Don’t Ignore That Musty Smell: Why Your AC Needs a Professional Clean

Are you ignoring that musty smell coming from your AC? It’s easy to dismiss it as a minor inconvenience, but did you know it could indicate a bigger problem lurking within your air conditioning system?

A musty, stale or mouldy smell from your air conditioner isn’t a quirk of the system — it’s a sign that mould, bacteria or organic buildup has established inside the unit. In Queensland’s humid climate, this is one of the most common AC complaints, and it won’t resolve itself.

Regular cleaning and maintenance of your AC unit are essential for ensuring optimal performance and keeping the air in your home healthy.

This article will explore why neglecting professional air conditioner cleaning can lead to costly repairs and health hazards. So sit back, grab a cold drink, and learn more about the importance of maintaining clean air conditioning systems!

What’s Actually Causing the Smell?

The inside of an air conditioning unit is a near-perfect environment for mould and bacteria growth: dark, warm, with regular condensation and a constant supply of organic particles (dust, skin cells, pollen) being drawn in through the return air.

• Mould on the evaporator coil is the most common source. When warm, humid air passes over the cold coil, moisture condenses on the coil’s surface — and if the drain tray doesn’t clear it fast enough, or if the coil isn’t cleaned regularly, mould colonises the condensate and begins spreading through the unit. Every time the fan runs, it circulates mould spores through the room.
• Bacteria in the drain tray produces a distinctly sour or sewage-like smell. Standing water in a blocked or partially blocked drain tray is a breeding ground for bacterial growth that the fan then distributes through the room.
• Dust and debris on the blower fan creates a burning or stale smell — particularly when the unit is first turned on after being off for a period. The fan blades accumulate a coating of greasy dust that becomes musty when airflow disturbs it.
• Dead insects or animals in the unit or ducting produce an unmistakeable smell that comes and goes depending on airflow. More common in ducted systems and ceiling cassettes than in wall-mounted split systems.

A professional split system AC clean — or equivalent service for ducted or cassette systems — addresses the problem at the source rather than masking it.

Why Queensland Properties Are More Susceptible

Queensland’s subtropical and tropical climate means air conditioning runs for significantly longer periods than in cooler states. In Brisbane and the Gold Coast, systems run for 6+ months a year; in Far North Queensland, year-round. Longer run time means more condensation cycles, faster accumulation of organic material, and faster mould establishment.

Coastal properties face additional pressure: salt particles carried in ocean air promote corrosion of coil surfaces, creating micro-pits where mould establishes more easily.

Holiday let properties and investment homes often have systems that run heavily during peak season and then sit idle — the combination of established mould and a dormant unit is what produces the powerful smell guests notice immediately on arrival.

Benefits of Professional Air Con Cleaning

Your air conditioner works hard to keep your home cool and comfortable during the hot summer. However, your AC can develop a musty smell if it isn’t properly cleaned. This is caused by mould and mildew growth within the unit, which can indicate that your AC needs professional cleaning.

There are many benefits of professional AC cleaning, including:

1. Improved Air Quality – If your AC is full of mould and mildew, it can cause allergic reactions and respiratory problems. Professional air con cleaning will remove these contaminants from your AC unit, improve the air quality in your home, and make it safer for everyone to breathe.
2. Increased Efficiency – A dirty AC unit must work harder to cool your home, which uses more energy and raises utility bills. Cleaning your AC will help it run more efficiently, saving you money on your monthly energy bills.
3. Extended Unit Life – An unclean AC unit is more likely to break down or need repairs than a clean one. Regular professional cleanings will help extend the life of your AC unit, so you don’t have to replace it as often.
4. Odour & Smell Elimination – Musty smells aren’t just caused by mould and mildew; they can also be caused by dirt and dust buildup within the unit. A professional cleaning will remove all of these odours from your AC unit so you can enjoy your home’s fresh, clean air.

What Does a Professional Air Conditioner Cleaning Include?

Your air conditioner works hard to keep your home cool and comfortable all summer. But as it runs, it collects dust, dirt, and other debris. Over time, this can cause your AC to smell musty.

A professional AC cleaning should include:

• Pre-check and test the air conditioner temperature and fans to ensure the unit works.
• Check the surroundings and protect them with a waterproof tarp.
• Remove filters and unit cover and take them outside to clean and sanitise.
• Spray treatment foam kills mould and bacteria and loosens dirt from coils, drains, fans, fan housing and filters. Leave it for 5-10 min to activate.
• Using a pressure hose, fully wash the treatment out with clean water.
• Flush and check the drain to ensure there are no possible leaks.
• Check fan blades and covers for corrosion and/or grime.
• Spray the unit with sanitiser and antifungal products to prevent mould and bacteria from regrowing.
• Reassemble all components, dry excess moisture on or around the aircon unit and test airflow again. Clean and tidy, leaving the area as we found it.
• Provide a completed next service sticker with recommendations for future aircon high performance.

How Often Should You Get an AC Clean?

Like most people, you probably don’t think about your air conditioner until it starts making strange noises or blowing warm air. But just because you can’t see or hear your AC doesn’t mean it doesn’t need regular maintenance. So one of the most important things you can do for your AC is to have it cleaned by a professional regularly.

So how often should you get an AC cleaned? The answer depends on a few factors, including the type of air conditioner you have, your climate, and how often you use your AC.

Annual cleaning is the minimum for most Queensland properties. Systems that run daily through summer — or holiday let properties that run continuously through peak periods — benefit from cleaning every 6 months. And if you have allergies or asthma, you may want to get an AC cleaned more frequently since dirty filters can exacerbate these conditions.

In general, it’s best to schedule an AC clean when you know your unit will be getting heavy use. 

DIY Tips to Keep Your AC Smelling Fresh

When it comes to keeping your AC smelling fresh, there are a few DIY tips you can follow to help:

1. Make sure you regularly change your AC filter. A clean filter will help to remove any bad smells that may be coming from your AC unit.
2. Keep your AC unit clean by regularly wiping it down with a damp cloth. This will help to remove any dirt or dust that could be causing the musty smell.
3. Consider using an air freshener in your AC unit to help keep the air smelling fresh and clean.

Conclusion

It’s important to never ignore musty smells in your home, as it could be a sign of an issue with your air conditioner.

Mould and bacteria circulated through your AC system are the same mould and bacteria you and your family are breathing. Research from multiple international studies has found that poorly maintained AC systems are associated with increased upper respiratory symptoms, eye irritation, fatigue and worsening asthma — particularly in children and elderly residents.

The smell is a warning signal. It’s worth acting on it promptly.

Regular maintenance and cleaning can help ensure your AC runs efficiently and smells fresh all year. A professional air conditioner cleaning is the best way to ensure everything works properly and that any lingering odours will be handled quickly. Don’t wait until the problem becomes too big – call The 99 People today!