Best Air Purifier 2018 – Reviews and Buyers’ Guide

We offer our visitors detailed air purifier reviews & air purifier ratings.

We only cover the trusted home air cleaner brands which have proven to be the best ones over many years of work in the industry and directly with customers.

Our air purifier reviews are based on the vast amounts of reliable information we collect from manufacturers websites as well as a large number of other internet sources, ex., personal websites of air purifier users and sites of retailers which conduct air purifier tests and collect feedback from their customers.

There is a certain degree of consensus among experts and users with allergy-related conditions about which air purifier brands can really deliver great results. So you will probably see similar reviews on other purifier sites as well.

In spite of the seemingly abundant number of air purifier reviews and ratings on the web, we still found that either a lot of such information is fragmented and incomplete, or opinions expressed are not totally objective.

If you are new to this subject, we highly recommend that you first read our Home Air Cleaners article which provides an excellent overview of different types of technology commonly used in air purifiers, so that you can choose the right one for your own needs.

Below is a summary of air purifier reviews which we cover on this site. Follow the links for each specific model to learn more.

Please feel free to send us any feedback – our new visitors will really appreciate it.

Air PurifiersAboutTechnology
IQAir HealthPro PlusIQAir HealthPro Plus removes the widest possible range of air pollutants including both particles and gases & odors.
It is arguably the best HEPA home air cleaner in the world.
It covers an area of up to 900 sq. ft.
  • Pre-filter PreMax catches at least 99% of all particles at 5 microns
  • Main HyperHEPA particle filter eliminates at least 99.5% of ultra-fine particles down to 0.003 microns in size
  • V-5 Cell gas & odor filter contains 5 pounds of activated carbon & activated alumina, and utilizes adsorption & chemisorption processes to eliminate gaseous pollutants
IQAir HealthProIQAir HealthPro targets the widest possible range of particles but not gases & odors.
It can be upgraded to add a V-5 Cell gas & odor filter at a later stage.
It covers an area of up to 1000 sq. ft.
  • Pre-filter PreMax catches at least 99% of all particles at 5 microns
  • Main HyperHEPA particle filter eliminates at least 99.5% of ultra-fine particles down to 0.003 microns in size
  • Possibility of using a V-5 Cell gas & odor filter
IQAir HealthPro CompactIQAir HealthPro Compact removes the widest possible range of particles but not gases & odors.
It features a smaller design than IQAir HealthPro Plus and IQAir HealthPro, to make it suitable for use in smaller apartments and offices.
IQAir HealthPro Compact covers an area of up to 900 sq. ft.
It cannot be upgraded to add a V-5 Cell gas & odor filter at a later stage.
  • Pre-filter PreMax catches at least 99% of all particles at 5 microns
  • Main HyperHEPA particle filter eliminates at least 99.5% of ultra-fine particles down to 0.003 microns in size
Blueair 650EBlueair 650E removes a wide range of particles and a very modest amount of gases & odors.
It can be upgraded to include optional SmokeStop filters for a thorough filtration of gaseous pollutants.
It covers an area of up to 698 sq. ft.
This model offers a wide range of electronic user controls.
  • Combination of electrostatic and mechanical HEPA-style filtration of particles
  • Electrically charged particles cling on to the filter media - HEPASilent filters or SmokeStop filters
  • HEPASilent filters remove at least 99.97% of all particles 0.1 microns in size
  • Optional SmokeStop filters, on top of particle-removing capability, contain significant amounts of activated carbon for dealing with gaseous pollutants
Blueair 603Blueair 603 removes a wide range of particles and a very modest amount of gases & odors.
It can be upgraded to include optional SmokeStop filters for a thorough filtration of gaseous pollutants.
It covers an area of up to 640 sq. ft.
This model is similar to Blueair 650E but does not offer a full range of electronic user controls
  • Combination of electrostatic and mechanical HEPA-style filtration of particles
  • HEPASilent filters remove at least 99.97% of all particles 0.1 microns in size
  • Optional SmokeStop filters, on top of particle-removing capability, contain significant amounts of activated carbon for dealing with gaseous pollutants
Blueair 550EBlueair 550E is similar to Blueair 650E and offers a wide set of electronic user controls.
But it covers a smaller area of up to 605 sq. ft.
It is able to remove a wide range of particles and a very modest amount of gases & odors.
Blueair 550E can be upgraded to include optional SmokeStop filters for a thorough filtration of gaseous pollutants.
  • Combination of electrostatic and mechanical HEPA-style filtration of particles
  • HEPASilent filters remove at least 99.97% of all particles 0.1 microns in size
  • Optional SmokeStop filters, on top of particle-removing capability, contain significant amounts of activated carbon for dealing with gaseous pollutants
Blueair 503Blueair 503 is similar to Blueair 603 and does not offer a full range of electronic user controls.
It removes a wide range of particles and a very modest amount of gases & odors.
Blueair 503 can be upgraded to include optional SmokeStop filters for a thorough filtration of gaseous pollutants.
It covers an area of up to 580 sq. ft.
  • Combination of electrostatic and mechanical HEPA-style filtration of particles
  • HEPASilent filters remove at least 99.97% of all particles 0.1 microns in size
  • Optional SmokeStop filters, on top of particle-removing capability, contain significant amounts of activated carbon for dealing with gaseous pollutants
Alen A350Alen A350 air purifier targets a wide range of particles and a very modest amount of gases & odors.
It can use other types of filters which are specially enhanced with powerful media for more serious gas & odor control.
This model features a compact design and is wall-mountable.
It covers an area of up to 400 sq. ft.
  • Washable pre-filter catches larger particles
  • Main HEPA Plus filter removes smaller particles - at least 99% of all particles 0.3 microns in size and larger
  • Activated carbon removes some modest amounts of gases & odors
  • Optional built-in ionizer generates negative ions which are beneficial for human health
Alen T300Alen T300 air purifier features a tower design, with the control panel at the very top of the unit.
This model targets a wide range of particles and a very modest amount of gases & odors.
It can use other types of filters which are specially enhanced with powerful media for more serious gas & odor control.
It covers an area of up to 300 sq. ft.
  • Washable pre-filter catches larger particles
  • Main HEPA Plus filter removes smaller particles - at least 99% of all particles 0.3 microns in size and larger
  • Activated carbon removes some modest amounts of gases & odors
  • UV light reduces populations of biological pollutants
  • Optional built-in ionizer generates negative ions which are beneficial for human health

IQAir HealthPro Plus

IQAir HealthPro Plus air purifier has been widely recognized by experts and users alike as arguably the best home air purifier currently present on the market.

