What Does an Air Purifier Do & How Do They Work?

Indoor air purifiers have become incredibly popular in recent years in America, but what exactly do they do, how does an air purifier work and why would you want to have one in your house or apartment?

Ahead is just how polluted the air inside your home can be, how using new air cleaning technology can help, the many health benefits of air purification and important factors when considering whether an air purifier will work for you and your family.

What is an Air Purifier & Why Would You Need One?

An air purifier is a portable appliance specifically designed to remove floating contaminants, like dust, mold spores, pollen, pet dander and other allergens, from indoor air.

The air that you breathe in your home can be up to 5 times more polluted than outdoor air, according to the EPA. Every time you take a breath you are breathing in some of these airborne irritants into your lungs.

Asthma and allergy symptoms, like shortness of breath, coughing, nasal irritation, congestion, itchy and watery eyes and a runny nose, are just some of the more obvious signs of inhaling polluted air.

Even if you aren’t aware of obvious respiratory issues, regularly breathing in excessive fine particles can negatively impact your health, leading to low energy, an irritable mood, difficulty sleeping and poor immunity with more regular colds and flu.

Some research studies and health authorities even list air pollution as a significant risk factor for serious, yet seemingly unrelated diseases like cancer, cardiovascular disease and other life-threatening illnesses.

With the air you breathe so important for overall health you can see why it’s good to know what an air purifier is, how it works to improve air quality and why you might need one in your home.

What Does an Air Purifier Do?

While they vary greatly in size, design, effectiveness and price range, the primary purpose of any air purifier is to filter, neutralize or clean the air of floating allergens, pathogens and toxins that can cause health problems.

A good air purifier should be able to quickly clear the air in your living room, bedroom or other indoor space of contaminants like dust particles, pollen, pet dander, mold spores, bacteria, viruses and cockroach, rodent and dust mite waste products that float in the air.

Certain types of air cleaners can also work to remove cigarette smoke, mustiness, pet odors, cooking smells and other bad smelling gases, as well as volatile organic compounds and various chemicals and irritants from off-gassing paint, carpet, furniture and electrical equipment.

Pollution from outside air can also be significant, with carbon dioxide, ozone, sulphur dioxide, particulate matter and other indicators of poor air quality in major cities in the USA regularly reaching dangerous levels.

Most people who live in populated areas with polluted air and have modern furnishings in their homes can benefit from the air cleaning power of a well-designed air purifier.

If you have asthma, allergies or other breathing difficulties, or if young children, pets, cigarette smoke, pollen, mold, fresh paint or new furniture is a factor in your home then you will likely have special needs to consider when buying an air cleaner.

How Do Air Purifiers Work?

Air filters and cleaners use different types of technologies, often in combination, to cleanse the air of pollutants and make it healthier to breathe. The main air cleaning methods include HEPA filters, ionization, activated carbon, UV light and ozone.

It’s important to consider the different types of air purification systems available and what is most suitable for the individual needs of your family when looking for an air cleaner to buy.

To understand this, let’s take a look at the 5 main types of air purifiers and just how they clean and filter the air you breathe:

5 Main Types of Air Purifiers and How They Work

1. HEPA Air Filters

High-Efficiency Particulate Air (or HEPA for short) purifiers suck in air and filter it through a fine mesh of fibers that trap contaminants as they pass through it.

An internal fan is used to circulate the air in the room and pull it through the filter, though the best HEPA air purifiers are designed to keep noise to a minimum.

True HEPA filters can remove up to 99.97% of particles to 0.3 microns, making them highly effective at neutralizing airborne dust, pollen, pet dander, mold spores and dust mites. They can even pull floating bacteria and viruses from the surrounding air, creating a much healthier breathing space.

Where HEPA air purifiers aren’t particularly effective is at removing chemicals, odors and volatile organic compounds from the surrounding air. This is why they are often combined with an activated carbon filter.

2. Activated Carbon Air Cleaners

Sometimes also called an activated charcoal filter, this method of air cleaning utilizes a special form of carbon that is extremely porous and highly effective at trapping chemicals and gases within its structure.

