Differences Between Air Purifiers Vs. Fans


Air purifiers might be something that a lot of people haven’t heard about. But, despite your not hearing about them, they’re actually remarkable common–Washington Post reports that one in every four Americans own one!

But what is an air purifier? Are they just fancier versions of fans? Are they even like fans? What are the differences between an air purifier and a fan?

Air purifiers and fans both work around the concept of using wind to circulate air, that’s why a lot of people think that they are one and the same. However, air purifiers do something that fans can’t do; air purifiers clean the air that goes through them, unlike fans.

Just about every air purifier has a fan built into them, since that’s how they move the air, but that doesn’t mean that they’re at all the same thing.

Fans are made just to move air around air purifiers, on the other hand, are made to clean the air (and they move the air in a room around in the process, but that’s just an added bonus).

Keep reading to find out more.

Is An Air Purifier the Same as a Fan?

Sure, there are some obvious similarities between air purifiers and fans, but they are anything but the same machine.

But why is that? What makes air purifiers so special?

Let’s look at the similarities between these two kinds of machines first, I’m going to lay things out in a table, since that’s easier for some people to compare things with (and because tables are pretty).

CharacteristicAir PurifiersFans
What is DoesPulls air in one side, sends it through one or more filters, cleaning it, and then shoots it out the other side.Pulls air in one side and immediately shoots it out the other.
Cleans the Air?YesNo
Gets Rid of Allergens?YesNo
Gets Rid of Odors?Yes (With Activated Carbon)No
Cools the Air?Yes, SomewhatYes
Safe to Use 24/7?YesUsually Yes
Quiet?YesUsually No
Price Point?$40 – $180$16 – $130

Now, I’m going to out and say that there are air purifiers and fans that are both WAY higher than the price range I put in, but there’s really very little point in spending the big bucks on those units if you aren’t taking care of rooms over 800 square feet.

Now, with that little tidbit said, let’s take a closer look at things.

First off, how do air purifiers clean the air if a normal fan can’t? What’s so special about their filters?

What makes air purifiers so special is their specially made filters–HEPA filters in particular. There are other filter types like activated carbon filters that get you even cleaner air, but a HEPA filter is a good starting point if you want an air purifier that works really well.

So, now we know at least what the name of the filter is that makes air purifiers special, but how do they work?

HEPA filters have dense fibers that are interwoven and prevent particles from passing through. A True HEPA filter will be able to capture 99.97% of particles as small as .3 microns. .3 microns is the size of a larger virus, so you can be sure that a HEPA filter is doing a ton to clean your air.

HEPA filters are effective at cleaning tons of things out of the air, here’s just a short list of some of the things that they can capture:

  1. Allergens
    • Dust
    • Dander
    • Pollen
    • And a Lot More
  2. Smoke
  3. Spores (Fungal and Mold)
  4. Some Odors
  5. Bacteria

And, again, there are a lot of other things that HEPA filters can capture. Some of the top-of-the-line units can capture stuff even smaller than .3 microns which, again, is incredibly small.

Now, if all the things HEPA filters do isn’t enough for you, just know that there are other filter types out there that can get you even cleaner air–most of these are done in addition to a HEPA filter. Activated carbon filters are one of my favorites for these extra filters, and those are made to get rid of odors and filter gasses, which is really cool.

With all that now said, I’m sure you can see the difference between an air purifier and a fan. And, if you can’t, then let me just say that all that air cleaning magic that I just went over is stuff that only an air purifier can do–simple fans only spread all those things around.

4 Key Differences Between Air Purifiers and Fans

Now, I know I’ve already gone over this a bit, but there’s more that I need to dig into here. So, here’s an entire section on the key differences between air purifiers and fans. (Don’t worry, I’ll speed through the things we’ve already gone through here!)

1. Air Purifiers Aren’t as Good at Cooling the Air.

Fans are usually a whole lot better at cooling the air in a room than an air purifier. That’s because that’s what fans are made for. Air purifiers exist to clean the air, not cool things down.

fawn pug covered by Burberry textile between plants

So, if you want cooler air in your home, then a fan is the way to go (or preferably an air conditioner in order to get it colder).

