Skip to main content
These days you can walk into almost any store and see some sort of air purifier for sale. There are big ones that look like industrial machines, high-tech ones with lights and digital displays, and little ones to wear around your neck. And the claims they make!
- Zaps viruses
- Destroys mold
- Kills dust mites
- HEPA-like
- True HEPA
- Medical HEPA
- Sanitizes the air
They slice, they dice, they play FM radio! Well, okay the last part is made up but you get the idea.
With so many machines on the market, they must do some good. Right? If you buy one, will an air purifier really help your allergies? How much you ask? The answer is, it depends.
An air purifier can really help your allergies if you have environmental allergies and you have the right type of machine for the size of the room you want to use it in.
Here’s how an air purifier can help your allergies.
An Air Purifier Can Help with Indoor Environmental Allergies
If you have indoor environmental allergies the right air purifier can help. Indoor environmental allergies are caused by things like:
- Dust
- Dust mites
- Molds
- Pet allergens
- Cockroaches
The right air purifier can also remove irritants like smoke, odors, and VOCs (volatile organic compounds). These aren’t allergens, but they can make it hard to breathe. So, if these are the things that bother you, then an air purifier can really help with your allergies.
If you are allergic to pollen and have seasonal allergies an air purifier might provide a little bit of help. But there are more effective ways to get relief from seasonal allergies.
Indoor allergens float on the air, fall, and stick to surfaces. As we move around a room, run a fan, sit down or get up from furniture, pick things up and set them down we send settled allergens back into the air to circulate and fall again.
"Can't say enough good things about this air cleaner (Austin Air HM400). Well made, quiet and works great. Expensive but worth it. Wish we would have known about you years ago. We have spent so much money on pieces of junk over the years." Richard
The air purifiers help with allergies by grabbing the allergen particles when they are floating and trapping them. Once trapped they don’t get a chance to float again. That’s important because only the floating particles are inhaled. The settled ones don’t cause a problem until they float and get inhaled.
An Air Purifier Can Help with Allergies if it is in the Right Room
So, here’s the thing. No air purifier can help with your allergies if it put it in the wrong room. You probably think the living area or area where you watch TV is the logical choice. But that shouldn’t be the first room you worry about. Even if you binge on Game of Thrones or House of Cards you really don’t spend that much time in the living room or den.
You spend one-third of your entire life asleep! That’s right you spend as much time sleeping as a cat spends grooming. And cats groom a lot.
When you go to bed, you spend from 7 to 10 hours in one spot. Even more, if you watch TV or read in bed before you go to sleep. So, if you want to get the most benefit from your air purifier you have to put it in the room where you spend the most time.
"We researched air cleaners for over a week and finally decided on the Austin Air HM400. It is truly the best unit available. We noticed a difference within a couple of hours. Worth every penny." Samuel
An Air Purifier Can Help with Allergies If It Is the Right Type
In addition to a dizzying array of makes and models, air purifiers can use many different ways to clean the air. Some of these methods work for ridding the air of allergens, some don’t.
Ozone is created when an extra molecule of oxygen gets bound to the regular oxygen we breathe, which is two molecules of oxygen. Oxygen is great to breathe, but it isn’t really very stable. So that extra molecule of oxygen doesn’t stay bound for very long. It breaks loose and becomes a free radical.
That’s not good. In fact, air alerts are issued when the ozone levels outside get high. Ozone irritates the lungs. Unfortunately, too many air purifiers create ozone. That’s because the free radical in ozone has the ability to oxidize VOCs, break down odors, and kill germs.
Air purifiers that create ozone have the capability of making your respiratory problems worse. Never buy an ozone-producing machine. Reads labels and if you aren’t sure, ask before you purchase. An air purifier that produces ozone can’t help with allergies.
Short wavelength ultraviolet light in the 260 nm–270 nm range kills bacteria by disrupting their DNA, destroying nucleic acids, and disrupting their function at the cellular area. It’s frequently used for medical sanitizing. That’s because it is highly effective with continuous application.
That means the UV light must shine continuously on the organism to be effective. UV is incorporated into air purifiers to kill bacteria, but it will only work if the organism is continuously exposed to the light. UV light doesn’t remove the dead organism either.
