Can Air Conditioning Trigger Asthma Symptoms And Attacks?

Can Air Conditioning Trigger Asthma Symptoms And Attacks?

Air conditioning is a double-edged sword for people with asthma: You can use it to improve your indoor air quality and eliminate common asthma triggers. But, an AC with even minor problems or maintenance needs causes flare-ups and asthma attacks.

It’s a critical topic for the summer. It’s peak allergy season, with plenty of pollen everywhere. Even a summer shower can be a trigger for asthma attacks.

Related: Common Asthma Triggers From Mother Nature (And How To Avoid Them)

And, we keep our doors and windows shut all the time once the AC starts running. Without fresh air circulation, there is all sorts of buildup, especially dust and pollen, in the home.

As a result, indoor triggers are a massive contributor to asthma flare-ups and even death. But, there’s plenty you can do to make your home safer — starting with your cooling system in the summer.

We’ll explore the good and the bad of AC’s and asthma in this article. That includes what cooling features you can use to improve indoor air quality. And, what to watch out for — and how to fix it. 

Related: Breathe Smarter: New Asthma Treatment Technology [2022]

If you have questions or concerns about our home’s indoor air quality or any problems with your mini split, call HydroKleen208 at (208) 779-5596. We serve homes and businesses from Boise, ID to Cascade in Valley County. 

Air Conditioners And Asthma

Your air conditioner can help alleviate asthma symptoms. But only if it’s working properly. If it’s not, your AC makes things worse.


Along with keeping you cool, an air conditioner reduces the presence of significant asthma triggers.


When the AC’s running, air flows from each room through the return vent and into your HVAC system. The filter captures all the dust and dirt that comes in with it.

That means fewer dust particles in the air to trigger coughing fits, trouble breathing, or a full-on asthma attack. And, you can upgrade to a stronger filter that catches tiny contaminants, including pollen.

Humidity Control

Part of your AC’s job is to dehumidify your home or remove moisture from the air. Along with keeping you cool, it makes it easier to breathe.

Air with too much moisture affects the nerves in your lungs, which cause your airways to tighten. Keeping your home between 30 and 50 percent relative humidity reduces the chance of that happening.


The two features on your air conditioner that help manage asthma can also make it worse.

Dust And Dirty Filters

Eventually, the air filter in your HVAC system gets clogged with dirt. The result is less airflow throughout the house because air can’t make it past the dirty screen and into the system.

That means less cool, dry air in the house and more warm, humid air.

Next, excess dust comes loose from the filter and make its way back through the vents. All those tiny irritants are now circulating through your home again, where you can breathe them in.

Fortunately, there’s an easy fix: Change the filter every month when you’re running the heat or AC. And put a new one in every three months when the system’s off.


Mold is a bigger problem with mini splits than conventional central air. And, once again, humidity is a significant factor.

Mold triggers asthma symptoms in the form of an allergic reaction: When you breathe in spores floating through the air, your body perceives them as a threat. Along with other responses, your immune system causes your airways to constrict. 

Cooling and humidity control prevents mold spores from growing at home because they require someplace dark, damp, and warm. 

But, it’s dark and warm inside your AC unit. That’s also where moisture from the air condenses back into the liquid. It doesn’t take much for even a small malfunction to allow mold to begin thriving. 

Even just a dirty filter can cause this problem: Interrupting the airflow means more warmth and stagnant water inside your cooling system. 

Mini Splits Vs. Conventional ACs

A Ductless Mini Split Is A Great Heating And Cooling OptionEven though forced-air systems are more common, ductless systems are becoming more popular. That’s especially so here in Boise and up in Valley County. 

Mini splits are an excellent option for upgrading their century-old homes in Boise or converted vacation homes in Donnelley or McCall that never had ductwork. 

Even larger luxury houses in Caldwell and new suburban homes in Kuna benefit from the upgrade. Most new homes don’t have the best ductwork design, and some owners have bypassed that by going with a ductless system instead. 

But, with those benefits come a few indoor air quality concerns, especially for people with asthma. Fortunately, they’re easy to address. 


Unlike conventional central air, mini split filters are reusable. Instead of buying those cardboard-framed filters at the hardware store, you take out a plastic screen, clean it, and put it back in.

It’s a little more work, and as a result, people tend to put it off longer. That means more dust and dirt building up inside the air handler.

Meanwhile, ductless air handlers are excellent for airflow. Most have more than a dozen circulation patterns to spread the air — and dust — far and wide.


The big problem with mini splits is mold — and it’s more common than you’d imagine. Instead of one cooling unit for your home, each air handler dehumidifies from inside the room it’s treating.

So, you get a lot of moisture moving over the coils in each indoor unit. The result? That perfect dark, damp, and warm breeding ground.

What’s even worse is that the coil gets clogged very quickly. Even within a year, you may notice less airflow and maybe even stale air in some rooms. Here’s what’s happening inside the system:

A Ductless System Can Get Moldy If Not Taken Care Of

A clogged coil that can’t function properly. What makes the air stale or smelly is mold circulating from the unit.

Even for a professional HVAC tech, it’s difficult to take apart an air handler and clean it thoroughly. Instead, you need a separate deep cleaning.

Related: How Often Should A Mini Split Be Cleaned?

Mini Split Deep Cleaning

HydroKleen Global designed a mini split deep cleaning that eradicates all the dust, allergens, and microbial contaminants inside your mini split with one quick and easy visit. Now, HydroKleen208 brings that technology to the Treasure Valley. 

Related: Breathe Better, Stay Healthy, Keep Comfy: The HydroKleen Difference

Our customized equipment reaches every surface inside your air handler and heat pump without taking them apart. Our sprayers are calibrated to do the job without using so much pressure that they’ll break any delicate parts inside the units. 

And, our cleaning solution is 100-percent non-toxic and safe for the environment. 

And, the results speak for themselves. Here’s a photo where one of our techs cleaned the right side of the coil in an air handler. Compare that to the uncleaned portion:

You Can See How Dirty A Mini Split System Can Get

If you’ve had a mini split for more than a year, it’s time for a cleaning — especially if you’ve noticed any airflow or indoor air quality issues. 

One visit makes a big difference. You may even notice lower electric bills afterward because a clean system runs more efficiently than one that’s clogged and dirty. 

Related: What Does It Cost To Clean A Heat Pump?

Mini Split Cleaning In Cascade, ID

HydroKleen208 guarantees the most effective mini split cleaning for the ductless system in your Cascade, ID home or business. We bring more than a decade of dedicated research and development to Valley County and Boise Metro. Click below or call us at (208) 779-5596.