The Ultimate HEPA Air Purifier Guide

Today there is such a variety of air purifiers on the market that it has become very difficult to know which HEPA air purifier will best suite your needs. Each company puts efforts into marketing their specific models, often using catchy buzzwords and confusing tech terms that do little to explain what the purifier can really do for you. Don’t worry, we are here to help!

hepa air purifier

HEPA Air Purifier Reviews

We make it a point to provide you with detailed and highly informative HEPA air purifier reviews that provide you with the important information you need before making a purchase… and then some! While doing our best to stay unbiased, we definitely have our favorites and sometimes it shows.

But that is just because we are passionate about HEPA air purifiers and their ability to help people and improve the quality of life. By taking information from a variety of sources that are sometimes hard to track down, we strive to present only the most accurate and helpful information to you. While most of our air purifier reviews are to-the-point and a quick and easy read, some of our favorite models have received a bit more attention with the reviews presenting a wealth of information.

When most people start out looking for the best air purifier, they have very little knowledge about the products themselves. What they do tend to have is a problem of some sort that needs fixing. Different purifiers offer a variety of filtration methods and some are better suited for some air quality issues than others. Maybe you have typical seasonal allergies? Perhaps you have a pet that your daughter is allergic to? Maybe someone in your family has MCS (Multiple Chemical Sensitivity) or even still perhaps there is a smoker in the house and odor is the issue.

Whatever your situation is, it is very likely that there is a HEPA air purifier out there designed to address it. The tricky part is sifting through the garbage and learning exactly what you need. Plan on reading through a handful of air purifier reviews so that you can begin to understand what various models offer and how different companies and price-points vary with what is offered. This does not take long and the due diligence on your part is worth the time. Below I will outline some steps to take to get started the most efficient way possible.

Steps For Picking Out The Perfect HEPA Air Purifier

Decide what air quality issue you are trying to tackle: What kind of allergies do you have? Are you trying to address airborne chemicals? Are odors the issue?
Identify the size of the area you are hoping to purifier: It is important that the purifier you decide on is capable of maintaining the air quality in the room or rooms that you bought it for.
Know your budget: As you will see, HEPA air purifiers range from under $100 to well over $1000. There is a lot of good stuff out there these days and getting a solid HEPA air purifier doesn’t have to break the bank. As you browse you may realize many models seem above the budget you originally had in mind. I would say that by splurging just that little bit extra up front increases your chances of having a quality product that will meet your needs for years to come.
Understand the costs of operation: Some purifiers have a long filter life while others will have a short one. Many have carbon pre-filters that need replacing. Some are more energy efficient than others.
Bells and Whistles: There are air purifiers with UV germicidal lamps, humidifiers, ionizers, sleep modes, pollen modes, remotes and even artwork on them. If some of these features would make you happy, explore what is offered before you make a final decision on the best air purifier for your home. By keeping the pointers above in mind, you will already be way ahead of the game.

hepa air filter

The Creation of the HEPA Air Filter and Why They Beat The Rest

HEPA air filters were first developed in the 1940’s by the U.S. Atomic Energy Commission. The initial purpose of the technology was to filter radioactive contaminants from the air during the initial research and development of the atomic bomb. The technology soon went public and many industries began using these highly efficient filters to meet greater demands in air quality.

HEPA air filters are regulated by the U.S. Department of Energy to meet strict guidelines regarding their ability to filter airborne contaminants. To meet the classification of HEPA air filter, it must be able to capture a minimum of 99.97% of airborne particles .3 micrometers in diameter. To put that into perspective, .3 micrometers is about 1/100th the width of a human hair. The particles being trapped are generally 25-50 times smaller than what the eye can see. Some HEPA air filters are able to capture, even more, reaching 99.975% percent efficiency! The ability of these filters and the purifiers containing them goes above and beyond what almost all non-HEPA purifiers can do.

These factors are important when it comes to the contaminants we are up against. A HEPA air filter can be a great tool for someone with allergies. Pet dander, pollen, mold spores, dust, and smoke can all wreak havoc on a susceptible person’s immune system. All of these allergens are very small in size and this is where HEPA filters really prove their worth. Assuming that the HEPA purifier you purchase is sufficient to filter the volume of air in your home, you will undoubtedly notice the comforting benefits of breathing the fresh air that it provides.

The Importance of Reducing Air Contamination Sources

If you have made it to this website, it is very likely that you either have a health issue you are hoping to improve or are otherwise hoping to take preventative measures against potential threats to your future health. It often seems that those seeking out air purifiers as an option are expecting and instant and complete solution to their problems without committing to any other environmental or lifestyle changes.

What is important to understand is that whether it is household odors, chemical off-gassing from household materials, pollen, mold, or dander allergies that are causing your problems, there is a source feeding your home with these contaminants. Now I do realize that in many cases, it is extremely difficult to eliminate these sources. However, an attempt must be made because even though some of the today’s best air purifiers are amazing, they are not always a fix-all solution. Let’s take a look at the situation of a household that has a pet to which they are very attached. Getting rid of the pet is not an option, and someone in the household has allergies to the proteins in the animal’s dander and saliva.

Now obviously in this situation, anything short of getting rid of the animal will not eliminate the allergen source. Keeping the animal outside, on the porch or in the garage for some of the time can directly help reduce the source of allergens. Additionally, restricting where they are allowed to go in the house is smart. Considering most people spend a large portion of their day in their bedroom, it makes sense to keep this as an allergy-safe haven. Minimal dander will be in the room if you keep the door closed and make sure the animals know this area is out of bounds. Even still, allergens will remain and persist in the home. I think it is important to utilize some other tools and products that you could incorporate into a broader system, which includes air purification, to address the issues.

For example, replacing your homes standard furnace/AC filters with MERV rated models can help grab what the air purifier may be missing and seems like an obvious choice for those wanting to be proactive about the situation. The higher the MERV rating, the better the efficiency at trapping smaller particles. Check with someone at a local store about compatibility and adverse effects with your particular unit.

