How to Buy an Air Purifier

If you’ve made it this far, then odds are that you’re already convinced that you need to buy an air purifier for your home. Today’s article is meant to show you how you can buy an air purifier. However, if you aren’t convinced just yet, then I wrote an article entitled Do I Need an Air Purifier for My Home? Please be sure to double back here if you need to read that piece first so I can show you how to get one right!

Buying an air purifier is remarkably easy if you know what to look for. Buying an air purifier is as simple as just three steps:

  1. Find an air purifier (or three) that fits your needs.
  2. Find an air purifier in your price range.
  3. Buy it from a store or website that is trustworthy.

But there’s one big issue there. Actually, there are two. One problem is that you might not know what to look for in an air purifier. (I know I didn’t before I started researching them!) Another problem is knowing where you can buy an air purifier. I’ll address both those problems in this article and I hope it’s beneficial to you!

How Do I Find an Air Purifier That Will Work for Me?

Finding an air purifier that works for you can be broken down into three easy things: room size, filtration, and looks. Of course, this is a rather simplistic take on things, but it’s all you really need as you probably won’t be too particular on the nerdier side of things.

Price issues will be addressed in the next section, and that’s another important thing to consider. Please be sure to check that out before you make your purchase! I mean it.

Now, with that out of the way, I’m going to dive right on in with just the bare minimum of things you should look for in an air purifier. Again, there is a lot more stuff that you might want to know if you have particular things that you’re looking for, so if that’s the case, then please be sure to check out one of the below articles, or check out the search feature on this site for particular things you might be wondering about.

What’s the Best Air Purifier for Someone with Pets?

Which is the Best Air Purifier for Asthma? | The 3 Things to Look for in Air Purifiers that Can Help with Asthma

Is the Size of Room I’m Going to Put My Air Purifier Something I Need to Consider When I’m Buying an Air Purifier?

The size of the room (or rooms, in the case of adjoining and connected rooms) is one of the most important factors to consider when you are getting ready to buy an air purifier. While you can fudge on the numbers a bit, it’s not recommended that you do so if you want the best quality of air in your home.

Why Shouldn’t I Fudge the Numbers on My Room Size for My Air Purifier?

The reason why this is such an important thing is because the fan that cycles the air in the room in your room through your air purifier is only built to pull so much air through the machine. On top of that, the filters are only built to deal with so much air flow as well.

That means that your fan won’t be able to keep up, if you put an air purifier rated for a small room into a large one. Additionally, your air filters, which can be potentially expensive, might need replaced more often, which isn’t great for you.

But air quality is another factor that you need to consider. If you put an air purifier that’s built for 100 square foot rooms in a 500 square foot room, the overall air quality will suffer. The machine will not be able to keep up in any way, shape, or form. You might not be able to even notice a difference, which stinks. If there’s no air quality difference, then you basically just wasted your money!

So, long story short, you need to buy an air purifier that’s rated for the size room you are going to put it in. Don’t try to cheat the system because you’ll just be cheating yourself.

How Do I Know What Size Air Purifier to Buy?

It’s easy, just measure out the size of room that you want the air purifier in, and then write that number down. Once you’ve got it, you can search for air purifiers by that specific number! Air purifiers are built for all sizes of rooms, so odds are that you’ll find a pretty good match for the air purifier to your room.

If you don’t know what the dimensions of your room are, then you can just grab a tape measure (or even a ruler) and measure it. If you don’t have one on hand, then just get a really rough number and walk heel-toe-heel-toe in a straight line across the room and count the steps. Treat each step as one foot and you’ll get your room’s dimensions. You will have to take the width and length of the room and multiply them together. So, if you got 10 feet one way and 12 the other, then your room’s square footage would be 120 square feet.

If your room is an odd shape, then you might need to do some more math, but I’m not cluttering up this article with all of that today. Alas, you’re on your own if you want to get fancy!

Now that you’ve got your room’s size, you’ll know what to look for in your air purifier. I recommend rounding up and getting an air purifier that’s rated for rooms that are a smidge larger than the one you’re putting them in, but you can round down (a tiny bit) as well. Just know that you get what you pay for, though. Don’t shortchange yourself!

Do I Need an Air Purifier in Every Room of My House, or Can I Just Buy One?

If you want the cleanest possible air in your whole house, then you need to buy an air purifier for every room. However, if you’re not willing to buy one for every room, then you can just buy air purifiers for the rooms you spend the most time in. This will likely be your bedroom(s), home office, kitchen, dining room, and living or family room. Prioritize the rooms you spend the most time in (including the time that you’re asleep!) and get an air purifier for those rooms.

Related articles on air purifiers for your bedroom:

What Are the Top 7 Proven Reasons Have an Air Purifier in my Bedroom?

