a guy holding his nose to protect him from air purifier smell

Why Does My Air Purifier Smell Bad

by Karl von Luckwald / January 16, 2024

Sometimes air purifiers emit unpleasant odors that leave us wondering, “Why does my air purifier smell bad?”

So if your air purifier is one of those, you’ve come to the right place.

In this article, you’ll learn about the causes and types of smells. Finally, you’ll know what to do and how to fix the issue. Let’s go.

WHY Does my air purifier smell bad?

Air purifiers may smell due to clogged filters or certain filtered substances. Odors range from a musty, wet dog, and plastic to sour, ozone, sweet, or burning plastic. Solve this by sun-drying filters, using the purifier to remove new smells, changing filters, or seeking professional help for serious issues. Regular cleaning prevents odors.

What Causes Bad Smells in Air Purifiers

Air purifiers clean the air by pulling it in and catching bad stuff like dust, smoke, and even tiny germs in special filters.

These filters are called HEPA and carbon filters. HEPA filters are extremely useful because they consist of fine fibers that grab onto even the smallest particles.

a clean white hepa filter next to a dirty hepa filter
A new HEPA filter next to a dirty HEPA filter

However, these HEPA filters can sometimes start to smell. Why? Because they catch so much stuff, they can get full and stinky over time. If they get too packed with things like dust, mold, or germs, or if they touch certain chemicals, they might start to give off bad smells.

These smells can be anything from the mustiness of mold, the yuckiness of too much dust, or even a strange smell from the materials of the purifier itself.

microscopic view of a hepa filter showing thousands of fibers
A HEPA filter under the microscope: The fibers can get damp in humid areas

Different Kinds of Air Purifier Smells

My Air Purifier Smells Musty

A musty smell often indicates mold or mildew growth, usually due to damp filters. It’s a common issue in humid environments or if the air purifier hasn’t been used regularly.

How to fix a musty air purifier smell

Remove the HEPA and carbon filters from your air purifier and leave them in the sun for a few hours to dry. This often removes musty smells. Then put them back and see if the smell is gone. If it’s still there, you might need new filters.

Why Does My Air Purifier Smell Like a Wet Dog

If your air purifier’s HEPA filter is damp and catches mold, it may emit a wet dog smell. This happens in humid environments and/or if you haven’t used your air purifier in a long time.

What to do Against wet dog smell

Put the HEPA filter from your air purifier in a sunny spot for a few hours. This helps dry it out. Once it’s dry, put it back in the purifier and see if it still smells like a wet dog. If the smell stays, it’s time to get a new filter.

My Air Purifier Emits Plastic Smell

New air purifiers sometimes emit a plastic smell. This is a common issue. and happens due to the off-gassing of new plastic components and typically dissipates after a few hours of usage

How to fix the plastic smell?

Keep your air purifier on for a few hours. Although the smell might be strong and unpleasant, it usually disappears after a while. If it doesn’t go away reach out to the vendor and let them know. They should be able to replace it for you.

Why Does My Air Purifier Smell Sour?

A sour smell can indicate bacterial growth within the purifier. This often occurs if the purifier traps high moisture content, creating a breeding ground for bacteria. Sour-smelling carbon filters are a sign of saturation.

What to do when the air purifier smells sour?

If your air purifier has a sour smell, figure out where it’s coming from. If it’s the HEPA filter, put it in the sun to dry and check if that gets rid of the smell. If the smell remains, you might need a new one. If the smell is from the activated carbon filter, it’s probably full and needs replacing.

Help, Why Does My Air Purifier Smell Like Ozone

Some air purifiers that use ionizers can produce an ozone smell, reminiscent of a faint bleach-like odor. Ozone is a byproduct of ionization and, in large quantities, can be harmful to health.

How to fix air purifiers that smell like ozone?

Find out if you can disable the ionizer function of your air purifier. Since some ionizers emit ozone this should solve the issue. If the ozone smell persists contact your vendor to get further instructions.

My Air Purifier Smells Sweet

Sometimes, new air purifiers smell sweet. Don’t worry, it’s normal. Also, if your purifier is filtering things like certain smoke or aerosol sprays from the air, it might smell sweet.

What to do against sweet smell?

If it’s new: Just let it run for a few hours. The sweet smell will usually go away.

If it’s not new: Try putting the HEPA filter in the sun for a bit. If the sweet smell is still there after, call the place you bought it from for help.

My Air Purifier Emits a Burning Plastic Smell

A burning smell is a serious concern. It can indicate an electrical problem or overheating within the air purifier.

How to fix the burning smell?

If you notice this smell, turn off your device immediately and consult a professional. Using this air purifier may not be safe.

Maintaining Air Purifiers

Maintaining your air purifier is crucial for its efficiency and longevity:

Regularly Change Filters: Follow the manufacturer’s recommendations for filter change.

Keep the Purifier Dry: Avoid operating in overly humid conditions unless it’s designed for such environments.

Regular Cleaning: Regularly clean the exterior and non-electronic parts with a dry cloth. Always unplug the air purifier while doing so. Of note: washing HEPA filters with water will harm the fibers and is not recommended.

Proper Placement: Ensure your air purifier is placed in an area with good airflow and away from direct moisture sources.

Bottom Line

To keep your air purifier smelling fresh, regularly change the filters, keep it dry, clean it properly, and place it in a well-ventilated area. Address specific smells like musty, wet dog, or burning plastic with targeted solutions like drying filters in the sun or seeking professional help.

Karl von Luckwald

Karl von Luckwald

Since moving to Thailand in 2019, Karl noticed the lack of scientific integrity in air purifier and water filter reviews. In response, he founded WE DO AIR to champion unbiased, science-based evaluations and empower consumers to make better-informed decisions.

Have a question? Add us on Line
Click to Chat With Us!