Another great tool to incorporate is a true HEPA vacuum cleaner. While they can be a bit pricey, if you can afford it these seem like another obvious choice. settled allergens regularly get kicked up from surfaces like carpeting and furniture and are reintroduced into the air where they are easily inhaled and allowed to make contact with your eyes. You should think of settled dander as a “source” just like the animal itself is.

The same way a HEPA air filter on an air purifier can trap small allergy-inducing particles in the air, a quality HEPA vacuum can grab all the stuff that has settled and assure that it is not redistributed into the air. On top of this, I would hope that if you (or someone else in the household) knowingly suffer from pet allergies, that you clean surfaces in the home regularly. At least a couple times a week I would recommend vacuuming off the furniture and wiping down other surfaces where dust would normally gather.

I would also look into shampoos and sprays that you can use on your pets to help reduce dander and break down the allergy-causing proteins in their dander and saliva. Seeing as how dogs and cats seem to always be licking their fur, they become coated in dried saliva.

This is why simply petting the surface of their coat can induce allergy symptoms. As much as you love your animals, it is essential to limit exposure. It is still possible to share affection with your animals while at the same time minimizing h0w often you actually make contact with them. When you do choose to pet them, thoroughly wash your hands with soap and water immediately. You may also want to look into some natural allergy remedies and antihistamines.

Other examples might include removing your shoes at the front door to avoid tracking pollen into the house or keeping windows closed during allergy season. Another would be to find and remove mold in your home instead of expecting an air purifier to just take care of all the mold spores floating around. They are coming from the mold which needs to be taken care of first. Residual spores and those naturally occurring in the environment can be taken care of by an air purifier but a large infestation of growing mold in your home can not.

These same principles can apply to other allergen sources as well. Again, while HEPA air purifiers can do a great deal to improve the air quality conditions in your home, it is important to keep in mind that reducing the source of those allergens is important as well thus giving the purifier a “fair fight” against poor air quality.

true hepa filter

Why A HEPA Air Purifier Is Important In The Winter

While most of us tend to think of the spring as peak allergy season, there are still many year-round air quality concerns in our homes. As we approach the winter months, there are several factors which may negatively affect the air in our homes even more than in the warmer months. For starters, it is known that the air outside is generally much better than the air in our homes. A main contributing factor to this is that there is minimal circulation inside our homes and seldom do we flush our homes with fresh outside air. This is true during the colder months of the year, making winter allergies worse.

In order for our homes to stay well heated during the winter, it is crucial that they are sealed well, minimizing any possible areas where the heat may leak out. This fact means all the contaminants in our homes are trapped inside, being recirculated and built up over time. To add to the problem, both people and their pets spend significantly more time indoors when it is cold outside. This exposes us to the toxins and allergens in our home for more time, pushing our bodies and immune systems harder and harder to keep up with the onslaught.

A few other factors that may add to poorer indoor air quality during winter months are the use of furnaces and fireplaces and increased duration and use of gas stoves and burners. We tend to eat more hot foods and more of the types of foods that typically require extensive cooking (ie- soups, roasts, casseroles, etc). These activities contribute combustion particulates and gases to the air in your home which has been proven to be harmful to humans.

Additionally, I’m sure we have all noticed that cool air is drier air and often dries out both human and pet skin. Because the main ingredient in dust is dead skin cells, this time of year might leave your house collecting much more dead skin than in the warmer months.

So as you can see, while we often forget about the need for a HEPA air purifier in non-“allergy” seasons, it remains an important consideration for your home. I would suggest browsing for purifiers in your price range and getting a Christmas present for the whole family. A good place to start would be the Honeywell 50250, one of the best selling air purifiers on the market.

“True” HEPA Air Filter Vs. All The Rest

With so many air purifying products on the market, it is very easy for companies to make claims and use certain wording or phrasing to confuse the consumer and lead them to believe things about their product that are not necessarily true. We will cover all of these marketing practices in the future, but today we are going to talk about what it means for a product to be considered “True HEPA” and what it means for a product to be labeled “HEPA-like.”

To consumers, the acronym “HEPA” is synonymous with quality, and for good reason. A HEPA air filter is the best at purifying the air of the small contaminants that cause humans the most trouble. To be a “True HEPA” filter, specific testing demonstrating its ability to clean particles from the air must be performed. This certification allows the filter to be advertised and sold as a “HEPA” air filter, and they work very well.

best air purifiers

HEPA Type or HEPA Like VS. True HEPA

Now comes the marketing confusion. Many companies have products, be it an air purifier, a vacuum, or a replacement filter which they label as “HEPA-like” or “HEPA type.” While this rings well in the consumer’s ear, they are being misguided. If in fact, you are not looking for a highly efficient and effective way to clean your air, then these filters may work. But I would assume most of us purchasing these types of products are either already suffering from adverse health symptoms or are taking a precautionary measure and are concerned for the well-being of ourselves and our families.

These filters are typically much worse at trapping the small particles that are hurting us. They share a similar design to real HEPA filters but do not meet the strict standards of their certified counterpart. I would strongly advise that for the few extra dollars, you go ahead and make the investment in a product that is proven to make a positive impact on your air quality. To be labeled a true HEPA air filter, it must be capable of trapping a minimum of 99.97% of particles .3 microns in size and larger that pass through the filter.

I have seen many HEPA-type filters claim to trap “over 90% of particles 2 microns and larger” or similar amounts. The problem is many of the airborne particles inducing your allergy symptoms are smaller than 2 microns and not only this, these filters are less efficient (90 some odd percent vs 99.97% plus) than a true HEPA filter. As you shop around, you will see some purifiers that utilize HEPA filters that are even better than the standard.

Some are capable of trapping particles at 99.97% efficiency and some can trap particles down to .1 microns or even .003 microns! So again, it really depends on what you need. If it is odors that are the problem, you probably don’t need a true HEPA filter. If you want to reduce settled dust on the coffee table, you could probably get by without it. But if allergies are the issue, there really is no other way to go.

Is A HEPA Air Filter A Good Weapon Against Mold?

Although mold is an everyday word, we rarely think of it as what it is – a microscopic fungus. It just so happens that many types of mold grow very well in places that are dark, warm, and damp. When certain types of mold begin growing in a home, those tenants who are allergy prone will often develop adverse reactions. Now contrary to popular belief, it is not the actual mold that is responsible for the allergic reaction, but rather the mold spores.