Why?

The answer is simple:

IQAir HealthPro Plus produces exceptionally clean air which is a major contributor to good health.

It is the only air purifier that has been clinically proven to relieve allergic asthma.

There is also a lot of feedback from IQAir HealthPro Plus’ actual users that this home air cleaner does indeed relieve asthma and allergy symptoms.

Many independent third-party tests have also verified the results claimed by the manufacturer.

The American Lung Association has chosen IQAir as an educational partner to raise awareness on indoor air quality issues.

The Hong Kong Hospital Authority has selected IQAir systems as the only portable air filtration solution for SARS patient rooms to protect patients, stuff and visitors.

Healthcare institutions in Northern America, Europe and Asia have been using IQAir air cleaners to control the spread of SARS, MRSA, TB and the bird flu.

This is to mention just a few accolades earned by the company.

In other words, IQAir HealthPro Plus is as good an air cleaner as it gets.

No other home air cleaner has yet been proven to produce better results.

The same cannot be said about other “home appliance” manufacturers which usually add air purifiers as an additional line of business when they see a high profit potential.

Summary

So let’s summarize the main features of this excellent air purifier.

Air Pollutants
Targeted for Removal
Results:
Particles Actually Removed
  • Particles generally found in indoor air: dust, tobacco smoke, viruses, bacteria, pollen, molds, dust mite parts, animal dander
  • Gaseous pollutants & odors including volatile organic compounds (VOCs)

That includes the whole spectrum of air pollution usually present in indoor air.

  • 99.97% of all particles 0.3 microns and larger – which is a minimum requirement for a conventional HEPA filter
  • 99.5% of all particles down to 0.003 microns – a particle size which is 100 times smaller than a conventional HEPA requirement, and 10 times smaller than a virus
  • highly efficient at removing gases and odors – which can be as small as 0.0003 microns in size
Technology Used

PreMax large capacity particle pre-filter. Control of coarse and fine dust particles. 25 square feet of wet laid non-woven, mini-pleated glass microfiber. Certified to remove at least 99% of particles 5 microns and larger in size.

V5-Cell wide-spectrum gas & odor filter. Control of wide range of gaseous chemicals. 5 pounds of activated carbon & activated alumina impregnated with potassium permanganate.

HyperHEPA cleanroom-grade high-efficiency particle filter. Control of very small particles such as allergens, bacteria and viruses. 40 square feet of wet laid glass microfiber, mini-pleated with solvent-free separators. Certified to remove at least 99.95% of particles 0.22 microns in size on lower speeds and at least 99.5% of particles 0.16 microns in size on higher speeds.

Covers an area of up to 900 sq. ft

Design & Construction Quality
  • Air is drawn in through two arches at the bottom of the unit, passes through three filtration stages (pre-filter, gas & odor filter, main filter) and is expelled out of the top of the unit
  • No shortcutting, which means saving the unit’s cleaning capacity for purifying polluted air from the room and not allowing the freshly purified air to get re-drawn into the unit and go through the filtration process again
  • No internal air leaks, which means the highest possible efficiency of air filtration
  • Independent filter replacement means not having to buy and replace all the filters simultaneously, in a bundle, even when some of them may not have been fully used up; being able to change filters individually means bigs savings for the owner in the long-run
  • 6 fan speeds, to provide users with as much flexibility as possible
Other Functionality
  • Ozone-free operation
  • Filters’ long lifespans produce savings for the owner in the long-run
  • Reasonable noise levels commensurate with excellent volumes of clean air delivered at different speeds
  • Extensive user controls – programmable time, filter-life monitor, remote control
  • Moderate energy use
  • Respectable 5-year long warranty period
Price Range
  • Air Purifier Unit – from $899 (most online retailers) to $939 (direct from the manufacturer)
  • PreMax replacement pre-filter – from $59 (most online retailers) to $65.50 (direct from the manufacturer)
  • V5-Cell replacement filter – from $89 (most online retailers) to $95.50 (direct from the manufacturer)
  • HyperHEPA replacement filter – from $189 (most online retailers) $195.50 (direct from the manufacturer)

Who Should Consider Getting IQAir HealthPro Plus

IQAir HealthPro Plus is one of the best and most popular home air cleaners on the market.

It has the best user feedback judging by online user ratings submitted to most popular shopping websites and specialty internet shops.

Don’t take our word for it – do your own research and you will most likely come to the same conclusion.

IQAir HealthPro Plus is highly recommended for people with asthma / allergy issues.

It produces great results and, although quite a significant investment at the start, it offers a very reasonable cost of ownership (i.e., cost of replacement filters).

It is highly recommended even if you don’t have any health-related issues – it will keep your indoor air clean and healthy for the years to come.

IQAir HealthPro

IQAir HealthPro air purifier utilizes powerful HyperHEPA technology
to produce highest-quality clean air for indoor environments.

IQAir air purifier to be a green product.

