Best (Affordable) Air Purifiers For Indoor Air Quality


When I was looking for the right air purifier for my family, I quickly realized that they range vastly in price. There were many air purifiers that were only $20, while there were others that were $800 and above.

I’ll be honest with you – I was on a budget when I was shopping for my own air purifiers.

After doing my research, I decided that for my home and my family a good quality, reasonable air purifier is about $60 to $300, depending on the size of the room.

If you’re on a similar budget, keep reading and save yourself some time as I’ve already done the research for you.


The Air Purifier I Decided On For My Own Family

I first wanted to buy an air purifier for my living room, so I bought the Winix 5300-2 air purifier. My recommendations here will obviously be biased towards the Winix. You’re welcome to jump ahead to the place I bought from on Amazon if you don’t want to read the rest of my reasoning below.


What to Look For, Really

There are literally tens of thousands of air purifiers on the market, so it can be excruciating reading through all the product descriptions, trying to understand if the one you’re looking at is the right air purifier for you.

It’s actually very simple.

Look for standards that are made for United States consumers and be wary of incomplete, misleading product descriptions that don’t follow these standards.

Here are some things you definitely need to be looking for to make sure you’re not being misled or aren’t comparing air purifiers equally (which sadly, is rampant in this industry).


Air Changes Per Hour (ACH)

Before an air purifier can even start cleaning the air, it has to have a fan that’s powerful enough to move the air in the room. Don’t be fooled by manufacturers that just claim to cover a large room without any further information.

For example, the most commonly available air purifiers by RabbitAir (like their popular BioGS 2.0 and Minus A2) models cost well over $500, yet can fully cycle the air in a room only twice per hour.

When looking for an air purifier, always look at how many air changes per hour (ACH) the unit can produce for the given square footage. If it isn’t listed or is anything lower than an ACH rate of 3, pass it up. It just isn’t worth it to have an air purifier that can’t cycle the air fast enough.

If you have asthma or allergies, it’s recommended to have an ACH rate of 5 to 8 times or even more. Now, some of those ACH rates can be difficult to find at an affordable price for most of us, but I encourage you to take a look at the Honeywell line of air purifiers on Amazon to see what’s out there.

The company is very transparent and diligent in its product specifications, which I appreciate about it. Most of its air purifiers offer an ACH rate of 5, meaning that it can fully exchange the air in the listed square footage room once every 12 minutes.

Make sure that the manufacturer’s description tells you what the ACH rate is exactly. Many use wording like “refresh your air in x amount of minutes” without ever telling you the ACH rate, square footage, or any of the other features I will discuss next.


Clean Air Delivery Rate (CADR), In Cubic Feet Per Minute (CFM)

Once you have the ACH rate, you’ll need to couple this information together with the clean air delivery rate (CADR).

If you don’t have both of those pieces of information, I promise you that you won’t make a well-informed purchase decision.

So what is CADR?

CADR is a way to present airflow in cubic feet per minute (cfm) for three pollutants – tobacco smoke, dust, and pollen. The organization that administers the CADR testing standard, Association of Home Appliance Manufacturers (AHAM), then makes a recommendation of the suggested room size for those given results.

Manufacturers voluntarily participate in the AHAM test. You’ll often find them display their test results on the air purifier with the AHAM Verifide label. It looks something like this.


CADR Label Example for Air Purifier

An AHAM Verifide label.


A general rule is that the CADR needs to be about two thirds of the square footage of the room, assuming an 8-foot ceiling. So, a 300 sq. ft. room needs the CADR to be at least 200 for each of the three listed pollutants. If you want to find out the exact CADR rating your room or open space needs, you can find a useful table in this post.

You’ll find that the CADR is always lowest for tobacco smoke. That’s because smoke is considered a fine particle and is a far greater irritant than are dust and pollen. It’s also harder to filter out because of its smaller size, so its CADR is lower. If you have asthma or allergies, make sure your air purifier has a high enough CADR for tobacco smoke.


Beware of the M3/Hr CADR Ratings

If the product listing doesn’t have an AHAM Verifide label or doesn’t specifically mention anything about AHAM, yet gives you a CADR rating, pay close attention.

You’ll often find that many of those products list their CADR ratings in cubic meters per hour (m3/hr), not cubic feet per minute  (ft3/min). This makes the CADR number appear far greater than it really is compared the AHAM standard.

In their defense, some of those manufacturers of air purifiers are from overseas where the standards are just different. For example, take a look at Levoit’s air purifiers, which aren’t AHAM tested.  Their CADR ratings are in m3/hr, but they’re good products because their suggested room sizes are actually on par with AHAM recommendations. In other words, they’re being honest about the coverage their air purifiers can achieve.

But if you’re trying to compare two air purifiers side-by-side and both have CADR ratings, make sure to check the units and convert to ft3/min, or else you’ll be comparing apples to oranges unknowingly.

And sadly, not all manufacturers will be as realistic about the recommended room sizes as Levoit, Honeywell, Winix, and some of the other companies out there.

So be careful! Air purifiers that aren’t powerful enough for your room size will just waste your electricity and won’t even clean the air.


True HEPA (High-Efficiency Particulate Air) Filter

To really be able to filter out the majority of pollutants inside the air of a home, you’ll have to have a True HEPA filter. The reason why there’s a “True” in front of that is that there are a lot of manufacturers that are quite frankly misusing the term.