These spores are the mold’s means of reproducing and are essentially tiny seeds that get in our airways and agitate our immune systems. I would recommend anyone suffering from allergy symptoms and is having difficulty tracking down the source, to get their house tested for mold. Symptoms can include sneezing, watery/itchy eyes, sinus problems, breathing difficulty, headaches, cough, runny/stuffy nose, and rashes.

hepa air filters

Air Purifiers and Mold
Luckily, there is a very effective tool to fight back against these mold spores and thus reduce or eradicate your allergy symptoms – the HEPA air filter. Because mold spores range in size from about 1-5 microns and HEPA air filters can trap almost 100% of particles .3 microns and bigger, they are the perfect tool for the job. The purifiers should be placed strategically, in places where mold is growing and reproducing (ie-bathrooms, basements, etc). By using an air purifier to stop the mold from reproducing in combination with dehumidifiers to make the environment inhospitable to the mold and a true HEPA vacuum cleaner to clean spores trapped in carpets and upholstery, it is possible to take back your home from mold and thus free yourself from your mold allergy symptoms.

Pet Allergies and the Use of a HEPA Air Purifier

The practice of humans keeping animals as pets has been around for many thousands of years. Not only do they provide companionship, affection and unconditional love, they also provide health benefits through their ability to nourish our mental health and encourage us to be physically active (ie-walking your dog). Many millions of these pets achieve a “family member” status, reaping rewards and treatment far surpassing what any pre-civilization animal could ever have imagined. For most families, the thought of parting with their beloved pet is unconscionable.

According to the American Pet Products Manufacturers Association (APPMA), there are 73 million dogs and 90 million cats kept as pets in the U.S. alone and the pet ownership numbers are trending upwards. One of the many problems that come along with this level of pet ownership is the allergies associated with proteins in the animal’s dead skin cell’s (dander), saliva, and urine. An estimated 15-30% of people with allergies have allergic reactions towards cats and dogs with cat allergies being twice as common.

The Best Air Purifier for Pet Dander

The dander which is continually released into the home by these animals should be of the most concern to the allergy-prone individuals. These small particles of dead skin can easily permeate the home environment, settling on all surfaces of the home and suspending in the air. Using a HEPA air purifier is a very effective way to filter these allergens from the air inside your home. While dander particles are several microns big, a true HEPA filter is capable of trapping particles down to .3 microns in size. So really, it is more effective/efficient than you need but by looking out for the true HEPA labeling, you are guaranteeing the filter is capable of collecting at least 99.97% of these dander particles.

It takes the guess work out of looking for a purifier for your needs. Ideally, the HEPA filter would be of the “whole house HEPA air purifier” variety indicating that it is capable of cleaning the large volume of air that occupies an entire house. Many portable “room” air purifiers max out at several hundred square feet. There are a few options from IQAir and Austin Air that can get into the 1000 sq. foot range and higher which may be the way to go if your allergies are severe and you have several animals. Alternatively, smaller units are available which may be effective in controlling dander in a more confined area (ie-your bedroom). Combining air purification with the use of a HEPA filter equipped vacuum and a regular and diligent home cleaning schedule, it is possible to control dander allergies. I would also recommend a HEPA vacuum to take care of settled dander.

Best Air Purifiers Around $100

While consumer electronics are getting better generally getting better in quality and affordability, you have to be careful when considering air purifiers under $100. For starters, many of these cheaper purifiers are designed to clean rather small spaces. As you may already know, this is crucial when it comes to addressing air quality issues. The unit you use should be powerful enough to clean the area you are considering.

Secondly, many of the air purifiers on the market that are under $100 consist of the electrostatic/ionic variety and those that aren’t are still often not true HEPA filter equipped. Those are my two biggest concerns with this price range. The other things you are passing up tend to be conveniences like various modes, speeds, carbon filtration, remotes, timers and what have you. The best air purifiers under $100 should utilize a true HEPA filter and be capable of cleaning the space you require. Do not buy a purifier rated to clean 60 sq. feet if you want your entire home purified.

Check out the best air purifier under $100 on Amazon.

Best Air Purifiers under $250

Purifiers in this price range start to offer more features and more importantly are capable of moving more air and thus cleaning larger spaces. Even those who suffer from significant allergies should be able to find relief using one of the best air purifiers under $250.

Check out the best air purifier under $250 on Amazon.

Best Air Purifiers under $750

Getting into this price range can really begin to open up the possibilities for you to find real relief. Typically the best air purifiers in this price range can clean larger volumes of air which is important to their effectiveness. They may also offer a better build quality and may potentially offer more in terms of extra features. In terms of home air purifiers, this price range gets into some of the best of the best. It’s hard to find a truly bad unit in this price range, but we have our favorites.

Check out the best air purifier over $250 on Amazon.

best air purifiers

Best Air Purifiers for Smoke

Because tobacco smoke particles range from .01-4 microns in size, it is critical that you get a purifier that utilizes a filter capable of trapping particles of this size. The best air purifiers for smoke will have a filter capable of trapping particles down to .01 microns with good efficiency and will contain additional filters designed to address the gaseous components of tobacco smoke which contribute to the odor and are toxic. The best solution for this is a large quantity of high grade activated carbon.

This is one area where many companies skimp and if you want true effectiveness with odor and gaseous toxin removal, there must be enough carbon to absorb it all. While not many purifiers can trap particles .01 microns big, you will ideally want a HEPA filter that is capable of trapping particles smaller than .3 microns a HEPA filter is typically capable of. The following purifiers are our picks for the best air purifiers for smoke and are designed for different square footage’s and are offered at varying price points.You can browse other offerings by the same brands to potentially find a better square footage/price match for your needs.

Best Air Purifiers For Odors

Odors are the results of gaseous compounds floating around in the air and getting inhaled. There are plenty of causes of offensive household odors and they do not differ all that much. Whether it is pets, cooking, smoke or any other cause, the best air purifiers for odors will have a good amount of high quality activated carbon inside. Additionally, an ionizer or ozone emitter of some sort can help to neutralize many of these gases rendering them harmless.

