catch larger dust particles.
  • Coway Airmega’s pollution sensor communicates indoor air quality testing in real-time. The brightly colored LED ring lets you know how clean or dirty your indoor air is, every minute of the day.
  • Coway Airmega has five fan modes: Smart, Sleep, Low, Medium and High. Noise level is nearly silent at lower speeds. Max noise at highest setting is 43.2 dB.
  • Coway Airmega is a smart, energy efficient air purifier with a three-setting smart mode to adapt to its surroundings. Fan speed automatically adjusts based on the room’s air quality and lighting conditions to improve air quality.

Last update on 2020-10-20 / Affiliate links / Images from Amazon Product Advertising API

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