IQAir HealthPro offers the same super-efficient particle-removal HEPA technologies as IQAir HealthPro Plus but without the gas & odor filter (V-5 Cell).

This model can easily be upgraded to IQAir HealthPro Plus with an option of adding V-5 Cell at a later stage.

IQAir HealthPro targets the widest possible range of particulate pollutants usually present in indoor air.

The smaller the particles, the more dangerous they are to human health because they can enter the blood stream and damage the body directly via blood supply.

IQAir HealthPro does not target gaseous pollutants like IQAir HealthPro Plus but can be upgraded at any time as required.

Who Should Consider Getting It

If you have a mild sensitivity to air pollution and want to remove the vast majority of particulate pollutants from your indoor air, then you should certainly give IQAir HealthPro a go.

If, however, at a later stage you will find out that this may not be enough for your needs, you can always upgrade to IQAir HealthPro Plus and add the V5-Cell gas & odor filter to your unit.

IQAir HealthPro is one of the best air purifiers on the market and is highly recommended for anyone who wants to keep their indoor air clean and healthy for years to come.

IQAir HealthPro Compact

IQAir HealthPro Compact features the same super-efficient particle-removal HEPA technologies as its big sisters IQAir HealthPro Plus and IQAir HealthPro but in a smaller design to make it suitable for use in smaller apartments and offices.

IQAir HealthPro Compact covers an area of up to 900 sq. ft.

Lets have a quick look at what makes it such a good air cleaner.

Compared to the IQAir HealthPro Plus model, IQAir HealthPro Compact does not target gaseous pollutants and cannot be upgraded to include the gas & odor filtration option at a later stage.

Who Should Consider Getting It

IQAir HealthPro Compact is a smaller version of IQAir HealthPro and is suitable for small apartments and offices. It covers an area of up to 900 sq. ft.

For bigger spaces, you may want to choose IQAir HealthPro which has the same technical parameters as IQAir HealthPro Compact but covers an area of up to 1000 sq. ft.

Blueair 650E

For the first time in the history of the world,
every human being is now subjected to contact with dangerous chemicals,
from the moment of conception until death.

Rachel Carson, 1962

Blueair 650E Air Purifier ReviewThanks to its ability to improve home environment as well as eco-friendly manufacturing practices and end-life recyclability, we consider this Blueair air purifier to be an excellent green product.

Blueair purifiers have gained wide international recognition as being among the best air purifiers in the world. They are designed and manufactured in Sweden where they also won prestigious design awards.

Blueair 650E model is a highly sophisticated air purifier which covers an area of up to 698 sq. ft.

It combines, uniquely, the use of the electrostatic particle-charging process with the mechanical HEPA-like type of filtration.

Blueair 650E belongs to a series of electronic air purifiers in Blueair‘s product line (identified by letter E at the end of its name).

This Blueair purifier produces truly clean air, and this claim is backed by extensive positive feedback from experts and users alike.

Here we discuss the features that make this air purifier such a success.

Air Pollutants Targeted For Removal

Blueair 650E‘s main targets are tiny particles (or particulate pollutants) which are commonly found in indoor air.

These particulate pollutants include dust, pollen, mold spores, animal dander as well as bacteria and viruses.

We know that the smaller the particles’ size is, the more dangerous they are to human health. So the smaller the size of the particles your air purifier is able to filter out, the better.

Blueair 650E achieves the removal of particles with its HEPASilent filtration technology.

It also makes an attempt to remove some gaseous pollutants as well, by incorporating quite a small amount of active carbon.

However, it does not appear to offer a serious level of filtration for gases & odors which would be expected, for example, by people with pollution-related health conditions such as allergies and asthma.

Gaseous pollutants are generally much smaller than particulate pollutants (meaning even more dangerous to our health than particles), and are therefore a real challenge to remove.

For more sensitive individuals who do need an advanced level of filtration for gases & odors, Blueair 650E does offer optional SmokeStop filters with a significant amount of activated carbon to trap this type of air pollutants.

Learn more about the dangers of large and small air pollutants in our Home Air Cleaners article.

Technology Used & Results

To state it again, Blueair 650E‘s core technology that achieves such excellent results is the combination of electrostatic and mechanical HEPA-style filtration of airborne particles.

It is called HEPASilent technology.

The name comes from the fact that Blueair purifiers which use this technology are very quiet, especially when compared to equivalent purifiers by other brands.

Let’s try to make sense of it all.

Stage 1 – Electrostatic Particle-Charging Process

During the first stage of its operation, Blueair 650E uses electrostatic brushes to charge the particles with negative ions in a special ion chamber.

Such electrical charge makes it very easy for the charged particles to cling on to the filter media afterwards and stay there, while the particle-free air will flow back into the room.

Stage 2 – HEPASilent Filters

Blueair 650E HEPASilent FiltersBut before the air flows back into the room, it needs to go through the second stage of the process which involves three HEPASilent filters. They are the actual filter media that electrically charged particles get attached to.

Each of HEPASilent filters purify the air progressively, in a three-stage structure.

Here is how it works.
Each filter has three layers of ultra-thin fibers which come in three different sizes.

The first layer traps particles of larger sizes such as pollen and dust and the second and third layers trap smaller particles, ex. bacteria and viruses.

HEPASilent filters are made of non-toxic polypropylene material which readily accepts electrically charged particles.

Polypropylene is waterproof and does not need to be treated with chemical-based bacteriostats to prevent the growth of bacteria inside the filter.

When operating at its lowest speed, HEPASilent technology achieves the removal of at least 99.97% of all particles 0.1 microns in size.

This is far above the minimum HEPA requirement for removing 99.97% of particles which are 0.3 microns in size.

You can find out more about HEPA technology here.

This HEPASilent particle-removing technology is enhanced with a very modest amount of activated carbon for a light removal of some gases & odors as well.