Indoor air pollution? A Shocking Truth

If you were to ask most people where they thought they would be most likely to experience air pollution, they might mention traffic fumes, smog looming low over large urban environments, smoke billowing from a factory chimney, or their local volcano.

However, most would not consider the quality of air inside their home as being a major source of pollution. This is unfortunate, as indoor air pollution has become a growing concern in recent times – and for good reason: The United States Environmental Protection Agency has stated explicitly that indoor air pollution is one of the top five risks to the health of the public!

Studies have shown that people in industrialized nations very often spend more than 90% of their time indoors – and unbeknown to most, many air pollutants often exist indoors in greater concentrations than outdoors. In some cases, this is fairly obvious – such as tobacco smoke, exposure to which is obviously much greater indoors. However, there are many other pollutants – such as styrene, formaldehyde, dust, asbestos, carbon monoxide, and even lead that may exist in indoor environments.

All in all, there are a huge array of possible pollutants that could exist in the indoor air. Here in, we’ve investigated and researched into many of these pollutants – and written up a series of articles which you can read.

Also, in the quest for energy savings, the efficiency of modern home insulation has been greatly increased – such as with the use of draft excluders and other methods of draft prevention such as double glazing. However, although these methods might work brilliantly for reducing heating or air conditioning bills, the fact that modern homes are more “sealed” than those of old times, might very often mean that many homes may have less air circulation than they once did – with the result that air pollutants are more likely to remain trapped indoors for longer periods of time.

The good news, however, is that you can take action – and there is a lot you can do! From regulation of ventilation, the use of air purifiers, selection of construction materials and careful use of appliances i.e. stoves – there are many simple ways to reduce indoor air pollution. There are many different air purifiers on the market today – and these can often use a bewildering array of possible technologies. We’ve looked into some of the major brands and the various technologies that are available and do what we can to unravel the mysteries of these amazing machines!

filter capable trapping

Common indoor air pollutants


What is “house dust” / indoor dust made of?
“It’s just dust, isn’t it?” Indoor dust may not look as though it is made of anything very spectacular – and this is probably in some ways a good thing – because if most people knew what some of the ingredients were, they may well be horrified and become obsessed with getting rid of it!

Indoor dust is composed of an incredible cocktail of ingredients – and its composition obviously varies depending on the contents of the indoor environment in question. Common house dust ingredients can include: Dead skin cells (human and animal), dust mites, dust mite excretions, mold / fungus spores, pollen, dead insect parts, wood dust, paper dust, dried urine, particles of metal, paint, plastic, hair, wool, soil, rock dust, soot, food waste… and chemical dust from the thousands of industrial products in our modern world.

The smaller these particles, the easier it is for them to become airborne. The greatest constituent of dust in indoor human environments is usually dead skin cells – mostly of humans but also from pets. Although you may not have a visible dandruff problem, skin cells are dying and falling off your body all the time! It happens to all of us and is an essential part of having healthy skin. Dust found in homes also contains atmospheric dust – minute particles blown in from outdoors. Atmospheric dust can contain soil particles, pollution, and particles from volcanic eruptions – and might possibly even contain small amounts of dust from outer space i.e. from comets.

The vast majority of particles in the air is in the “ultrafine” range – that is to say, smaller than 0.1 of a micron or one ten-thousandth of a millimeter in size. Indoor dust is a known problem for hay fever and other allergy sufferers.

Exacerbation in recent times
Although the dust has been around since time immemorial, in some ways the problem of domestic dust may have become worse in recent times, due to diverse factors.

One such factor, ironically, is the draft-proofing of homes. Although this might help keep your heating or air conditioning bill down, the lack of ventilation also keeps dust and other airborne pollutants such as chemical sprays and VOCs within the home.

Another factor increasing the problem caused by dust is the increase in the number of manufactured products in our environment. Many of these create dust, which then adds to the “chemical soup” we are exposed to, and which may possibly cause serious health problems. See dust toxins page for more info.

So, what can we do about dust?
Well, first of all, don’t panic. Ok, so you may possibly be breathing tiny particles of dead insects and your cat’s dandruff, but remember that dust has been a part of our lives since humans began to live indoors!

In the reality of our everyday living environments, it is practically impossible to get rid of dust completely, because it is constantly being made – in countless different ways. However, there are several things we can do to reduce the amount of dust we breathe. We have compiled a few tips which may help.

Dust toxins

Toxic substances in dust
Dust toxins: Some commonly-used manufactured products are highly toxic, and although in recent years great efforts have been made to understand their effects and reduce the amount of these substances in our environment, many toxins are still sometimes found in our homes and offices – and can often create dust particles. Here are just a few examples of the many toxic substances that could possibly be found in dust.

Lead has long been known to be highly toxic. Great efforts have been made to phase out the general use of lead from several home construction applications where it was once commonplace. Much of the old lead has now been removed from homes – but some old plumbing pipes and old paintwork may still contain lead. When the old lead-based paint is sanded, burned, or rubbed, dust is produced. Also, dust is produced when paint deteriorates and cracks.

Much of the paint used on homes prior to 1960 contains lead, and some paint up to 1978 contains lead. Additional sources of lead might be traffic fumes, or soldering (many commercially available solders contain lead alloys). Although lead has been phased out of use as a gasoline additive, soil near to major roadways may contain lead and dust accumulated from years of traffic fumes – and this can be picked up and enter the home.

Although many asbestos products have now been banned, it can still be found in some homes e.g. in old furnace insulation or textured paint. Most problems occur when these materials are disturbed / improperly removed – as asbestos dust can be released – and the best thing to do is to have asbestos removed by a qualified professional.

Another example of chemicals which have been found in dust is polybrominated diphenyl ethers (PBDEs). PBDEs have been commonly used in fire retardants and may be found in electrical goods, carpets, and furniture. PBDEs are chemically similar to the notorious PCBs (which have been banned for their negative health effects) although the effects of PBDEs are not as well understood yet. Several types of PBDE have been banned in Europe and some have been banned in California as of January 1st, 2006.

