Help! My mini-split air conditioner is smelling weird

Help! My mini-split air conditioner is smelling weird

It is the middle of summer and you have just turned on your mini-split air conditioner for the first time this season. But as soon as it starts to blow cool air, you notice that there's a strange smell coming from the unit. What could be causing it? Is my old AC unit about to die? Keep reading because we are going to go through some reasons why your AC might start smelling weird and what you can do about it!

1. First, what is a mini-split air conditioner and what does it do

If you live in a warmer region than most, the idea of installing an air conditioner may be appealing. If so, there are a few things to consider before making your purchase! A mini-split air conditioner is one solution that offers many benefits for homeowners. Mini-split systems offer both cooling and heating capabilities while also being quieter and more efficient than traditional central AC units.

Additionally, a mini-split system is designed to fit into small spaces within your home. This means that you can install them in rooms where they are not only effective but also unobtrusive! Once again, this makes installation easy and keeps the unit from taking up any unnecessary space inside of your house.

2. What can cause the smell from my mini-split air conditioner

There are many things that could contribute to this foul odor, but below are some of the most common reasons why you might have an unpleasant scent coming from your AC system.

Dirty Filters Smell


A dirty filter should be the first thing you check if you experience any kind of odor or contamination in your home. The easiest way to clean this out is with a vacuum cleaner and then use lukewarm water mixed with dish soap and scrub away any dirt or debris that has collected on top of it.



Air Condenser Making it Smell

Condenser Airflow

There may be something blocking airflow into the condenser. This can happen if leaves, branches or other debris get sucked into the outdoor unit and then block it from pulling in cool air.




Pet Furr Making a Smelly AC


If you have pets that shed a lot of hair inside your home like dogs and cats, this could also be another reason why there is an unpleasant odor coming out of your AC system. The dust particles created by these fur babies can settle on the coils, not only blocking air flow but also providing a breeding ground for bacteria and allergens.


Mold & Mildew Making Your AC Smell

Mold and Mildew

Mold is the most common reason why your mini-split AC could smell weird. This often occurs as a result of excess water in an area or if there has been too much humidity over time that has created the perfect environment for mold to grow.  

Another reason why mold and mildew grow is because of improperly operating your mini-split system.  Mini-splits are designed as a ‘Set it and forget it’ appliance.  This means that once you set the temperature you want you should leave the mini-split alone and not turn it on and off like you would a fan.  

3. How to fix the problem of a smelly AC unit

The air coming out of my mini-split AC smells weird now what?

First, you should unplug your unit and then clean the interior coils of any dust or debris that may be there.

Second, many people don't realize this but dirty filters are often the culprit behind small problems like a smelly air conditioning unit so we recommend checking them and washing them.

Next, check for leaks.  If you spot a leak, have a professional take care of this immediately.  Only an HVAC professional should conduct major repairs on your mini-split AC system.   

Lastly, one major and common cause for a smell is mold inside the unit. Condensation from using the AC and not allowing it to dry off can encourage mold and mildew growth in places you can’t reach with typical cleaning. We recommend using our PureAC disinfecting device which allows you to disinfect your AC in just 30 minutes with the simple push of a button. The disinfection process used will remove this funky smell.

4. The benefits of having an energy efficient AC system in your home

Let's not forget about the benefits of having a well-functioning AC system in your home. Besides being able to enjoy cool air during hot summer days, it also helps you save on energy bills by keeping your house at a more comfortable temperature and lowering the thermostat accordingly. This optimized climate  can even help reduce our carbon footprint!

5. Why you should get professional help for any AC repair needs 

If you think your AC system needs repair, we recommend contacting a professional. They have the expertise and experience to diagnose the problem quickly so that it doesn't worsen. Plus, they will most likely be able to provide a more accurate quote for repairs for your valuable investment. They can quickly see if there are other areas of your mini-split air conditioning system that may need some maintenance.  In the end this will save you money with efficiency costs.

6. Tips on how to keep your mini-split running smoothly all year long

  • Check and clean the filters on your mini-split system every two weeks.
  • Have an HVAC professional clean the coils and blower wheel annually.
  • Once you set the temperature, leave the system on.  Turning your system on and off will create conditions that exasperate mold and mildew growth.
  • Lower your thermostat by one degree to keep cool air from escaping through cracks, leaks and drafts. It can even help reduce our carbon footprint!
  • Keep windows closed when indoors to maintain relative humidity levels that are optimal for AC performance.
  • Use a disinfecting device regularly, approximately every 2 weeks to inhibit mold and mildew growth along with making sure the air blowing out is clean, pure air.

We know that with the hot summer months, it will be important for everyone to take care of their air conditioner so they can enjoy a cool home even when outside temperatures rise. If after reading this article all those tasks sound like too much hassle for now but you still want some peace of mind that your AC isn't going to make your home smell terrible again anytime soon? Fortunately we have a solution! We recommend using our PureAC disinfecting device as part of a regular plan for your ductless mini-split system. It will help keep bacteria at bay and make sure everything stays fresh smelling year round!

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