Why your Air Purifier is not Removing Odors (+ Fixes)

Your air purifier does not remove odors and you don’t know why? In this article, we’re going to check all the possible reasons and how to fix them.

Having clean and fresh air is important for your well-being. And air purifiers are supposed to remove odors. Or are they?

( There will be a surprising answer to this question – not all air purifiers can remove odors ) 

If you stick out until the end of this article, you’ll know exactly why your air purifier does not remove bad smells.

We’ll have a look at different types of air purifiers and whether they can remove odors.

Don’t worry if you find out your air purifier doesn’t remove odors! At the end of this post, I recommend you a good air purifier that definitely removes odors.

Quick answer: Your air purifier does not remove odors, because it lacks an activated carbon filter. If it has an activated carbon filter, make sure to run your air purifier long enough (8 hours). Also, replace filters. And remove the source of the smell.

Before we take the deep dive, let’s first check the most fundamental question:

Is your air purifier even capable of removing odors?

This question might seem counterintuitive. After all, isn’t that what air purifiers are made for?

To cleanse the air?

However, not all air purifiers are created equal, and some are better equipped to handle odors than others. Let’s take a closer look at the different types of air purifiers and whether they are able to remove bad smells.

HEPA Filter Air Purifiers

HEPA (High-Efficiency Particulate Air) filters are well-known for their ability to capture microscopic particles, including allergens like dust, pollen, and pet dander.

However, when it comes to odors, pure HEPA filters alone are not very effective.

They’re designed to filter particles from 0.1 microns and larger. Some HEPA filters can even filter smaller particles.

But gases (which create odors) are a whole different size class. Gases are tiny molecules. They are just a thousandth of the size of the smallest particle, a HEPA filter can reliably filter.

These gases can easily slip through HEPA filters due to their small size. For odor removal, an air purifier with an activated carbon filter would be more effective.

Please note: If you bought an air purifier with a HEPA filter, it might contain a layer of an activated carbon filter. In this case, it CAN remove odors! (We will see how you can check this later)

Activated Carbon Filters

Activated carbon filters are, just like HEPA filters, airflow-based. So, air passes through them.

Activated carbon has an incredibly high surface area of up to 3,000m² per gram, which makes these filters “sticky” for gas molecules.

Here are a few examples of smelly gases activated carbon can removes:

Activated carbon filters remove odors better than any other filter type.


Ionizers are a special kind of air purifier, which release charged particles (ions) into the air.

The charge causes these particles to clump together with other particles in the air and causes them to fall down.

Ionizers don’t remove odors. Even though they can ionize molecules in the air, this doesn’t mean these molecules lose their bad smell.

UV Light Purifiers

UV purifiers use ultraviolet light to kill microorganisms like bacteria and viruses. While this is highly effective for sterilization, it doesn’t have any direct effect on odors since UV light doesn’t interact with gas molecules.

( At least not in a way that removes them )

Ozone Generators

Ozone generators produce ozone, a gas that can neutralize odors.

If you use an ozone generator at home, it should be able to reduce odors. However, it’s very unhealthy for humans.

“There is evidence to show that at concentrations that do not exceed public health standards, ozone is not effective at removing many odor-causing chemicals.”

United States Environmental Protection Agency

Likely, this means that at concentrations that are higher than public health standards, ozone does remove odors.

( Of course, an environmental protection agency wants you to reduce ozone emissions )

However, they are generally not recommended for home use because ozone can be harmful to health, especially in high concentrations.

PECO / PCO Filters

Photo Electrochemical Oxidation (PECO) and Photocatalytic Oxidation (PCO) Filters filters use light to trigger a chemical reaction that breaks down particles, including VOCs (volatile organic compounds) which are often the source of odors.

PECO filters are effective at removing odors.

So, is your air purifier capable of removing odors? It all depends on the filter and air purifier type:

Air Purifier Filter TypeCan it remove odors?
HEPA FilterNo, except it’s a combined HEPA + carbon filter
Activated Carbon FilterYes
UV Light PurifiersNo
Ozone GeneratorsYes, but not recommended due to health risks
PECO/PCO FiltersYes
odor removal effectiveness of different air purifier filters
Odor removal effectiveness of different air purifier filters: Activated carbon and PECO filters are best. Ozone generators work, but can be unhealthy (hence the warning sign).

Which air purifier filter do you need for odor removal?

The best air purifier filter type for removing odor is activated carbon.

Since most likely you run an air purifier with a built-in HEPA filter, I recommend replacing the HEPA-only filter with a HEPA + activated carbon combined filter.

For example, for the Levoit Core 300 air purifier, I recommend getting this HEPA + activated carbon filter (click here to view it on amazon).

But pay attention:

Many air purifiers already have combined HEPA + activated carbon filters built-in by default.

Here are some air purifier brands that are equipped with combined filters:

  • Levoit
  • Germ Guardian
  • Winix
  • Blueair
  • ( and many more … )

If you don’t know whether your air purifier has a combined HEPA + activated carbon filter, II recommend looking for original replacement filters online.

Usually, you’ll find the word “carbon” on the sales page.

Alternatively, you can take out your air purifier’s filter and check for a black layer. Here’s what my filter with activated carbon looks like:

air purifier hepa filter levoit core
The inner filtering layer contains hundreds of black pieces. That’s the activated carbon.