It is interesting to note that IKEA phased out PBDE’s in 2002 and that many other companies have either limited or discontinued their use – such as Apple, Motorola, Sony, and Toshiba.

In summary, although it is often unclear how much of these toxic substances may be required to constitute a health hazard, and although of course opinions may vary, it could be said that avoiding breathing the stuff if possible, and breathing pure air, is probably a good idea!

activated carbon filters

Dust mites

Your carpet is alive…
Dust mites are microscopic creatures and are mostly found in the fabrics of carpets, bedding, and furniture although they are so tiny that they can become airborne. Dust mites eat tiny particles of organic matter – especially human skin cell dust. They also like to eat remains of other insects such as silverfish, fleas, and roaches. They are so small that they cannot be seen without a powerful magnifying glass or microscope. This might be a good thing because when looked at under a microscope they are pretty gross.

Dust mites are eight-legged and are related to spiders. And the shocking fact is that there may easily be tens or hundreds of thousands of them in your home! Laying eggs and excreting! The excretions of dust mites create…. you’ve guessed it… more small dust particles! These excreta can be harmful and are known to be major triggers of asthma and allergic reactions to dust. Dust mites do not bite or sting, but it is claimed that 10% of the population is allergic to their droppings – which are so small that they are easily stirred up and breathed in!
Most of the human allergic reactions to dust are caused by dust mites and their excreta.

Dust mites thrive in warm humid environments and studies in such climates have found as many as 18,000 per gram of dust. Chances are, they are living in your bed. Nice! A used mattress may have anywhere from 100,000 to 10,000,000 dust mites living inside it!

What can be done to get rid of dust mites?
Well, unless you want to live in a clean room wearing a spacesuit (which actually sounds quite appealing in some ways to us over here at HQ! ), you pretty much have to deal with the fact that there are going to be some dust mites in your life. Like I said earlier, it might be good that we can’t see them. But we can reduce their numbers.

The greatest factor in dust mite proliferation is humidity. Dust mites like over 50% humidity, and under 40% is optimal in controlling their numbers.

Dust mites’ prime habitat is bedding. Pillows and mattresses are most prone as these are not cleaned often. Allergy stores may carry covers for pillows and mattresses that are impermeable to the mites. Washing bedclothes in hot water (130 deg F) is commonly recommended although this is hot enough to scald and hotter than the water coming out of most hot taps! Fabrics that cannot be washed on a hot setting can apparently be put in the deep freeze for 24-48 hours to kill dust mites.

Another thing that may help finish off those pesky mites is to put pillows and fabrics through a tumble drier. Unfortunately, even after much Google searching we could not find reliable figures for what temperatures are reached inside a typical consumer tumble drier – but they seem to be in the range of 125 deg F (delicate setting) to 175 deg F – which combined with the low level of humidity, would appear to be a good idea for getting rid of mites – although we have found no actual scientific study on this subject.

Dust mites love your carpet. If you were serious you get rid of carpets in your home and replace fabric-covered furniture with leather or vinyl upholstery (but it would probably be easier to get a good HEPA air purifier).

Replace feather and down pillows with ones that are made of synthetic fibers/machine washable. Having carpets steam-cleaned is a good way to get rid of dust mites. Other effective measures include: vacuuming regularly, use a HEPA air purifier, and wash bedclothes and other fabrics regularly. Because of their air-cleaning effect, HEPA air filters might just help prevent you from breathing in these critters and their feces!

capable trapping particles


bonfires, cigarettes, traffic, burnt toast and more
Smoke is a by-product of combustion. Smoke might contain any number of an incredible array of ingredients. The chemical composition of smoke, and its degree of toxicity depends on many factors, such as the substance being burned, the temperature at which it is burning, and the availability of oxygen.

Many of the substances that can be found are toxic – and smoke inhalation is the commonest cause of death in indoor fires. Of course, some smokes are much more harmful than others – but even “ordinary” wood smoke, in use since ancient times, may be harmful. Some of the particles in smoke are visible to the eye, and some are not – and this depends largely on their particle size.

Depending on what is being burned, some examples of substances that might be found in smoke are soot (carbon), nitrogen oxides, hydrogen cyanide, polynuclear aromatic hydrocarbons (PAHs), thiols, formaldehyde, ketones, carboxylic acids, halocarbons, terpenes, carbon monoxide, phosgenes and methoxy phenols. Doesn’t sound much like a recipe you really want to ingest, does it?

PAHs – such as Benzo[a]pyrene, naphthalene, and pyrene are often found in wood smoke – and some PAHs are carcinogenic. Depending on what is being burned, particle sizes in smoke predominantly range between 0.05 microns and 0.5 microns – so an air purifier which is effective at removing smoke needs to be able effectively to remove particles in this size range from the air. ( a micron is 1/1000 of a millimeter )

However, combustion also produces gases – and an air purifier that has to deal with smoke not only needs to be able to trap very fine solid particles, but also gaseous substances. This is a reason why many air purifiers contain both HEPA and activated carbon filters.

Some common causes of smoke might be tobacco smoking, bonfires, wood or coal fires lit for the purpose of keeping warm, traffic fumes, wildfires, house fires and… burnt toast.

Traffic fumes

How much is too much?
Traffic fumes can contain a complex mixture of substances, many of which are toxic. Some of the things commonly found in traffic fumes include fine smoke particulates, polycyclic aromatic compounds, nitrogen oxides, formaldehyde, carbon dioxide, carbon monoxide, VOCs and much more. An interesting “partial list” (which is itself quite long!) from the Occupational Safety & Health Administration, of substances which are commonly found in diesel exhaust fumes, may be found here. It’s quite a complex cocktail!

A recent study has found that diesel exhaust fumes kill throat cells and that interestingly, biodiesel fumes are less harmful to our health than regular diesel fumes. Another reason to go bio-diesel!

Another study has found that traffic fumes cause damage to DNA. Depending on how close to urban areas/road systems you live, traffic fumes could be entering your home. Also, you may be interested in investigating air filters for your car: There are products on the market now that run by being plugged into the car cigarette lighter socket and provide air purification while on the road – could be great for those long freeway journeys or commuting in heavy traffic.