So, here’s why an air purifier that uses UV light won’t really help with your allergies. First, in order for the UV light to do its job, it must shine directly and continuously on the particle to be killed. In the case of a bacteria (they don’t cause allergies) or dust mites (they do) the particle must sit directly under the light for an extended period of time.
Air purifiers are busy sucking air in, passing it quickly by the light and then sending it back out into the room again. The particle isn’t exposed to the UV light long enough to be effective. Even if a dust mite were to be killed by the exposure, it would still cause allergy problems because dead dust mites release just as much allergen as a living dust mite.
Ultraviolet light doesn’t remove particles from the air and is not effective in cleaning a moving air stream. An air purifier that uses UV light alone can’t really help with your allergies.
HEPA filtration is one of the most common ways air purifiers remove allergens from the air. HEPA is a measurement. The acronym stands for High-Efficiency Particle Air. It is a standard that was developed by the government when doing atomic research. They needed to stop the spread of airborne radioactive particles.
The standard means that 99.97% of all particles at 0.3 microns or larger are arrested or stopped. 0.3 microns is really small. A filter that fine is small enough to capture all of the common indoor allergens. It’s going to grab dust and dust mites, molds, pet fur and dander, cockroach bits, and any stray pollen that hitched a ride inside.
HEPA filtration is the gold standard for filtering the air of allergens. But, it must be true HEPA.
Beware of descriptions such as “HEPA like” “hospital-grade” or “HEPA style”. Those are just a few dodgy ways to get “HEPA” in there without meeting the standard. Read the labels and make sure the filter is a true HEPA filter. Make sure it removes 99.97% of particles greater than 0.3 microns. An air purifier with a legitimate HEPA filter will really help your allergies if it is the right size for the room.
Air Purifiers Must Be the Right Size
An air purifier can only clean the air if the air makes it to the machine. That means the air purifier must constantly be moving the air in the room. Moving the air requires a motor and a fan. These are mechanical parts and they are going to make some noise.
A good air purifier minimizes this noise, but a “silent” air purifier isn’t moving air. Even if the motor and fan were silent (unlikely) you should still hear the air move. Even the wind makes noise when it blows. Your air purifier is the same.
To determine the right size machine for the room, you need a couple of bits of information. First, you must know how much air is in the room. In case you forgot, the volume is calculated by multiplying:
Length of room x width of room x ceiling height
A 10 x 12 bedroom with standard 8-foot ceilings has 960 cubic feet (10x12=120 120 x 8 = 960). That’s important to know. If you only looked at the square footage, you’d think you just had to clean 120 feet. But that’s 8 times less than you really have.
Take a very close look at the machine you are thinking about buying. The technical specifications will tell you how much air the motor can move. This information will be expressed as a number and then CFM. For example:
Airpura Air Purifiers: 560 CFM integrated fan/motor
Austin Air Healthmate Regular: Speed (3) 400 CFM
Stadler Form ROGER BIG:
Honeywell doesn’t say how much air their motors use. They just tell you the square footage of the room the machine will clean. That’s useless information since some rooms have 8-foot ceilings, some have 10-foot ceilings, and vaulted ceilings can be 13 feet or higher. If you can’t get the specs on the motor, move along to the next choice.
Next, look at the technical specifications for the machine and find the amount of air moved by the motor. It will be expressed as a number with the letters “cfm” behind it. That means the volume of air the machine can filter expressed in cubic feet of air per minute.
To determine air exchanges, take the volume of air in the room and divide it by the cfm of the machine. That will tell you how long it will take to get one air exchange. Or, in other words, how long will it take for that machine to move all the air in the room through the filter once. To determine the air exchanges per hour, divide 60 (the minutes in an hour) by the number of minutes for one exchange.
You want at least 4 to 6 air changes per hour. 10 is great and more than 10 is more than great!
So, can an air purifier help your allergies? The answer is yes, provided you have indoor environmental allergies, you get a machine that uses a true HEPA filter and is the right size of the room.
Air purifiers also help control odors and can help with smoke. But, those are not their primary jobs. So, shop carefully to get just the right machine.
Oh, and be sure to leave it on all the time. Like a lightbulb, it only works when you turn it on.