What Are the Benefits of Having an Air Purifier in my Bedroom? | Sleeping Better with Better Air

If you have allergies, wake up with a stuffy or bloody nose, or wake up feeling not quite 100%, then I highly recommend starting with getting an air purifier for your bedroom. I think everyone should get one in their bedroom, but it’s especially important for those people.

If you don’t have those issues, then there are stull good reasons to get an air purifier for your bedroom, but you might want to start with getting one for the rooms you spend your waking hours in so you can notice the difference in the air quality while you’re awake. If you buy a quality air purifier, you will notice that the air is a whole lot cleaner, which is surprisingly amusing and cool!

Does the Coverage Area an Air Purifier Provides Impact the Price I Pay?

The price for an air purifier usually goes up as the coverage area goes up. This is because everything needs to be bigger, better, and stronger to cope with the increased airflow and increased air filtration. While there are outliers, the general rule is that larger rooms need larger air purifiers that are costlier.

I find that the foot for foot coverage increases rather linearly, on average, with the larger room sizes. For example, an air purifier rated for 60 square feet will be 20 dollars–1 dollar per 3 square feet covered–while an air purifier rated for 300 square feet might be 100 dollars–again, 1 dollars per ever 3 square feet covered.

3 dollars is right around the average that I see for entry-level air purifiers and the nicer, more effective air purifiers are a lot more. But, if you’re buying an air purifier for really large rooms, then that square foot cost average is likely to cost, even if the air purifier if a whole lot better. I find that once you pass the 300 square foot level for an air purifier that the cost begins diminishing for coverage to dollar cost.

The best air purifier I’ve ever used costs 800 dollars and covers 1000 square feet, however, which actually puts it WAY below the average of 3 feet per dollar. Again, it’s the best machine I’ve ever used, and the reason why it can be below the average is because it’s treating such a large area. If you’d like to read more about that machine, then you can see my first article on it here: EnviroKlenz UV-C Air Purifier Unboxing and Setup.

That’s about it as far as room size is concerned for air purifier purchasing. Now onto the filtration types!

What Kind of Filter Does My Air Purifier Need and What Should I Look for?

If you’re in the market for an air purifier, then you should consider what you want to have filtered out of the air. If you’re worried about allergens and dust, then a HEPA filter or a water-based air purifier will be able to help you. If you want better air filtration, then there are several levels of HEPA filters, and there are quite a few different types of filters that can kill germs, remove odors, and even take care of VOCs and radon. I’ll briefly address a few of the things you might want in your first air purifier today and I’ll let you check out a few of my other articles here on to learn more.

What’s a Good Entry-Level Filter for My First Air Purifier?

If you’re just looking for the bare minimum for air purifier filters, then a water-based air purifier or an air purifier with a HEPA filter is a great start. Both filtration types are easy to work with, and both are usually pretty cheap too. A lot of entry-level air purifiers will even include activated carbon filters with their HEPA filters, which is great but not required for a first-time buyer who just wants to check out what air purifiers are.

HEPA filters will likely do a better job than water-based air purifiers, but water-based air purifiers don’t need replacement filters like HEPA filters do. Instead, all they need is their water basin to be emptied and refilled. If you’d like to read up on water-based air purifiers, you can do so here.

Both of the above filters (HEPA and water) are known as “main filters” and they are just that–your main filter. They’ll do the heavy lifting for your air purifier and any additional filter just helps them do that.

Additional filters include activated carbon, pre-filters, and even filters that use static electricity and various minerals and metals. These are all cool extras that aren’t 100% necessary for people who don’t have specific needs out of their air purifier, but they do allow the air purifier to greatly increase the quality of air it provides you. I personally recommend that you get air purifiers that have at least a few of these extras, a pre-filter in particular.

If you’d like to read more on the various types of filters, then you can check out one of the below articles:

How Important are Air Purifier Filters?

What is a Pre-Filter? Does My Air Purifier Need a Pre-Filter?

How Do Activated Carbon Filters Work in Air Purifiers? | 3 Things Activated Carbon Filters Clean from the Air to Make it Better for You

Now, all these extras are just that, extras. You don’t have to buy them, but they do offer extra benefits over a normal air purifier. Look for whatever you are comfortable getting and don’t get something if you don’t feel like getting it!

Should I Buy an Air Purifier for the Looks?

Looks should not be the first thing you consider when you buy an air purifier, but it is something that you might want to think about. Buying an air purifier for looks alone might let you down, it can look really pretty and not work well at all. As such, the air purifier’s ability to work well should be the first thing you worry about before you buy.

But let’s face the facts, there are some really ugly air purifiers out there. I get it.

But it’s my job to tell you that there are really pretty ones that don’t work whatsoever.