Tetra-Ethyl Lead, once in common use, has now ostensibly been phased out of use as a gasoline additive. It is still available in a few countries, but the concerns over its toxicity led to its withdrawal. The United States Department Of Energy has an interesting page on advanced combustion engines which are intended to cut emissions of toxic substances. Sounds good!

Now electric cars are beginning to be seen on the roads of the world. Observing the amount of traffic on the roads, and the incessant rat-race of our “modern” lives, it looks as though it will be many years before that glorious day in human evolution comes when traffic fumes are a thing of the past! Perhaps our descendants will picture us, fleetingly, thinking “How wonderful life is in the 23rd century!” – before they turn back to their paradise-like experience and their hyper-pure air, swatting our unpleasant memory from their minds as we would swat a fly.


It’s such a shame that something as pretty (see below) as Pollen grains can cause problems. Pollen is microscopic grains produced in the male parts of flowers. Plants use pollen as a way to reproduce. “Pollen counts” (i.e. the amount of pollen in the air) are greatly increased during flowering seasons of plants. Usually, this is in spring and summer – but flowering season varies depending on the type of plant, the climate, and the geographical location.

Allergy to pollen is commonly known as hay fever. Pollen from some plant types is smaller and lighter – and therefore can be carried further by the wind.

How big are pollen grains?

According to this article, pollen grains commonly range in size from 3 to 200 microns. Thus they would seem to fall well within the range of particle sizes likely to be caught by HEPA filtration.

air purifiers market


Molds are certain microscopic species of fungi. There are thousands of species. Like other fungi, they live and feed off organic matter. Molds reproduce through spores – minute particles which are released and float through the air. These tiny fungal particles are commonly believed to cause allergic reactions and health problems in some people when breathed.

Here at we personally know people who have had symptoms that they are convinced have been caused by mold – and, feeling that the mold is “in the house”, have moved house due to their quest for improved health.

This was obviously a very drastic step, and who knows whether the problem could have been more easily solved – or whether it was even the mold that was making them sick? However, it stands to reason that if you have mold in your house, or suspect that you have mold symptoms, you might want to do something.

A few mold prevention tips

Molds love damp conditions as they require moisture – either in the air or on the surface where they are living. Certain air filters may be beneficial in removing mold spores from the air and relieving symptoms, but the primary cause of indoor mold is damp conditions and to alleviate mold it is often recommended to resolve the cause of humidity first. Damp can often be caused by water pipe leaks, flooding, leaking roofs or gutters, leaky washing machines / washing machine pipes, or “rising damp” if a dwelling lacks a “damp course” – usually found in the lower part of the ground floor wall.

A common cause of mold that can often be overlooked is the simple “blocked gutter.” This can easily be caused by falling leaves if the house is near trees – and if the gutter is blocked, water can spill down the side of the house instead of flowing down the pipe as it is meant to. Water soaking through the walls of the house can lead to mold. So in this case, the best solution is to make sure the roof gutters are free from debris – especially during or after the fall of leaves. This will generally require that someone goes up a ladder. Note – ladders can be dangerous – here is an article on ladder safety.

Another very common cause of mold is insufficient ventilation in bathrooms/shower rooms. Notice how damp the walls, mirror, windows, ceiling become after you have taken a hot shower? These are the kinds of conditions that molds love. Switch-operated fan ventilation is a common solution for bathrooms – but not all old houses have this fitted. In this case, try to remember to open the window for several minutes after steaming up the bathroom.

Even if you do this, the general amount of moisture in the air can lead to a moldy bathroom. That good ole’ nasty shower curtain is an infamous mold source – so the first step towards mold removal is to find one that is machine washable…. and don’t forget to wash it every so often!

We’ve given a few examples but there are many possible ways mold could be caused.

From our research, it appears that a good way to approach mold might be first to tackle humidity problems first, clean up the existing mold – and filter existing spores from the air. However, if your house has serious mold problems, professional assistance may be required. The EPA recommends that any area of mold larger than 3 feet square should be professionally treated.

air purifiers

Volatile organic compounds (VOCs)

What are Volatile Organic Compounds / VOCs?
VOCs are organic chemical compounds which evaporate – either partially or completely. Thousands of manufactured products emit VOCs, and some of these may have adverse health effects. Examples of some of the many products which may emit VOCs include some types of carpet, paint, wood preservatives, plastics, building materials, cleaning agents, solvents, air fresheners, solvent based adhesives, permanent marker pens, cosmetics, and petroleum.

VOCs can often be found in higher concentrations in indoor environments than outdoors. VOCs such as benzene may be produced by photocopiers and printers when in use. Depending on their concentration, some VOCs are widely believed to have detrimental effects on human health. Some are suspected or known carcinogens.

Among the VOCs believed to be more dangerous to health are Benzene, Perchloroethylene (dry cleaning fluid) and Methylene Chloride a.k.a. Dichloromethane (found in some spray paints, paint strippers, and adhesive removers).

The subject of volatile organic compounds is an extremely complex one, as there may be numerous different VOCs floating around in low concentrations in human environments – and it is thus hard to ascertain exactly how harmful they are. However, contamination of the air by VOCs has become a major subject in the discussion of air quality and health – and concern has increased greatly in recent times over the increase in exposure to chemicals in the modern world. Opinions are diverse as to the level of harm caused by “low-level toxicity”. There has been an increase in reports of multiple chemical sensitivity in recent years.

Certain types of Air Purifier, such as activated carbon filters, are designed to remove VOCs from the air. One volatile organic compound that has received much attention in recent times is Formaldehyde.

Bacteria and viruses

Bacteria: Not, as some would have it, the back door of a cafeteria, but unicellular organisms. Of the innumerable types of bacteria in the world, some are harmless, even beneficial to the human system – and some are pathogenic; and such pathogenic bacteria can cause diseases such as anthrax, cholera and bubonic plague.