Stage 2 (Optional) – SmokeStop Filters

SmokeStop Filters

For people with pollution-related conditions Blueair 650E offers an advanced level of filtration for indoor gases & odors.

If you want to utilize this option, you can simply get three SmokeStop filters instead of standard HEPASilent filters.

SmokeStop filters combine both particle– and gas– removing capability just like the standard HEPASilent filters.

They are absolutely identical to HEPASilent filters in terms of their particle-removing capacity.

But they are much more powerful for dealing with gaseous and chemical pollutants.

SmokeStop filters contain significant amounts of activated coconut-shell carbon impregnated with potassium iodide, phosphoric acid and potassium hydroxide.

This set-up has proven to be highly efficient at dealing with this type of air pollutants.

CADR Rating

Blueair has voluntarily submitted their air purifiers for CADR testing and received CADR ratings for each model.

CADR stands for Clean Air Delivery Rate.

It has been developed by the Association of Home Appliance Manufacturers (AHAM) as a method for measuring an air purifier’s performance.

CADR is the volume of filtered air produced by an air cleaner, measured in cubic feet per minute. It takes into account an air cleaner’s ability to remove only particulate air pollutants completely disregarding gaseous pollutants.

The particles measured by CADR are dust, pollen and tobacco smoke 0.1 to 11 micron in size. The maximum CADR ratings awarded by this system will be 450 for pollen and tobacco smoke and 400 for dust.

Blueair 650E has the following CADRs for each measured pollutant:

  • Tobacco Smoke = > 450
  • Pollen = > 450
  • Dust = > 400

As you can see, Blueair 650E has managed to achieve the highest CADR ratings possible.

This of course means that it is the best performing air purifier among all the purifier models (by other companies) which have been measured for CADR.

A word of caution here.

You can use CADR to compare air cleaners which only deal with particulate pollutants.

CADR does not measure filtration of gases & odors, and is therefore useless for comparing those air purifiers which aim to provide advanced levels of filtration for this type of pollutants.

It is almost certain that CADR will not help individuals with asthma and allergy conditions make the right buying decision.

Learn more about why CADR is flawed here.

There are many excellent air purifier brands (that actually do target gaseous pollutants) that decided to stay away from CADR ratings.

Blueair 650E is, in many ways, an outstanding purifier. It easily competes with most other purifiers including those targeting particles as well as gaseous pollutants. You will only need to read some user and expert feedback widely published on the internet to come to the same conclusion.

But please bear in mind that CADR ratings are not the best way to compare different air purification systems even though Blueair promote it as such on their corporate website.

Design & Construction Quality

Blueair 650E features a boxy design, with a fan located at the bottom of the unit and filters attached to the unit’s side walls and its top.

Here is an actual step-by-step process of air purification.

The fan draws air from under the bottom of the unit as well as from small areas located at the bottom of each of the unit’s side walls, front wall and back wall.

Step 2
The air passes through an ionization chamber where it gets electrically charged with negative ions.

Step 3
Once charged, the air travels through each of the three filters (two on the sides and one at the top). As a result, the particles “carried” by the air get attached to the filters and stay there.

Step 4
Clean air is then pushed out of the top areas of the side walls as well as from the very top of the unit itself.

Some Design Advantages

The important advantages of Blueair 650E‘s design over that of competing electrostatic air purifiers are:

  • Blueair 650E‘s system charges the particles themselves as they pass through an ion chamber and then get attached to the filter media.
    Most other electrostatic air purifiers charge the fibers of their filters rather than the particles directly. This filters’ charge will weaken over time and significantly reduce the efficiency of their systems.
  • Blueair 650E requires little maintenance, including a filter replacement a couple of times a year and an occasional cleaning of the unit’s internal parts.
    This is different from other electrostatic air purifiers which require frequent cleaning of their particle-collector plates – or their efficiency will fall dramatically in a short period of time.

Some Design Disadvantages

The main disadvantage of this design is its lack of a pre-filter.

Many competing high-quality air purifiers use pre-filters to catch larger particles – both to protect the unit’s internal parts from dirt and to extend lifespans of their main filters.

This, for example, is the case with IQAir air purifiers.

Blueair have developed an otherwise excellent design for their air purifiers and, surely, they could have included a pre-filter.

The main reason they may have decided against the use of pre-filters was to achieve higher CADR ratings.

So while Blueair 650E has reached the maximum possible CADR ratings, it did have to sacrifice some user convenience and filters’ longer useful lives (and this does increase the costs associated with more frequent filter replacements).

Other Issues

The housing of Blueair 650E units is made of galvanized steel rather than petroleum-based plastics. This guarantees the durability of the system that customers can use safely for many years to come.

Blueair 650E‘s smart design also guarantees ozone-free operation which we discuss further down in this article.

The three-stage filter design ensures that filters do not experience any loading or clogging and keep their efficiency for longer periods.

Other Functionality

Ozone Safety Issues

Some readers may be concerned about the safety of this purifier’s electrostatic process.

As we know, many other lower-quality electrostatic air cleaners usually produce unhealthy amounts of ozone as a by-product of their operation.

Ozone is a lung irritant, and people (especially sensitive individuals) are generally advised to avoid contact with it altogether.

Blueair 650E‘s highly efficient design does not produce ozone during its operation. In fact, it has even been shown to reduce ozone levels in the air it purified.

Here is how the company explains this process:

Ionization [i.e. electrical charging] does produce trace amounts of ozone, a gas known to irritate compromised lung tissue. Blueair systems use a very low electrical current to minimize ozone production and a sealed steel housing surrounding the ionization chamber to keep ozone contained. For more protection, our activated carbon filter adsorbs any ozone particles that may escape from the encapsulated ionization chamber.

In this respect, we consider this ozone-free use of the electrostatic process a real achievement by Blueair which has proven elusive for so many other companies.