If you come across words like HEPA-like, HEPA-style, or other creative twists on the HEPA name, you may wish to think again before you make the purchase.

So what is the difference between the True HEPA and HEPA-like filters?

Oh, it’s huge. True HEPA filters out 99.97% of air pollutants that are 0.3 microns in size or larger, while HEPA-style filters out 99.00% of air pollutants that are 2.0 microns in size or larger.

If you think this isn’t a big deal, let me tell you that it is. The most irritating air pollutants (called fine particles) are less than 0.5 microns in size. Choosing a HEPA-like instead of True HEPA filter means that your filter isn’t able to capture cigarette smoke at all. Not to mention so many other pollutants that fall in this range of sizes, like bacteria, viruses, and even some mold spores.

Even a  True HEPA filter isn’t enough because it isn’t as effective at catching all pollutants fully. Volatile organic compounds (VOCs) completely pass through a True HEPA filter. That’s why almost every air purifier on the market now has an activated carbon filter, to catch those smaller particles. Activated carbon has small pores inside that are just the right fit for those small particles to fall into.

Together, a True HEPA filter and an activated carbon filter are more than enough to clean the air sufficiently in most homes.


Total Price of Air Purifier, Including Filters

It’s easy to get drawn into buying an air purifier because of its low price, but I encourage you to first consider what the cost will be long-term. Many manufacturers lower their prices on the initial product and then keep the prices high on the replacement filters. The Winix air purifier I bought costs $80 per year to replace the 5 filters inside if I go through the manufacturer’s website, but with my Amazon Prime membership, I’m (as of right now) able to buy them at $45. That’s not bad at all on an annual basis.

I also like that I am able to find these filters at several places, so I don’t have to worry about them being out of stock any time soon.

Here are the replacement filters I’m buying for my Winix 5300-2, by the way. It’s model 115115 and I buy it directly from Winix on Amazon. It includes 1 True HEPA filter that I change out once per year and 4 activated carbon filters that I change out once every 3 months.

This is pretty common for most air purifiers. You’d change out the True HEPA filter about once a year and the activated carbon filters every 3 months. It’s also common to replace the True HEPA filter once every 6 months or to just vacuum the activated carbon filters instead of replacing them every few months.

One thing I quickly realized is that there are “standard” (more like OEM) replacement filters that can fit more air purifiers than just the model I bought. It seemed enticing at first to save an extra $20 as these were so much cheaper. But as I kept reading the reviews, I realized that actually, these filters are a quarter of an inch smaller than what my air purifier needed, so I decided against it.

So, don’t be that person who has to duct-tape a gap in your air purifier just to save $20 per year. It significantly reduces the power of the air purifier and defeats the purpose of picking the right ACH, CADR and True HEPA filter.

Some more expensive air purifiers require you to buy each type of filter separately. Again, you’ll have to read the user manual to figure out how often each filter needs to be changed, and then figure out just how many total filters of each kind to buy throughout the year. For the air purifiers that are roughly in the $150 to $300 price range, you can expect each filter to cost about $10 to $20. So, if you have to buy 4 activated carbon filters and 1 True HEPA filter, you can expect to pay about $50 to $100 per year, roughly.

One thing to be aware of is replacement filter kits. Some manufacturers will knowingly try to sell you 1 True HEPA and 1 activated carbon filter in a kit when they very well know that one of those filters will be changed more frequently. Unless you’re getting a great deal, it’s probably best to buy each kind of filter separately.

Also, stay away from manufacturers that put all filters into the same filter frame. You may come across them – it’s a single filter that usually has a HEPA side and an activated carbon side. This has two problems. First, HEPA filters need less frequent change than activated carbon filters, so it doesn’t give you the control you need to change each type of filter at the right time. And this leads to the second point, which is that changing filters more often than you need to can be more expensive.


Proof That There’s No Ozone Being Produced

The next step in picking the right air purifier for you is to eliminate the ones that produce ozone.

Ozone generators are the easy way to eliminate air pollutants. They’re also cheap, so air purifiers that rely on ozone to clean the air are also the least expensive ones out there on the market.

But before we go any further, we have to understand some common terms that you may come across.

Ozone – a molecule with 3 oxygens bonded to each other, otherwise known as smog. It’s harmful to our health because it causes lung irritation and breathing difficulties. It worsens the symptoms of those who already have allergies, as well as those who have respiratory infections or an otherwise frail respiratory system.

Ozone generator – any device that has been shown to produce ozone.

Ionizer – a device that breaks up a molecule into positive and negative ions. This is a natural process in nature and is actually good for you. Some ionizers, however, can produce ozone.

Negative ion generator – another term for ionizer.

Ionic air purifier – an air purifier that also has an ionizer.

Now, just because an air purifier has an ionizer function doesn’t mean that it’s dangerous and will produce dangerous levels of ozone. If you’re still worried, it’s best to buy an air purifier that lets you turn this option on or off as you wish. That way, you can turn it on while you’re out of the house.

Another thing you can look for is emissions tests for ozone. A manufacturer cannot deliberately claim that their air purifier is ozone-free without a way to back that up. Look for CARB-certified products – that means that they have been independently tested according to California’s air emissions standards (one of the strictest standards in the world).

The Winix air purifier I bought uses what they call PlasmaWave technology. This is an ionizer that specifically creates hydroxyl ions. The hydroxyl then attaches to the other reactive pollutants in the air, thus removing them. This is a safe process since it happens in nature anyway. I run mine about once a week and it does a great job.