Being, as they are, often only a few microns in size, bacteria are often airborne. Viruses, generally, are smaller than bacteria – any many are between 0.01 and 0.3 microns in diameter. By definition, they require a “host” organism within which to grow or reproduce. So it stands to reason that if we are attempting to create an environment that limits the spread of bacteria and viruses, we might wish to discover whether certain types of the air purifier can help.

Another method of removing bacteria and viruses from the air is UV light – and we find UV to be installed in several models of air purifier. UV has been in use in antibacterial and anti-viral applications for many years. So in short, it does appear that certain air purifiers are designed specifically to remove bacteria and viruses from the air.

air purifiers HEPA

Final Words

Indoor air quality can be adversely affected by many things that you do on a daily basis. Things such as smoking, owning pets, leaving windows open, keeping shoes on in the house, not vacuuming, cooking on gas stoves, and many other practices can all lead to deterioration of the air quality in your home or office. While it is possible to mitigate some of these effects by lifestyle changes, many causes of poor indoor air quality are simply out of your control or impractical to change. By using a HEPA air purifier, it is possible to greatly improve the quality of the air you and your family are breathing for the majority of your day. This will ultimately end up benefiting your family’s health tremendously.

What kind air purifier really works?

High-Efficiency Particulate Air filters, more commonly referred to as HEPA filters, are composed of randomly arranged fibers (typically fiberglass) in a mat of a particular thickness. Air is directed through the mat of fibers and particles in the air are trapped in the filter matrix. HEPA air filters have the ability to trap very small particles and are thus one of the best tools in eliminating allergens and contaminants from the air in your home/office.

A HEPA air purifier is an investment in both the present and future health of you and your family. Breathing clean, fresh, uncontaminated air just feels better! If you have read this far it is safe to assume that you think you may benefit from adding a HEPA air purifier to your home. I encourage you to read some air purifier reviews, browse the various model’s features and capabilities, and add a HEPA purifier to your home/office today!

Air Filtration Options

Peace of mind is something that people will often find themselves working toward on a constant basis all throughout the course of their lives. However, this is a continued struggle for most people simply because they do not have any idea when it comes to how best to give themselves the type of basic feelings of contentment that they are in search of. As you know, quality of food and water are two of the most important things that any human being can have.

In the event that you are in the position of accepting either of these in the form that is not up to your needs, it is important that you address the issue as quickly as possible. Every bit as important as the food you are taking in would be the quality of air that you are breathing each and every day. However, many people tend to assume that they have limited control when it comes to the quality of air within any space. Instead of looking into available solutions, it becomes a lot easier to engage in a course of action that is based upon simply accepting the space with the air as it is at the moment.

There are millions of people that suffer from allergies due to things such as dust, mold, and pollen. These things could become triggers for allergy attacks that could lead to severe health problems and expensive bills. It is important to understand that suffering from allergies is not a choice that you get to make, it is simply the luck of the draw. If your system does not respond well to these things, it is important that you take the time to see what could be gained through some of the most popular air filtration products on the market today.

When you put an air purifier into the space that you are spending the most time, you would find that it becomes a lot easier for you to relax within your home. It becomes easier for you to get a good night of sleep and simply spend time within the environment without having to worry about being made to suffer. The quality of your air is not something that you should ever take for granted. No matter if you are searching for a solution for home or a larger space, there are some cost-effective industrial air filtration options that would be well worth the money.

People deserve to be able to enter your place of business and know that they can enjoy clean air while they are there. If you upgrade the technology that is filtering your air within this space, it is likely that your customers will notice the difference and spend money here more often than they do at the moment. However, it is important that you do not overlook the importance of clean air. Instead, it is possible for you to enjoy the latest technology within the field at a price that is going to secure your peace of mind.

true HEPA air purifiers

Air Purifier Terms Glossary

HEPA filter / “true HEPA” filter

HEPA stands for High-Efficiency Particulate Air or High-Efficiency Particulate Arrestance. A HEPA filter is a highly efficient form of air filter which is designed to remove very small particles from the air. HEPA filters are often used in commercial and residential air purifiers, and in vacuum cleaners – as they excel at removing particles such as pollen, mold, and dust from the air. HEPA filters are also often found in medical applications – a good indicator of their quality. Please see our full article on HEPA filters for more info.

ULPA filter

ULPA stands for Ultra Low Penetration Air. An ULPA filter by definition removes 99.999% of particles .00012 of a millimeter in size. Serious stuff! ULPA filters have an even higher rating and filtration effect than HEPA filters and are some of the highest grade filters around for removal of particulate matter from the air. However, because the ULPA material is denser than that of a HEPA filter, airflow is more restricted – meaning less air circulation. ULPA units do not necessarily perform as well as HEPA units in providing particle-free air as they may not “change the air” in a room as frequently as a HEPA unit – due to restricted airflow.


HVAC stands for Heating, Ventilation and Air Conditioning.

Ionizer / Ionic Air Purifier

An Ionizer / Ionic Air Purifier produces negatively charged “ions” – electronically charged air molecules which attract dust and other particles. This has a cleansing effect on the air as the particles which have clumped together fall from the air. The fact that this works can be demonstrated – as dust can be seen to collect near an air ionizer after it has been switched on for a while. Ionizers are quiet in operation but recent research and consumer reports have claimed that ionizers do not perform anything like as well as HEPA filters in cleaning the air. Also, they are believed to produce small amounts of ozone, a lung irritant.

However, some believe that negative ions themselves have health benefits and may counteract the positive ionization of the air caused by other electronic devices. Here at air-purifiers-online though, we have to say that we are “bigger fans” of HEPA filtration.

Electrostatic / electronic air cleaners

These use electricity to charge particles in a similar manner to an ionizer. These particles then collect on plates charged with the opposite charge.

Gas Phase Air Filter / Activated Carbon Filter

Also known as air scrubbers, these are used to remove Volatile organic compounds (VOCs), solvents, tobacco smoke, gases and odors from the air.

The most common Gas Phase Air Filter is the Activated Carbon Filter. Activated carbon is a type of carbon that has been specially treated with Oxygen in order to open up pores between the carbon atoms and create a form of carbon with an enormous surface area – hundreds of square meters of “bonding sites” per gram! This means that chemicals which are “attracted” to carbon (such as chlorine and many VOCs) will have a great opportunity to be “absorbed” by it. However, not all chemicals react with activated carbon and some will pass right through.