Tobacco smoke, mustiness, cooking odors and pet smells can be quickly dealt with by using an activated carbon filter in your air cleaner. It is also very good at absorbing formaldehyde and other VOCs and toxic chemicals released by paint, upholstery, curtains and carpets.

Activated carbon air purification works best in combination with a HEPA air filter and many bestselling and highly recommended air cleaners use this combination.

3. Ultraviolet Air Purifiers

A more specialized method of air cleaning involves passing circulating air through a strong UV lamp. This is best used for killing viruses, bacteria, mold spores and other floating microorganisms.

It isn’t effective for dust and other larger airborne particles, or at eliminating odors, so it is most often used in conjunction with both HEPA and carbon filters as the last stage of air purification.

4. Air Ionizers

Air purifiers that generate negative ions work to clean the air in a completely different way to the methods discussed above.

A current of electrons is passed down a needlepoint and discharges negative ions into the surrounding air. These negatively charged ions are naturally attracted to positively charged airborne particulates like pollen, pet dander, viruses, bacteria and mold.

As more and more negative ions attach to floating allergens they become too heavy to stay airborne and drop to the floor or a nearby surface where you can no longer breathe them in.

Negative ions have other benefits beyond air cleaning but unless they combine air circulation they do tend to have a limited range.

While they are often more cost-effective than HEPA filters, it’s important to make sure they don’t generate ozone beyond the safe 0.05 ppm recommended by the FDA. In fact, a good air ionizer should clearly state ozone levels below the detectable range.

5. Ozone  Generators

Ozone (O3) is a highly reactive and unstable oxygen molecule that has limited uses as an air cleaning technology and should only be used with precautions.

Ozone is very effective at destroying airborne mold, mildew, viruses and bacteria. It will also quickly eliminate strong odors and chemical smells, leaving a crisp air freshener smell in its place.

Unfortunately, ozone is also a known lung irritant and in high enough concentrations can be very unhealthy to breathe in. It should be especially avoided by asthma sufferers and people with breathing problems.

Most ozone-based air purifier manufacturers will tell you they adhere to the safe limit set by the FDA of 0.05 ppm, however some testing has shown cheaper models in particular exceeding this. They also often use names like anion air cleaner and ionizing air purifier when in fact they are primarily using ozone, not negative ions.

While ozone generators may be useful in specific cases, like before moving into an extremely smelly home, the best recommendation is to use a HEPA based air filter in larger rooms or a negative ionizer for closer air cleaning and avoid air purifiers that use ozone.

Top 10 Air Purifier Benefits

1. A well-designed air purifier with a HEPA filter will trap 99.97% of floating dust, pollen, pet hair, mold spores, dust mites and other airborne contaminants. Even if you don’t have any obvious respiratory problems these irritants can lead to tiredness, lowered immunity and more susceptibility to disease
2. If you are one of the estimated 50 million Americans affected by seasonal allergies and hay fever then air purifiers can work especially well to capture allergens like pollen and prevent symptoms like sneezing, watery eyes and sinus attacks.
3. Asthma suffers can really benefit from an air purifier working in the room they spend the most time in. True HEPA based air filters are highly recommended for people with asthma and may even help protect sensitive young children from developing asthma.
4. If your air cleaner has an activated carbon filter it will also work well to remove bad odors and chemicals like formaldehyde and other VOCs from the air you breathe. This is very important for people with multiple chemical sensitivity (MCS). Negative ionizers can also be effective against VOCs at close range.
5. Cigarette smoke can be an especially persistent bad smell and very unhealthy for young children to breathe. A powerful air purifier is recommended to eliminate tobacco odors if someone smokes and remove it from the air before it gets into carpet, curtains and upholstery.
6. Pets like dogs and cats usually leave a lot of hairs and dead skin cells in the areas they live which can be a strong irritant when you breathe them in. Microscopic animal parasites and of course pet odors are also a problem. Air purifiers work to deal with all of these challenges and make the air cleaner for both you and your dog or cat.
7. Airborne mold spores are a serious yet under appreciated health problem. When you breathe them in they can attach to your lung tissue and cause a whole host of respiratory issues. HEPA air filters are considered highly effective at trapping mold spores and UV technology can provide extra protection against the dangers of mold and mildew.
8. When someone with a cold, flu or some other viral disease coughs or sneezes they send out viruses into the air attached to fine water droplets. High-quality air filters can trap most of these viruses, along with airborne bacteria, but for extra protection an air purifier with a UV germicidal lamp is recommended.
9. Cleaner air helps you sleep better and be more energetic and productive the next day. Using your air cleaner in your bedroom will also help to filter the air of dust mite feces and other allergenic particles, allowing you to get a better night’s sleep.
10. With the EPA estimating that the air in most people’s homes is around 5 times more polluted than outdoors, a good air purifier is a wise investment. It ensures your family is breathing clean air, keeps your lungs healthy, removes odors, prevents allergies and asthma attacks and contributes to overall better health and wellness

