Air purifiers are life savers as they help us get rid of the annoyingly dusty air and the persisting odor from our homes. With an air purifier, you can make your place liveable again. But if air purifiers are supposed to clean the air, why does my air purifier smell sour?
And it seems that the carbon filter is the source of this annoying and worrying smell. The most likely reason is the irregular maintenance of the filters(Yes, I am the culprit). However, there are several possible reasons behind that smell.
In this article, we’ll be trying to pinpoint the exact component responsible for the problem. So if you’re suffering from this, give it a read.
6 Common Smells That Come from Air Purifiers
Before we get into the solution to your problem, we want you to be very clear about the smell you’re receiving. It could be any of the 6 common odors for which air purifiers are known. Here are the familiar smells other than sourness:
Take a moment and investigate if what you’re experiencing is listed above. If yes, the solution is different, or you may not even need to fix anything at all.
However, if it’s the sourness you smell, we’ve got you.
The Reason Why Your Air Purifier Smells Sour
Take any modern filter, and you’ll find a multi-layer filtration system in place. There will at least be a HEPA filter in it and also an activated carbon filter to tackle the smelly situations.
Sometimes these air purifiers will give a sour smell, and the culprit is these filters. After a long period of usage, the sour smell will start to come out from the device and become noticeable.
Which Filter Is to Blame; HEPA or Carbon?
Right away, most of us would point fingers at the HEPA. It’s not unreasonable to think that the HEPA filter is causing the problem since it’s the job of the carbon filter to remove the smell. It can’t possibly start producing a smell, can it?
Well, be prepared to be shocked like I was when I first found it out that the culprit is the carbon filter.
Most of the time, if you take out the HEPA filter, it won’t smell of anything. And other times, you’ll only get a dusty smell from it.
On the other hand, the activated carbon filter in your purifier has been busy collecting all the smelly particles. And at one point, it won’t work at all but instead produce a sour smell after 6 months of continuous use.
And nothing to worry about as it is expected from it.
Through several tests, it’s been found that a high concentration of acetic acid is found on the surface of the filter. And acetic acid is known for its sour smell. Another probable cause is propionic acid, but the concentration is too low for it to be blamed.
How Does the Carbon Filter Produce Sour Smell?
The carbon filter has a surface full of chemical elements that have oxygen in it, such as carboxyl and lactone groups. For those uninitiated in the ways of chemistry, acids like acetic acid and formic acid are formed from these groups. And they all have oxygen molecules in them.
These functional groups can easily fall from the filter and mix with oxygen in a humid condition to create acetic acid. And this is the reason why your air purifier smells sour.
The surface of the carbon filter, i.e., the carbon cloth, has many volatile organic compounds retained from the air. It also receives PM2.5 particles and water. Such condition is extremely conducive to acid production, i.e., sour smell production.
How to Prevent Your Air Purifier from Producing Sour Smell
If your air purifier has an activated carbon filter, and you haven’t replaced it after a few months of continuous use, you’ll eventually smell sourness in the air. You will also experience sourness in the air if you don’t maintain good airflow for gases like formaldehyde to exit the house.
We have explained why and how it happens. Now you’ll know what to do so that it doesn’t happen to you.
- Replace your carbon filter after 3-4 months if you use it daily for 24 hours
- Wash it every month to keep its surface clean
- Maintain good airflow in the house to prevent humid conditions that help produce the sour smell
So, why does my air purifier smell sour? It’s because the filter is giving the signal to replace it as soon as possible. The filter either accumulated too many gas molecules and smell particles, or there is not good airflow in the house. What’s the solution? It’s simple; replace or wash the filter.
Last Updated on October 30, 2022