Filters’ Lifespans

Blueair 650E‘s major design shortcoming – lack of a pre-filter – becomes most apparent when there comes a time to replace filters.

Its HEPASilent filters’ lifespans are quite short compared to competing high-quality purifiers.

The company’s recommendation is to replace filters at least twice a year.

That means each filter’s useful life-time is only around 6 months.

This compares unfavorably to IQAir‘s pre-filter’s lifespan of 6 – 18 months, and the main HEPA filter’s service of 2 – 4 years.

Having said that, users report that polypropylene filters can be vacuumed for longer service life.

Very Low Noise Levels

This is the area that Blueair 650E excels at.

It is obvious the company has put a lot of effort into making its products as quiet as possible, and users certainly appreciate that.

Low noise levels are a big advantage that Blueair purifiers, with their blend of electrostatic and mechanical HEPA technologies, have over purely HEPA cleaners.

Traditional HEPA purifiers have to use powerful fans to push air through true HEPA filters – and, naturally, that produces noise as well.

Blueair 650E‘s combination of electrostatic and mechanical filtration is almost perfect in terms of the quietness of its system’s operation.

It has 3 fan speeds.

For each of its fan speeds, Blueair 650E offers the following noise levels (measured in decibels (db)), and volumes of clean air produced (measured in cubic feet per minute (cfm)):

  • Speed 1: 88 cfm @ 35 db
  • Speed 2: 285 cfm @ 40 db
  • Speed 3: 490 cfm @ 71 db

We should, of course, point out this model’s outstanding rates of clean air produced per minute of operation.

Compared to industry leader’s IQAir HealthPro Plus best clean air production rate of 240 cfm @ 71.9 db at its highest speed (speed 6), Blueair 650E beats it by at least two times and delivers 490 cfm @ 71 db at its highest speed (speed 3).

It appears that, thanks to its quiet operation, this air purifier is very popular among customers buying it specifically for use in the bedroom.

Digital User Controls

BlueBlueair 650E User Controlair 650E features an extensive set of digital controls which carries several major benefits:

  • remote operation of the unit
  • option of using timers
  • display of data on your unique domestic air quality
  • use of electronic pollution-level sensors for choosing the correct speed setting
  • use of auto mode setting
  • filter replacement indicator

Some of the most impressive digital-control features that have been widely welcomed by experienced users are:

  • Automatic detection of pollution levels – both for particles and gaseous pollutants, and
  • Use of auto mode function to automatically set the right speed depending on current indoor pollution levels

Apart from these advanced functions, Blueair 650E offers all the convenience of operating the unit remotely, using the timers and a filter replacement indicator.

Environmental Issues

Now the environmental aspects of Blueair air purifiers are something that I totally admire these people for.

I am not yet aware of any other air purifier that can match the environmental standards Blueair have managed to achieve with their products.

This is how the company explains the environmental impact of its products.

  • Blueair systems are long-lasting.Their housings are made of steel which is a lot more durable than plastic. This guarantees many years of service for customers.
  • Blueair systems are made of Earth-friendly materials.They utilize only non-toxic materials, from filters to the exterior finish. All their components are recyclable at the end of their useful life.If filters, for example, do end up in a landfill, they will only release carbon dioxide and water.
  • Blueair filter media use no chemical additives.
    Blueair‘s polypropylene filters are water proof and therefore do not require any chemical-based bacteriostats or mold inhibitors which could be harmful if later released into the environment.
  • Blueair systems are energy efficient.
    Actually, they are as energy-efficient as it gets. Blueair 650E‘s power usage is between 35 and 120 watts depending on the fan speed.
    That is the trick – to achieve high efficiency of air purification with lower power use. Blueair does it with excellence and better than many other purifiers.

Alen A350 Air Purifier

Alen A350 In RoomWe offer you a review of the Alen A350 air purifier on our website because we consider it to be a good-quality, affordable product which strives to be genuinely green.

Alen A350 air purifier has only been around since mid-2000s but quickly gained popularity in the market for particle-removing home air cleaners.

According to their manufacturer Alen Corp, Alen air purifiers aim to offer something that’s been notably missing in other brands of mass-produced air purifiers:

  • quality of service delivered
  • better design
  • affordability, and
  • environmental sustainability

Alen A350 air purifier is a HEPA purifier – it is expected to remove airborne particles at least 0.3 microns in size and larger.

This machine does not remove any significant amounts of gases & odors which are much smaller in size than particles.

It features a sleek boxy design with a digital display right at the top of the unit, and is wall-mounted to save space in the room (or can be placed on the floor).

Alen Corp draws our special attention to the fact that this product has an affordable price ($399 as of Sept. 2010) as compared to other premium air purifiers, and delivers high results at the same time.

According to the manufacturer, the Alen A350 can cover an area of up to 800 sq. feet, and 400 sq. feet for “optimal performance“.

However, some online allergy-specialty retailers recommend a room size of 281 sq. feet for this machine.

So what about Alen A350‘s environmental credentials?

Alen Corp offers a lifetime warranty for all their models (unprecedented in the industry) as they state that they want “none of our air purifiers to ever end up in a landfill“.

Let’s discuss these and other points in more detail.

Air Pollutants Targeted For Removal

Airborne Particles

Alen A350 Air Purifier Review 1Alen A350 air purifier specifically aims to remove airborne particles, ex. dust, pollen, pet dander, mold etc.

Airborne particles range roughly between 100 microns and 0.003 microns in diameter. For comparison, the average size of a human hair is 100 microns.

Alen A350 is a true HEPA air purifier.

HEPA has been widely accepted as a quality measure which guarantees a high level of air purification for consumers.

HEPA air purifiers are required to remove at least 99.97% of airborne particles which measure @ 0.3 microns in diameter.