It stands to reason that the most effective activated carbon filters will be ones which contain the most activated carbon! These, however, are thicker and are therefore more resistive to airflow. Some ACFs currently on the market contain many pounds of activated carbon.

Activated carbon is also not suitable for removing dust from the air and so is often used together with HEPA filtration for an overall combined air filtering effect. Also, as already noted, activated carbon filters will not remove every type of gaseous pollutant from the air. In particular, carbon monoxide may be left behind.

Thus activated carbon is often mixed with other substances which remove other types of gaseous contaminants from the air – such as Potassium Permanganate (which is intended to remove formaldehyde, hydrogen sulfide, and sulfur dioxide). Such products would appear to be able to address a wider range of gaseous pollutants. However, some say that Potassium Permanganate filters can possibly release Manganese into the air.

Zeolite (intended to remove ammonia) is also sometimes included in activated carbon filters but its effectiveness has been strongly challenged.

Ultraviolet Germicidal Irradiation air cleaners

These use UV light to kill viruses, bacteria, and molds and are commonly used in HVAC systems in conjunction with particle filters such as HEPA. Ultraviolet light is a well-known method of sterilization and has been used for this purpose since the 1930’s.

Photocatalytic Oxidation cleaners

These use UV light in conjunction with a catalyst to convert harmful gases into harmless substances, but the United States Environmental Protection Agency states that their effectiveness is not currently sufficient for home air purification uses.

Ozone generators

These create ozone but are highly controversial, since ozone is toxic and a lung irritant. Ozone generators are often used in cleanup processes after fires or crime scenes, but the United States Environmental Protection Agency has deemed ozone generators unsafe and ineffective for general use as air purifiers and strongly recommends that they are not used for general air purification purposes.

MERV rating

This stands for Minimum Efficiency Reporting Value – and is a scale measuring the effectiveness of air filters. The MERV rating scores filters in HVAC (heating, ventilating and air conditioning) systems from 1 to 16 – the higher the number, the more efficient the filter. Because the material used to make a true HEPA filter needs to be denser than that of a less efficient filter, true HEPA filters are not normally installed in HVAC systems. A true HEPA filter in such a system would cause too great a resistance to airflow – but according to the EPA, filters with a MERV rating of 7 to 13 are almost as efficient at removing small particles from the air. Standalone HEPA filter units are often less expensive to run continuously than an HVAC system.
“True HEPA” filters have a MERV rating of 17-20.

air purifier

MCS (Multiple Chemical Sensitivities)

Well, this one turned out to be more tricky to research than we anticipated. MCS is controversial – and some experts appear to be in disagreement as to whether MCS even exists!

By definition, MCS – Multiple Chemical Sensitivity Syndrome – is an increased sensitivity to certain synthetic chemicals and irritants which can lead to a wide array of symptoms. The general conception of MCS is that sufferers experience symptoms associated with exposure to levels of substances which do not appear to pose such a threat to other people. Sources state that the onset of MCS might be triggered by an initial exposure which leaves the person “sensitized”.

Life for an MCS sufferer is said to be a nightmare – and may require them to live in an environment as free as possible from many chemical substances. This can, of course, be difficult because such substances are so commonplace in the modern world. It is interesting to note that some air purifier manufacturers such as IQAir appear to have addressed these concerns with some of their products – and have taken care to make air purifiers which do as little as possible to contribute to air pollution, through the use of special materials and construction.

MCS is a complex and controversial medical subject and thus is in many ways beyond the scope of this website. We have mentioned it for the sake of completeness but encourage readers to do further research and to seek professional medical care if they have symptoms.

Sick Building Syndrome is a condition whereby individuals may experience any one of a large number of symptoms, in association with a particular building. Out of a diverse number of possible causes, quite a number of them seem to be connected with contamination or poor air quality. Again, sick building syndrome is a highly complex subject.

7 Top Ideas and Tips for Improving Indoor Air Quality

1. Useless aerosols
Although they might make the air smell better, they are adding more substances to the air rather than getting rid of existing impurities.

2. Don’t smoke cigarettes
Stating the obvious? It still needs to be said. Tobacco smoke contains many carcinogenic substances and other toxic pollutants.

3. Ventilate
Allow outdoor air into your home. Instructions: Open window or door. There! Assuming, of course, the air outside your home is fresher than the air inside! If you live in a polluted city (or if you are allergic to pollen), it might be better to get an air purifier and leave the doors and windows shut!

4. Use a stand-alone HEPA filter unit
These are efficient at removing particulate matter from the air and may be more cost effective than running an HVAC system with filters installed.

5. Vacuum
Regular use of a modern vacuum cleaner, such as those with “cyclone action” and/or HEPA filters – these suck up the dust (and some of the dust mites!), and if there is less dust, there is less to become airborne! Dusting or sweeping may collect some dust but it also stirs some up, which we then breathe – and may potentially “move the dust around” to a certain extent rather than getting rid of it entirely.

6. Wash
Your fabrics! Wash bedding, curtains, cushion covers and other fabrics often. Use of a high-temperature wash such as 130 deg F (if this is ok for the type of fabric you are using) will help get rid of dust mites.

7. Construction
If you are doing construction or renovations, you might want to investigate which building materials will not “off-gas”. i.e. certain types of particle board and plywood use formaldehyde and this can escape. As the amount of “off-gassing” tends to decrease over time, it also might be worth “airing” new carpets, furniture etc. by leaving them in a garage or other dry, well-ventilated space for a while prior to installation.

Air Purifier Banner
Best Air Purifiers Buying Guide
Best HEPA Air Purifiers
Best Air Purifier for Allergies
Best Air Purifiers for Mold
Best Air Purifiers for Smoke
Best Air Purifier for Bacteria
Best Charcoal Air Purifiers
Best Air Purifiers for Dust

Related Guides
Best Air Ionizers
Best Air Purifiers for the Baby
Best Air Purifiers for Pet Owners
Best Travel-Size Air Purifiers