But, if you’d like cleaner air, then an air purifier is the only choice you should make. Fans just kick up dust and other stuff and shoot it all around the room. As such, a fan, on its own, will do more harm than good.

But why is this the case?

Fans, unlike air purifiers, are made to move large amounts of air as fast as possible. Their strong blades create strong breezes that you can feel all across the room. Air purifiers, on the other hand, have much weaker fans that are made to move all the air in a room, but they do is at a much slower rate.

Now, that isn’t to say that an air purifier won’t cool the air in a room, but it is to say that they are not the best tool for the job. Air conditioners, swamp coolers, and fans should be your go-to for cooler air in your home.

Oh, and before I go on, there are air purifiers out there that have built-in air conditioners, which is interesting. There aren’t a whole lot of those out there, but you can check out my article where I made a lineup of the best air purifier air conditioner combo units here.

And, if those aren’t your thing, then there are also air purifiers out there called “water-based air purifiers” and “water air revitalizers” and a few other iterations of that same name. Those units use water as their filter instead of a HEPA filter. If you know how swamp coolers work, then you know that these water air purifiers will cool the air more than a normal air purifier, but that comes at the cost of their ability to clean air very well. You can read up on them in this piece I wrote: What is a Water Based Air Purifier? | The Pros & Cons of Water Air Revitalizers.

Alright, I think that takes care of that, so onto the next key difference!

2. Air Purifiers Clean the Air, Fans Do Not.

This is a big one and it’s what makes or breaks the sale for some people.

As I’ve already said, fans can (and do) actually worsen air quality when they kick up particles and send them flying all around the room. That basically makes them and air purifiers exact opposites. The strength of a fan is its undoing when it comes to air quality. Sure, fans cool the air better than air purifiers, but that can be at the cost of dirtier air.

If you have allergies, asthma, or if you’re afraid of getting sick from someone in the same room as you, then a fan likely is not your best choice. Air purifiers are. Air purifiers lessen the spread of airborne illnesses and they remove allergens from the air, in addition to other irritants that might cause an asthma attack.

You can read up more on air purifiers with HEPA filters here. In that article I talk about why HEPA filters are important, how they work, and why they’re important in air purifiers.

Now, since I’ve already gone through most of this earlier on in this article, I’ll just restate that air purifiers clean the air and fans do not. Now, onto the next key difference!

3. Air Purifiers Remove Odors From the Air, Fans do Not.

This has a lot to do with the previous difference, since odors do play into air quality.

However, an air purifier’s ability to pull odors out of the air does warrant mention.

Air purifiers, unlike fans, are great at removing odors from the air. Sure, fans can help to make odors more bearable by spreading them out or shooting them out somewhere, but only an air purifier can remove those odors from the air altogether.

As I mentioned earlier, air purifiers can cleanse the air of odors because of their HEPA filters and activated carbon filters.

This is possible because odors take two forms, one is purely gas and the other is microscopic particles. The odors that are carried on in a gas form can be captured by an air purifier with an activated carbon filter. The microscopic particle odors can be captured with a HEPA filter.

Here’s a short list of a few of the odors that an air purifier with an activated carbon filter and HEPA filter can clean out of the air:

  1. Cooking Odors
  2. Wildfire Smoke
  3. Bathroom Odors
  4. Dirty Diaper Odors
  5. Pet Odors

And, again, that’s just a short list of a few of the things air purifiers can help with–there are a ton more!

Fans, unlike air purifiers, can’t get rid of any odors. They just move them around and potentially make them someone else’s problem. For a similar price, an air purifier can be a great option!

And, on that subject, here’s an article I wrote that might be of interest! Do I Need an Air Purifier in My Bathroom? | 6 Reasons Why You Should Get an Air Purifier for Your Bathroom

Now that that’s out of the way, here’s the final key difference that I’ll address today.