So we understand that Alen A350 air purifiers remove at least this amount of airborne particles. This seems to be confirmed by the information provided by Alen Corp in its User Manual for this model.

At the same time, it is not clear why the tech details on the manufacturer’s website for this model refer to the removal of “98% of airborne particles”. They don’t specify the size of the particles removed (or a range of sizes) either.

This may be due to the fact that there could be a slight difference between the HEPA-measured efficiency of the filter alone, and when the filter actually works to remove pollutants from a certain room area.

Still, Alen A350‘s appear to offer top-quality service for their customers.

Many online retailers and users speak highly of this model’s particle-removing capability.

Gaseous Pollutants

Alen A375 UV light air purifier has been specifically designed to fight gaseous pollutants which are commonly found indoors.

This type of pollutants are very harmful to human health because they are tiny in size and can enter the blood stream directly. They range roughly between 0.0003 to 0.005 microns in diameter.

Because of their size, it is also difficult to remove gases & odors from air with mechanical methods (such as HEPA filters).

Alen A375‘s ultraviolet plus photocatalytic technology in conjunction with activated carbon are the main techniques employed to eliminate gases & odors.

Gases & Odors

Gases & odors commonly present in an average home are much smaller than particulate pollutants.

That may be why gaseous pollutants are much harder to catch with mechanical filtration such as HEPA, than airborne particles.

Alen A350 purifier does not offer serious levels of removal of gases & odors as such.

That said, the same standard HEPA filter which is used inside Alen A350s to catch particles (called HEPA Plus) is also covered with a small amount of activated carbon to deliver general “odor control”.

We discuss different types of Alen A350‘s filter cartridges further down in this article.

If you have a medical condition and want to have a better control of gases & odors in your house, you should probably go for Alen’s other filter cartridges (compatible with Alen A350 air purifiers) with more powerful gas-removing capabilities.

Or choose another purifier brand altogether, ex. IQAir HealthPro Plus.

More On Technology

Alen A350 air purifier uses the standard HEPA Plus (BF25A) filter inside its unit, by default.

Below we discuss different technologies utilized by this filter to remove pollutants from domestic air.

HEPA technology

The main technology is, of course, HEPA.

HEPA stands for High Efficiency Particulate Arresting.

High-performance HEPA filters are usually made of fine glass fibers which are folded into pleats for larger surface area. They remove air pollutants physically, by working like a sieve and trapping particles inside their fibers.

HEPA filters catch at least 99.97% of particles 0.3 microns in size and larger.

This is exactly how the HEPA Plus filter works as well.

Activated Carbon

Activated carbon is widely used by many brands of air purifiers to eliminate tiny gases & odors from indoor air. And it works differently from HEPA technology.

Activated carbon attracts gaseous pollutants and adsorbs them onto its surface.

It is very effective at getting gases attached to its surface.

HEPA is inefficient at removing such tiny pollutants because HEPA is as good as the smallest hole in its fibers. It is unable to “attract” pollutants the way activated carbon can.

So a small amount of activated carbon is used by the HEPA Plus.

It does not deliver a thorough removal of gases & odors but is rather offered for general “odor control” purposes.

See below for more details on other types of Alen filter cartridges which do use more activated carbon and other compounds, for better elimination of gaseous pollutants.

Washable Pre-Filter

The HEPA Plus filter contains a pre-filter which catches larger-sized pollutants before the HEPA layer kicks in.

The big advantage here is that you can wash this pre-filter when you see a lot of dust collected on it.

But be careful not to wash the HEPA filter itself though, since it will damage the fibers.

UV Light Technology

Alen T300 utilizes UV light to fight against some biological pollutants such as bacteria, viruses and molds.

UV light works by altering the DNA of bacteria & viruses so that they can no longer reproduce effectively. In other words, UV deactivates them but doesn’t destroy them completely.

The UV’s success rate depends mostly on two factors: 1) intensity of UV light (i.e. the dose of UV radiation dispensed), and 2) exposure time (i.e. the length of time that air pollutants are exposed to UV radiation for).

We can’t appreciate the usefulness of this air purifier’s UV technology since the manufacturer doesn’t provide any test results for how efficient it is at removing biological pollutants.

However, you can see UV test results for Alen’s other model – Alen A375UV – here. Perhaps, it can give us some clues about Alen T300‘s UV efficiency as well.

There are concerns that UV light radiation can be harmful to human health.

UV systems can also produce ozone which is a lung irritant. It is not totally clear whether Alen T300‘s UV system is free of ozone emissions.

UV Light Air Purifier Safety Issues

There are concerns that UV light radiation can be harmful to human health.

The manufacturer states that UV bulbs are located deep inside the unit, and there is no danger of human exposure to this radiation.

UV systems can also produce ozone which is a lung irritant. It is not totally clear whether Alen A375‘s UV system is free of ozone emissions.

UV bulbs contain mercury which is also a toxic chemical. Take good care not to break the bulbs when changing them.

Photocatalytic Air Purifier Technology

Photo-catalytic oxidation (PCO) aims to destroy tiny gaseous pollutants by converting them into harmless substances.

Here is how PCO works:

  • A UV lamp irradiates a photocatalyst (usually titanium dioxide) with strong UV light
  • This creates a photochemical reaction and produces hydroxyl radicals
  • Hydroxyl radicals oxidize gaseous pollutants which have been absorbed on the catalyst surface
  • This process transforms organic pollutants into carbon dioxide and water (now totally harmless)

Alen A350 Air Purifier ReviewThis is exactly how the Alen A375 UV light air purifier works as well.

This machine uses a titanium dioxide filter as a photocatalyst. The filter is permanent and doesn’t need to be replaced.

PCO is a new, but quite promising technology.