Other common reasons for your air purifier not removing odor

In the previous section, we made sure you have an air purifier that is capable of removing odor, to begin with.

But there are a couple more potential causes for your air purifier not removing odor. Let’s have a look.

Too small air purifier

You air purifier may simply be too small for your space. If you run your air purifier in a large room, such as a living room, it can make sense to get a dedicated, more powerful air purifier for that room.

For living rooms, get at least the Levoit Core 400 (click here to view it on amazon) or larger.

This air purifier is powerful and it has a built-in combined HEPA and activated carbon filter.

So, it will remove both smells and particles.

Worn-out / clogged filters

You have to replace your air purifier filters every 6 months! After 6 months HEPA filter particle reduction efficiency reduces to just 50%.

So, after 6 months of usage, a filter can only collect half of the particles a new filter could collect.

For removing smells, make sure you get a HEPA + activated carbon filter! (Preferably original)

Air purifier running not long enough

Air purifiers need time to absorb odors. I’ve seen some air purifier companies advertise something along the lines of “this air purifier filters your room’s air 3 times per hour”.

That is obviously nonsense.

An air purifier pulls in that volume of air per hour, yes. But that doesn’t mean that it pulls in only “dirty” air. To a large portion, it filters air it already cleaned.

Meanwhile, some stale air zones in your room are hard to reach for your air purifier. And possibly that’s where the odors reside.

It takes time for your air purifier to really filter all the air in your room. So, run it longer!

I suggest 8 hours per day.

( Air purifier running cost is very low, so don’t worry about it )

Air purifier does not clean the source of the smell

Air purifiers with built-in activated carbon filters remove smelly gases from the air in your room.

However, if you don’t remove the source of the odor, no air purifier can keep up with it.

For example, rotten food, litter, etc.

All these things need to go out of your house and into the trash!

How to improve air purifier odor removal effectiveness

You now already know which air purifiers (and which filters) to use to get rid of odors. Also, you know the things not to do.

Here’s a quick action list based on what we already discussed:

  • Use a strong, well-sized air purifier (with a built-in HEPA + activated carbon filter)
  • Replace filters (this can make a huge difference)
  • Run your air purifier for longer times
  • Clean the sources of odors

If you can tick the boxes of all 4 checkpoints, you should be able to get rid of most odors in your home.

Before we have a look at a couple more key-strategies to remove smells in your home, here’s one important learning:

Air purifiers never remove all smells

Keep in mind that an air purifier never removes all smells. Some air purifiers have better filters and more power than others.

But no air purifier is perfect.

“As a purifier for smoke and odor, this is actually a pretty good one though. When I cook and this turns on, my house smells less – although it doesn’t completely eliminate the smell. In fact, neither the Coway nor the Levoit was able to completely eliminate smells (but that was not my concern at all).”

Zenzinin on a Levoit Core 400 review

Based on this, let’s postulate the following:

“For ideal smell removal, an air purification needs to run in a clean and vented home” Daniel (me) from heatertips.com

Clean your home

Air in a clean home is easier to purify than air in a cluttered and dusty home.

Clean your home regularly. Put order into things. Vacuum the floor.

Occasionally wipe the floor.

The less clutter and dust there is in your living space, the smaller the surface area for bad odors to stick to.

A cluttered and dirty room, (ironically) similar to a charcoal filter, has a large surface area that attracts smells.

Vent your home

Also, vent your home. Especially if the odor originates from inside your home (from cooking, or whatever), venting is more effective than purifying.

The airstream from venting just carries the air outside.

Although, I understand if your situation is exceptional. For example, I once lived in a small one-room apartment with one window. Venting was pointless since you can’t create an airstream with just one window.

But if venting is possible for you, do it!

You can even keep your air purifier running with a window open.

The air entering from the window not only carries bad odors outdoors, it also redistributes gases and particles and makes them easier to pick up for your air purifier.

Recommended air purifier to remove odors

My favorite odor-removing air purifiers are the Levoit Core series air purifiers. Personally, I use the Levoit Core 300 (see my review).

But I live in a moderately sized home. I usually run it in my 120 sq. ft. room. My apartment is roughly 800 sq. ft.

If your living space is a similar size, I can highly recommend the Core 300!

For larger spaces, I recommend getting the Levoit Core 400 (click here to view it on amazon) or the Core 600.

You can choose the size (Core 300, 400, or 600) on the purchase page!

All Levoit Core air purifiers come with a combined HEPA and activated charcoal filter.

So, they are able to remove odors from your room.

Frequently asked questions about air purifier odor removal: Answered!

Q: Can an air purifier completely eliminate pet odors?

A: While an air purifier can significantly reduce pet odors by capturing pet dander and other airborne particles, it may not completely eliminate them. It’s also important to regularly clean and maintain pet areas to effectively control odors.

Q: Are air purifiers effective against cigarette smoke?

A: Yes, air purifiers with activated carbon filters can be effective at reducing the smell of cigarette smoke. However, for complete smoke odor removal, source control and regular home cleaning are also necessary.

Q: How long does it take for an air purifier to remove odors?

A: The length of time it takes an air purifier to remove odors can vary based on the size of the room, the capacity of the air purifier, and the intensity of the odor. In general, you may notice an improvement in air quality within a few hours, but it could take longer for stronger odors.


Your air purifier needs an activated carbon filter to remove most odors. Additionally, make sure to use an air purifier powerful enough for your living space.

And, of course, replace filters regularly!