If you've never cracked open the plastic cover of your split system to check the filters, now could be the perfect time.
After south-east Queensland's humid summer there's a chance your air conditioner could be harbouring dust, mould, and other particles harmful to your health.
Professor Lidia Morawska works at Queensland University of Technology's (QUT) School of Earth and Atmospheric Sciences and is the director of the International Laboratory for Air Quality and Health.
She says running a dirty or mouldy air conditioner can give you a blocked nose, cough and other cold-like symptoms in mild cases, or shortness of breath and fever in more severe circumstances.
"If you have lots of humidity and dampness in homes it is possible for fungi to establish itself in the air conditioner," she says.
"When it's running the spores are emitted into the air."
Professor Morawska says breathing in mould spores could also exacerbate allergic reactions and make people more susceptible to respiratory infections.
Start with a filter check
Chris Barnes from consumer watchdog CHOICE says cleaning your filters takes minutes to do, but is often overlooked.
"The filters on the indoor unit of your split system air conditioner really need to be taken out a couple of times a year at least," he told ABC Radio Brisbane.
If you haven't checked the filters in a while — or ever — he says the best way to remove heavy grime is by gently washing them in some warm water and a mild detergent.
Once they're clean and dry, your lungs aren't the only thing that will benefit.
A more efficient air conditioner means lower power bills.
"If it has really clogged filters it's going to struggle and use more energy than it should," Mr Barnes says.
Mr Barnes says running an air conditioner frequently during humid weather can also allow mould to thrive on the condensing coils.
"These are the pipes that the refrigerant gas runs through, which is the bit which does the actual heating or cooling of the air.
"They're condensing a lot of moisture out, and some of that moisture will stay on those coils and build up with mould."
To combat this, try to run your air conditioner's "dry out" mode if it has one.
Mr Barnes says this will help clear up any moisture on the condensing coils before you switch it off.
When should you consider a more serious clean?
If you can see mould growing on your air conditioner, a professional clean could be worthwhile, Chris Barnes says.
If you're tight on cash and would prefer to do it yourself, home kits are available for around $100.
"You'd want to be pretty confident and pretty handy to do those but it's entirely doable," Mr Barnes says.
"If you're not sure, it's probably better to get a professional in to do the full clean."
It's always a good idea to dig out the product manual and instructions for other tips on maintaining your air conditioner and keeping it clean.
If you can't find it, or threw it out after the install was done, Mr Barnes says they're usually available online through the manufacturer.
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