From its description above, it appears to be able to potentially eliminate all (or at least most) gases & odors. Which is powerful indeed.

Alen Corp refers us to the test results of Alen A375‘s PCO technology.

After 4 hours of running this PCO-enabled purifier, the concentration of volatile organic compounds (VOCs) made of up formaldehyde, xylene and benzene in a room went down from 14 to 3.

We assume it was not an independent, but an in-house test performed by the company itself.

Other Types of Filters for Alen A350 Air Purifier

BF25A-MP: Gas/Smoke/Odor Filter

This filter appears to offer an advanced level of protection against gases, odors, smoke & other similar air pollutants.

Apart from the “signature” HEPA filter and a layer of activated carbon, it also contains “exclusive concentrated powder [which] uses a patented molecular conversion process to change smoke and most cooking & bathroom odors on contact“.

It is difficult to judge the effectiveness of this technology.

The company obviously doesn’t want to disclose specific components of this powder for us to have a better idea of how it works. And this is quite understandable.

This filter also has a pre-filter which you can clean, but be sure not to clean the HEPA filter itself.

GAS-MP: Smoke/Odor/Gas Filter

The manufacturer refers to this filter as their “specialty filter for maximum odor removal“.

It contains “twice the amount” of activated carbon found in their other filters.

It also contains “500 grams of our patented molecular conversion odor powder will change smoke and most bathroom odors to be odorless on contact“.

It does not include HEPA media, which is supposed to extend the life of this odor filter to 1 to 2 years.

BF25A-Silver: Virus HEPA Plus Filter

Virus HEPA Plus filter is very similar to the standard HEPA Plus (BF25A) one.

It is a true HEPA filter which also contains a layer of activated carbon and has a washable pre-filter.

The main difference is that, unlike the standard HEPA Plus filter, the Virus HEPA Plus has a silver coating around its HEPA layer.

Silver is a well-known and time-tested natural anti-biotic.

It is used by many good air purifiers.

Here is how Alen Corp explains silver’s work in its purifiers:

It is a definite plus to have silver in one’s home air cleaner.

Room coverage

According to Alen Corp, the Alen A375 UV light air purifier can cover a room area of up to 800 sq. feet. If you use it for a room this size, you’ll roughly have two full air changes an hour.

However, for “best performance” the company recommends an area of 400 sq. feet. This will give you four full air changes an hour.

Some online allergy-specialty retailers recommend a room size of 286 sq. feet for this machine. This will deliver six full air changes an hour.

The more full air changes an hour your air purifier can achieve, the better.

Optional Built-In Ionizer

Alen A350 air purifier has a built-in ionizer which can be manually turned on and off.

The ionizer generates negatives ions which have been widely recognized to have beneficial effects on human health.

Negative ionization improves the quality of air and has been even shown to help with experimental treatment of such conditions as depression.

So having an option of using this technology with Alen air purifiers is undoubtedly a huge benefit to their users.

Alen Corp re-assures us that all their air purifiers are ozone-free.

They refer to independent tests performed on their other model – Alen A375UV air purifier (presumably using the same ionization technology as Alen A350s) – to prove this point.

These tests found that:

The Alen A375UV Air Purifier averaged 0.004 ppm which is 92% below the FDA limit [0.05 ppm] and slightly less than the ozone measured in the room before the unit was turned on. Based upon these results the air purifier is considered ozone safe.

We take their word for it.

Ozone is generated as a by-product of air ionization, and is a lung irritant.

That is why it is important to make sure that an ionizer you are looking to buy is completely ozone-safe.

There are many cheap ionizers on the market that not only fail to effectively clean the air of pollutants but also produce high levels of ozone which are damaging to human health.

Be sure to avoid such “air purifier” brands.

Design & Construction Quality

Alen A350 Air Design SkinIt’s not immediately clear how the air travels through the Alen A350 air purifier – no specific details on it on the manufacturer’s site.

Our best guess (by looking at the pictures taken from different angles) is:

  • Air enters the unit from the inlets at the unit’s front
  • Air then passes through the filter in the center of the unit, and
  • Air exits the unit from the top outlet at the unit’s back

This design differs significantly from some other prominent brands such as IQAir air purifiers and Blueair air purifiers.

At the same time, it looks well thought through and appears to prevent so-called shortcutting which is common in other mass-produced purifier brands.

Shortcutting becomes possible when an air intake and an air outlet are located close to each other. This allows newly filtered air to get re-drawn into the unit and go through the filtering process again.

This, of course, is a waste of the unit’s cleaning capacity which should be used for purifying polluted air from the room.

Filter Changes

Alen A350 Air Purifier ReviewAs we mentioned above, the Alen A350 air purifier uses an all-in-one filter at any one time – be it a BF25A-Silver, BF25A-MP or any other one.

This means that when the time to replace the filter comes round, it has to be done all at the same time.

You can’t change a pre-filter, a HEPA filter, an activated carbon layer or even a silver coating separately from each other, but all at the same time.

This may be a waste of resources because home environments are different from each other.

Some homes may have more larger particles in them (more of a HEPA filter will be used and other filters’ capacity will be saved) while others will have more odors to deal with (more of an odor filter will be used and other filters’ capacity will be saved).

But of course there is a clear user convenience in it – less hassle when all is done in one go.

Digital User Controls

Alen A350 air purifier has an intuitive LCD display with electronic push-button controls, at the very top of the unit.

This model offers 4 fan speeds which you can set using the relevant button on the unit’s display.

A 12-hour timer allows you to set your unit to run for a certain period of time – it will shut off automatically once the set time has run out.

A filter-replacement indicator will let you know when to change your filter.

You can also turn your ionizer on and off using one of the display buttons.

This model does not offer a remote control.

And it does not feature auto-sensors to measure pollutant levels in your air.