Do I Need an Air Purifier in My Home?

With the pollution levels in large towns and cities, combined with all the potential allergens and contaminants within modern homes, most people can benefit from the air filtering power of a well made air purifier.

In some cases, you may have specific requirements to take into account, and it’s important to know just what you need your air cleaner to do before buying one.

There are, however, a few reasons where an air purifier might not work for you. Consider your personal situation below and if you need an air purifier or whether it would be a waste of money.

8 Reasons Why You Should Get an Air Purifier

1. Someone in your house or apartment suffers from asthma, allergies or other breathing problems.
2. You have trouble sleeping and want to make sure the air in your bedroom is free of irritants like dead skin particles and dust mite waste products.
3. Mold or mildew is an issue in your home, especially during winter. A good air purifier will remove dangerous airborne mold spores.
4. You have problems with cooking odors or chemical smells, particularly from new furniture or electrical equipment. While pungent food isn’t nice to smell, chemical fumes can be quite toxic and are best removed with an activated carbon air cleaner.
5. You have pets like a dog or cat and want to eliminate allergenic pet dander and offensive odors.
6. There is a smoker in your home and you want to filter away tobacco smoke for both the bad smells and the negative health effects.
7. You live in an area where pollen like ragweed causes seasonal allergies and want to use a HEPA filter to capture it before you breathe it in.
8. You just want healthier air for you and your family and all the many health benefits of not breathing in oxygen contaminated with microscopic particles and other allergens.

3 Lifestyle Factors that Mean You Probably Don’t Need an Air Cleaner

1. You’re living in a rural or country area with naturally pure air and keep the windows open for good ventilation.
2. You clean regularly with natural, non-toxic cleaning products and don’t have issues with mold, pollen, pets, chemicals like VOCs or cigarette smoke and other odors.
3. You are exceptionally healthy and your immune system can easily deal with breathing in airborne particulates and gaseous contaminants.

Do Air Purifiers Really Work to Clean the Air?

Hospitals, universities and large US Government departments like Homeland Security use and recommend air purifiers, particularly HEPA based air filters, with good reason.

Scientific studies show that air purifiers do really work to clean the air you breathe of harmful particles and contaminants. Research like this study demonstrated that HEPA air filtration alone dramatically reduced the concentration of fine particles detected in bedroom air.

Having an air purifier doesn’t mean that you’ll never have to clean again or that absolutely all air pollution will be eliminated, but a well designed HEPA air cleaner can certainly make a dramatic reduction in the number of airborne contaminants you breathe in each day.

Add in a strong activated carbon filter, germicidal UV lamp and mood-enhancing negative ions and your air purifier should really work to remove the vast majority of allergens and keep your lungs healthy.

If you care about the quality of the air you and your family breathe each day and your long-term health it makes sense to consider the many health benefits of air purification for your living space.

I hope this article has helped to make clear what an air purifier is, what they do, and whether you need one in your home.

Please feel free to leave comments and questions about indoor air cleaning and how air purifiers work in the comments below.

Resources

• Air Purifier Buying Guide ― 7 Important Questions to Answer
• 10 Surprising Sources of Household Pollution
• 7 Indoor Allergy Triggers Within Your Home