Is it possible that your air conditioner is actually making your home unhealthy? We love our air conditioner systems because they make our spaces cool & crisp in summer and nice & toasty when the mercury drops. But it’s just that if it’s been a while since your system was serviced, a build-up of grime and organic matter might have made your air conditioner the perfect place for mould and mildew to grow and thrive. And then, every time you turn it on, that air conditioner mould efficiently distributes even more harmful spores to every corner of your home, triggering allergies, worsening respiratory problems and generally making you sicker.

Are you failing to spot the signs of mould in air conditioner units? Before it has a chance to damage the components, smash its efficiency and hurt your family’s health, let’s look at the signs you need to look for.

What Causes Mould in Air Conditioning Systems?

Mould growth is a common issue in air conditioning units and ductwork. The moist, enclosed environment inside air conditioning systems provides ideal conditions for mould to develop and spread. A few key factors can cause mould infestation inside your home’s air conditioning unit and ducts.

Poor airflow and incomplete drying of condensation inside the air conditioning unit can allow moisture to accumulate, promoting mould growth, especially on the coils and drain pans. Clogged air filters also restrict proper airflow, leading to excess moisture enabling mould colonies to thrive inside the unit and air conditioning ducts. Leaky ductwork allows hot, humid outside air to enter the system, creating damp conditions and moulds. A lack of routine maintenance, like changing filters and cleaning ducts regularly, can worsen moisture issues and mould infestation over time. Even small leaks or drips from drainage pipes or coils can wet insulation and lead to mould inside air conditioning ducts.


Do You Have Mould In Your Air Con?

1. Does your air conditioner smell musty?

When it’s working well, your air conditioner should produce perfectly conditioned air that is completely odourless. So if you’re detecting something mildly musty when you turn your unit on, you’ve probably got to the problem before it’s become really bad – perhaps in the first 24 hours or so of an outbreak. But if that stale, damp smell is getting pungent, that’s when the mould spores are at their most allergenic, pathogenic and toxigenic.

2. Can you see the mould?

However, the clearest of the mould in aircon signs is quite apparent – because you can see it with your own eyes! We’re all familiar with what it looks like, even though we can sometimes dismiss it as nothing particularly problematic. But it’s time to take action if you see those characteristic dark, green or even white mould specks or ‘fuzz’. Straight away.

3. Do you feel unwell?

If you’re prone to allergies, or the infestation of mould in air conditioner systems has established itself, you might find yourself feeling quite unwell. The symptoms might also be mild, but that doesn’t mean the problem won’t worsen over time – particularly as air conditioners are the most efficient way to spread those spores around every corner of your home.

When you breathe in mould spores, the allergy-like symptoms include:

  • Congestion
  • Itchy/watery eyes
  • Runny nose
  • Coughing
  • Wheezing
  • Sore throat
  • Irritated skin/rash
  • Irritated lungs
  • Headache.

Don’t forget, these cold/flu-like symptoms can actually lead to much more severe illnesses – like pneumonia. It’s therefore crucial not only that you get the mould in air conditioner units sorted out quickly but also seek medical advice.

Preventing Mould In Your Air Conditioning System

The humid conditions in Queensland can be ripe for mould growth. You should maintain regular air conditioner maintenance and cleaning, preferably annually, done by a local air conditioning specialist. Depending on which air conditioner you have, periodically running it on a higher temperature with the “dry” setting can help prevent mould growth since this uses a built-in dehumidifier to extract the moisture in your home.

How To Remove Mould From Your Air Conditioning Unit


Have you detected air conditioner mould? Before we talk about fast & efficient air conditioner mould removal, double-check you have a problem by inspecting the a/c ducts and interior and exterior units. When doing this, wear gloves and, if possible, a mask to minimise the risk of inhaling the mould spores, particularly if you try to clean the filters and other air conditioner components with soapy water.

Unfortunately, mould is particularly good at hiding out of sight and out of reach. That makes removing it entirely from your air conditioner system complicated without understanding the complete anatomy of your unit and how to access, disassemble and reassemble it afterwards. Also, remember that trying to do this without being a licensed and trained HVAC specialist could be dangerous and breach various regulations – not to mention risk your warranties and insurance.

Need A Professional To Maintain Your Air Con?

To knock mould in aircon systems on the head, call our local electricians near you. Fully licensed, highly experienced, and always offering our lifetime workmanship guarantee, we know our way around almost every type and model of air conditioner fitted all over Brisbane, the Gold Coast and beyond. Say goodbye to air conditioner mould by calling Your Electrical Expert today.

Air Con Mould FAQs

How do I know if I have mould in my air conditioner?

Signs of mould growth in your HVAC system include a musty or damp smell when turning on your air conditioner, visible mould growth around the vents or air conditioning unit, and allergy-like symptoms that worsen when the AC runs, like itchy eyes, runny nose, and coughing. A professional air conditioning technician can thoroughly inspect your system for mould issues.

Why does mould grow in air conditioning units?

Mould thrives in the enclosed, humid environment inside air ducts and AC units. Factors like restricted airflow, clogged filters, condensation build-up, and leaks allow moisture to accumulate, creating prime conditions for mould infestation in the air conditioning ducts and system.

How can I prevent AC mould growth?

Routine maintenance from an HVAC specialist is critical to preventing mould in your air conditioner. This includes changing air filters regularly, properly draining condensation, sealing ductwork, ensuring adequate airflow, and periodic deep cleaning or disinfecting of the ducts and AC unit. Using mould inhibitors can also help suppress mould growth.

How is mould cleaned from an air conditioning system?

For any visible mould inside your air conditioner unit or air ducts, contact a professional air conditioning technician for a thorough deep clean. They have the expertise to fully disassemble, clean, and disinfect all HVAC system components to eliminate mould and prevent its return. Attempting to DIY clean AC mould is difficult and risks spreading spores.

When should I call a professional to address AC mould?

At the first signs of mould, like musty smells or allergy symptoms, when running your AC, contact an air conditioning specialist to inspect and clean your system if needed. Left unchecked, mould can damage your AC unit over time and pose health risks. Only a trained HVAC technician has safe, effective mould removal and prevention skills.