In the end, you need to find an air purifier that works, that’s the whole reason why you’re buying one. You aren’t buying an art piece, you are buying a machine that will clean your home’s air and help your household’s health. So, while looks are a contributing factor to your purchase, don’t let it be the very first thing you look for. You might just end up with a useless “art piece” that doesn’t clean your home’s air.

How Do I Find an Air Purifier in My Price Range?

Most online stores have a nifty little feature that lets you search by prices. Some have it as “Prices Low to High”, some let you put in ranges of prices. This makes things really easy for you to find something in your price range.

But, as I’m sure you know, low prices aren’t everything. Sometimes you need to shell out a few more dollars to get something that’s actually worth the price you’re paying. We’ve all picked something up that seemed like it was too good a price to be true, and then had it break that same day.

So, I will tell you right here right now that you should be willing to pay at least twenty some dollars for an air purifier for a 100 square foot bedroom. This air purifier here is one I’ve enjoyed using for several years now, and it just cost me 21 dollars when I bought it.

Sadly, inflation meant the price went up, so I can’t say exactly what its price is today, but you can check it here on Amazon.

This air purifier, despite being one of the cheapest air purifiers on the market, has served me very well, so it’s earned my recommendation a dozen times over. But there’s an issue with it–it’s not meant for larger rooms.

Sure, that’s not really an issue, but it is something I need to say before someone goes and picks it up to use in their million square foot mansion.

As I said previously, you have to buy an air purifier that’s meant for the size of room your putting it in and preferably one that’s rated for a room that’s slightly larger.

If you’re in the market for an air purifier then you can check out the list of Blueair air purifiers we recommend here, the water-based air purifiers that I recommend here, or you can browse our site and find the other air purifiers I recommend for the various problems that ou might want to be addressed in your home (such as humidity, which I wrote an article on here).

Beyond that, everything’s really up to you. It’s up to you on if you want to buy a cheap machine, an expensive one, one with great reviews, or one that doesn’t have any.

If you’re ready to shop around for an air purifier, I recommend checking out Medify’s site here, and also on Amazon here.

Where is the Best Place to Shop for Air Purifiers?

There are quite a few places where you can pick up an air purifier, including local and online stores. However, most air purifier manufacturers will sell their machines directly to you, the consumer, and that can save you money. That being said, the online shops will provide the largest selection of air purifiers that you will be able to pick from, which is very valuable as well.

Personally, I prefer buying stuff directly from manufacturers because of several reasons:

  1. There isn’t a markup from the middleman and the middleman doesn’t take a cut away from them.
  2. Manufacturers run sales on their sites, which can get you great deals that you won’t see on the other online shops.
  3. Manufacturers have newsletters that have deals, which means you can buy new machines and also replacement filters for better prices.
  4. Manufacturers might run subscriptions that makes it easy for you to get replacement filters.
  5. Sometimes manufacturers offer special bonuses that they can’t offer via the online shops.

Of course, there are reasons to shop on those online stores as well, but I’ve moved away from them over the past few years, as have many people who disagree with the companies’ ways of doing business. Additionally, I like the idea of putting more money into the manufacturer’s hands because that helps them make newer and better air purifiers and filters, and it also helps them provide me with better prices down the road.

But there’s a problem with buying straight from manufacturers, and that’s that you can’t trust everyone. Online stores have really carved their market from these well-founded fears of fraud.

I find that the best way to avoid fraud is to purchase things only from American companies and companies from a select few other nations that have stricter laws that protect consumers. These more trustworthy nations include Japan, South Korea, the UK, Germany, Italy, Sweden, Norway, and other first-world nations. Sadly, developing markets are known to have lots of fraud, so I don’t risk large ticket purchases, like air purifiers, with them.

Beyond trustworthiness, I also like to pick companies whose ideals and values are ones I like. One such air purifier company, which we’ve recently partnered with, is EnviroKlenz. Another company we work with, named AirThings, makes air quality sensors and we really like their mission.

I have enjoyed finding new businesses to recommend and to work with since beginning this blog, so I’ve found plenty who are great to work with, and a handful which I wouldn’t trust at any point in my life. As such, I’ve done my best to find the best possible companies for you guys to buy from and I like to think I’ve done a great job at it!

Thanks for the read, and please be sure to pick up an air purifier sooner rather than later! You’ll be surprised how much nicer it is to breathe the air in your home once you’ve done so!

Want to shop for an air purifier? Check out Medify’s site and Amazon. If you’re looking for specific recommendations, check out my list of my top picks here!

I’m constantly networking with other air purifier manufacturers, so this list will (hopefully) continue growing!

Jonathon Silva

Jonathan Silva is our longtime Air Purifier Essentials author. He has been writing on air purification technologies for his entire professional career.

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