4. Air Purifiers Are Great to Run 24/7 Fans Might Not Be.

There is some controversy over this one, so I just want to say that I’m on the fence here myself. I see the merits of both arguments on what I’m about to say about a fan’s 24/7 use.

Now, the argument that people bring up about fans running 24/7 is that they can dry out the air in your house and that brings about issues and causes irritation to your skin, ears, eyes, and other things. They also say that fans can catch fire (because we see that happen all the time–not).

However, we all know people who can’t sleep without a fan going, for one reason or another. Maybe they get too hot when they sleep, maybe they need the white noise to drown out the other noises out there, or some other reason.

Now, while I think the whole catch fire argument is a lame cop-out, I will agree that dry air causes irritation. That’s the science. What I am less sure of is how a fan is supposed to get rid of humidity–all it’s doing is moving air around. It might be possible, but I’m not about to spend ten years of my life researching that.

However, with that being said there, fans can dry out your skin and the rest of you if they’re blowing directly on you for hours on end. This is especially evident in low-humidity environments, but a humidifier could easily take care of that. (See if you need a humidifier or a dehumidifier in this article.)

Okay, so, maybe I’m not that much on the fence, but I did have to mention the argument people who dislike 24/7 fan users bring up.

With that out of the way, let me talk about using air purifiers 24/7. They are supposed to be run all the time, so they’re made for that. Fans aren’t really meant for that, so that might be the basis of some of the aforementioned arguments.

On top of that, air purifiers can help you sleep (clean air helps people sleep better, there are quite a few studies on that. Check out this article for more on air purifiers in your bedroom). Yes, fans do help people sleep too, but it’s for different reasons that usually rely on preference, air purifiers help everyone.

Air purifiers, like fans, also create some white noise as they operate. Depending on your fan and air purifier one might be louder than the other. Air purifiers are usually quieter, but there are some incredibly quiet fans out there too. Conversely, there are louder air purifiers and louder fans too (and many in the middle), so you can decide which you like.

Now, I really could go on and on about how air purifiers help people sleep, hence why I wrote a few articles on it, but I’ll leave it there.

Should I Get an Air Purifier or a Fan?

At the end of the day, I can’t really tell you what you do or don’t need. Personally, I think everyone should get an air purifier, since clean air has so many benefits, but that isn’t to say that you “need” an air purifier right now if what you are looking for is a fan.

If you want to cool off your home’s air, then a fan is the obvious choice (or an air conditioner or maybe a water-based air purifier).

However, if cooling off the air in your home isn’t the main thing you’re thinking about and you want cleaner, healthier air, then an air purifier is the pick for you. If you’d like to get an air purifier, I’ve been using them and testing them for years, so I like to think I know what are the good ones and what aren’t. You can see my list of all-time favorites and recommendations here: Air Purifier Essentials Top Picks: Best HEPA Air Purifiers on the Market. Again, I actually have used and tested these, and I’m not just trying to sell you stuff that I haven’t ever touched, like a lot of bloggers. On top of that, most of the air purifiers on my list are incredibly affordable.

And, if you’ve read this far, then I’d like to add that the Levoit air purifier on my recommended list is my all-time favorite by far–and it’s one of the cheapest too, so be sure to check that one out!

With all that said, thank you for your time and for reading along with me today! Below I’ve listed some related articles that might be of interest to you.

Worried about the cost of an air purifier? Here’s a piece just for you! How Much Do Air Purifiers Cost? | The Price of Air Purifiers

Want to see if a water-based air purifier is the right pick for you? Check out this article How Well do Water-Based Air Purifiers Work?

Want a water-based air purifier? Here’s a piece comparing them to oil diffusers, which is another kind of machine that I enjoy. Water-Based Air Purifier Vs. Oil Diffuser Which is Better?

Finally, if air quality is a concern of yours, maybe it’s time you start thinking about something called radon. Radon is a toxic, radioactive gas that causes lung cancer. Here’s an article I wrote on how you can easily test your home’s air for radon: What is the Best Radon Test? A Look at the Top Three DIY Radon Tests Anyone Can Get and do at Home

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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