Construction Quality

Alen A350‘s housing is made of plastic.

Some online reviewers mention high construction quality of all Alen air purifiers.

Although we can’t judge this issue from our direct experience, experts point out their tight design, meaning “case, gaskets, seals, and precision fitting eliminate bypassing and assure high efficiency at filtering sub-micron particles“.

Other Functionality

Filter’s Lifespan

The average filter life (we assume this holds for all Alen’s filters) is 69 months.

It appears to be short compared to some other premium air purifiers.

Ex., IQAir‘s HyperHEPA filter’s life is 2 – 4 years. But then again IQAirs are a lot more expensive.

But Alen’s filters have the same lifespan as more expensive Blueairs.

Alen’s filters appear to be reasonably priced.

Reasonable Noise Levels

Noise produced by an air purifier is a very important issue, especially if you are planning to use it in your bedroom.

It is obviously a challenge for manufacturers to find the right balance between the noise produced by a fan’s operation and the volume of clean air delivered as quickly as possible.

When doing your research, remember to judge noise levels of an air cleaner by the actual volumes of clean air it produces at a certain noise level. Such clean air volumes are usually measured in cubic feet per minute (cfm).

Alen A350 air purifier offers 4 fan speeds.

For each of its speeds, this model delivers the following volumes of clean air and noise levels (measured in decibels):

  • Speed 1: 40 cfm @ 36 dB(A)
  • Speed 2: 85 cfm @ unknown dB(A)
  • Speed 3: 160 cfm @ unknown dB(A)
  • Speed 4: 225 cfm @ 65 dB(A)

Some users complain of it being noisy on higher speeds.

It is recommended that you use it on higher speeds if you need to clean your air as quickly as possible, and then switch to lower speeds.

Lower speeds are obviously recommended for night-time as well.

Room Coverage

According to Alen Corp, an Alen A350 can cover a room area of up to 800 sq. feet.

If you use it for a room this size, you’ll roughly have two full air changes an hour.

However, for “optimal performance” the company recommends an area of 400 sq. feet. This will give you four full air changes an hour.

Some online allergy-specialty retailers recommend a room size of 281 sq. feet for this machine. This will deliver six full air changes an hour.

The more full air changes an hour your air purifier can achieve, the better.

CADR Rating

CADR Rating For PurifiersLike many manufacturers of other quality air purifiers, Alen Corp originally decided against getting a CADR rating for their purifier models as well.

We discuss the flaws of CADR rating system in more detail here.

But it appears that they did go for it eventually, in order to get an Energy Star certification (see below) for their Alen A350 air purifier.

So, Alen A350‘s CADR ratings are as follows:

  • Dust: 217
  • Tobacco Smoke : 201
  • Pollen: 216

Energy Use

Alen A350 air purifier is a highly energy-efficient machine.

Here is how much energy it uses (in Watt / hour) on each of its speeds:

  • Speed 1: 55 Watt
  • Speed 2: 65.5 Watt
  • Speed 3: 73 Watt
  • Speed 4: 90 Watt

Alen A350‘s energy consumption is similar to that of energy-efficient Blueair air purifiers, and beats IQAir purifiers hands down.

Alen Corp has also received an Energy Star certification for their Alen A350 model.

Here is how Energy Star describes room air cleaners which receive their certification:

  • [Certified room air cleaners] are 40% more energy-efficient than standard models saving consumers about 340 kWh/year and $35 annually on utility bills. These savings could add up to more than $330 over the life of the air cleaner
  • [Certified room air cleaners] that offer secondary features such as clocks and remote controls consume less than 2 watts while in standby mode

The Energy Star specification for room air cleaners measures energy efficiency by using a CADR/Watt ratio.

Warranty Period

Alen Corp caused a stir in the market when they introduced their Lifetime Warranty program for all their air purifiers including the Alen A350 air purifier.

That is how they explain it further:

We are the first and only air purifier manufacturer to offer a lifetime warranty. We’re that confident in our quality and want none of our air purifiers to ever end up in a landfill. Our commitment to our environment goes beyond our lifetime warranty, all of our air purifiers are ozone safe.

We warrant your Alen Air Purifier to be free from defects in material or workmanship for as long as you own it.

But to activate this lifetime program for your unit, you need to subscribe to their replacement filter plan.

This plan requires that you buy new replacement filters every 6 months for your machine.

Of course, any lifetime warranty program (without major catches) is admirable.

The main question is: if Alen Corp warrants your Alen purifier to be free from defects in materials and workmanship, what about normal wear & tear?

Is there a rough timescale after which your Alen unit can potentially fail due to wear & tear? How is that going to keep it from breaking down? (Obviously, once your unit is done, please try to recycle it instead of dumping it in a landfill).

Or are they going to keep replacing the parts until your unit is almost new again? (That, too, would be admirable). Perhaps, your 6-monthly filter-subscription would cover these costs as well?

There is nothing in this life that lasts forever, especially a man-made product.

It would be good if the company were a bit clearer on this point.

Environmental Issues

Once again, we admire that the company tries to keep their units in operation for as long as possible.

We know that the housing of Alen air purifiers is made of plastic.

Plastic is not the most environmentally-friendly material but that is the reality of life at the moment. Most air purifiers use it.

But at least it would be good to know if Alen’s plastic (and other components) can be recycled at the end of their useful lives.

Who Should Consider Getting An Alen A350 Air Purifier

Alen A350 air purifier is one of the most reasonably priced models on the market with a decent particle-removing capacity.

So if you are on a tight budget, this is a good choice.

At the same time, if you have serious allergies or other pollution-related conditions you may want to try using Alen’s other filter cartridges with more powerful odor-removing capabilities (we discuss them above) and not just Alen A350‘s default Virus HEPA Plus filter.

Or go for Alen’s other model – Alen A375UV.