All too often people turn on their air conditioners for the first time in a while, only to be hit with that all-too-common musty smell. That smell is one of the key tell-tale signs that your aircon needs more than just a simple filter cleaning – it needs a deep clean.
While keeping your filters clean is crucial – they’re the first line of defense for capturing lint and other large particles – they can’t stop everything. The real problem starts deeper inside the unit.
Musty smell from mould and bacteria
The most common reason customers call Zamp is because their aircon smells musty, mouldy, or damp. Here in Townsville, we’ve got the perfect recipe for this problem: high humidity, warm temperatures, and aircon units that run hard for a good portion of the year.
When your aircon is running, it pulls moisture from the air. That moisture collects on the evaporator coils (the fins inside the unit which sit underneath the filters). The cooling process makes these internal coils extremely cold, dropping well below the air’s dew point. In our humid, tropical climate, this means condensation – a lot of it.
The air in your house naturally contains dust, pollen, fabric fibers, and lint. While the filter will collect what it can, small particles make their way through the unit and land on the moist and damp coils. When that water mixes with this grime, it creates a thick, “dirty muddy mess” deep inside your machine.
Over time, this moisture and collection of material provides the food and water that mould and bacteria need to survive. Don’t forget, when you switch the unit off, water that doesn’t make its way down the drain sits and festers. That’s what’s causing the smell, and it’s why a deep clean is so important.
Here you can see a dirty filter – we can all clean that (and should), but underneath – yuck. More slime, mould and mess is living on the evaporator coils.
Here is a before and after of the same evaporator coils after a deep clean:
- BEFORE – slime, mould and mess on the evaporator coils, leading to musty odour
- AFTER – professionally deep cleaned and treated – notice the colour difference – WOW!
A professional deep clean will wash the evaporator coils. The air that you’re breathing will no longer be passing over muddy, mouldy coils. You wouldn’t drink from a dish sponge, so why would you breathe air from this aircon?
Grease and smoke buildup
Most households have aircons in their lounge room, sometimes in their kitchens. We’ve all cleaned kitchens before and found the grease that’s settled on top of kitchen cupboards – have you ever wondered how much is collected by an aircon?
The short answer is – a lot. Units in kitchens, and lounges in relatively close proximity to the kitchen, generally smell musty even after one year between cleans. When cleaning these units, the main cause has often been grease buildup which has started to go off and smell rancid.
Grease lands on the fine fins and creates a greasy mess in the unit. It further helps to collect lint, mould, and bacteria that land in the unit. This is why at Zamp we wash the covers inside and out – grease, grime, and mould that build up on the case all impact air quality.
Poor airflow
While blocked and choked evaporator coils are a major cause of poor airflow, they aren’t the only component that needs a deep clean.
Meet the blower fan. Virtually impossible to reach, it’s nested deep within the unit and is responsible for circulating the cool air from the evaporator coils, down through the plastic airway, and into your family home
Heightened allergies
For anyone who suffers from allergies, you know it’s more than just a minor annoyance – it can be a serious source of daily grief. A foundational method for finding relief is to minimise your exposure to the allergens that set you off.
But what about the air you breathe?
Your air conditioner, with its constant cycle of (tropical) damp but cooled air, is a potential candidate for becoming an allergen factory. That “dirty muddy mess” of dust, mould spores, lint, and general grime isn’t just sitting there; it’s a concentrated collection of potential triggers.
Every time you switch on your aircon, the blower fan helps move these microscopic particles around and actively circulates them throughout your home. This can be a direct cause of allergy flare-ups. Many of Zamp’s customers have reported that they suffer from allergies and have found that getting their aircons professionally deep-cleaned at least once a year helps significantly reduce their “allergen load” and provides welcome relief.
Common DIY mistakes to avoid
Most customers switch the aircon on and off, and call Zamp when they’re sick of the musty smell. Other customers note the mould buildup and attempt to treat this themselves. People have tried spray disinfectants from the supermarkets and other aerosols sprayed in the unit, or used methylated spirits to wipe mouldy blades on the front.
These treatments could help a bit (as does filter washing), but they don’t reach the problem area which is the evaporator coils and drainage system deep inside the unit. Spraying chemicals inside the unit without washing could result in accumulation of chemicals that could lead to corrosion of sensitive components and damage to your system – not recommended.
The solution: professional deep cleaning
If you’re handy and want to try a basic clean, start with your filters. Turn off the unit, open the front cover, take out the filters, and wash them with warm soapy water. Let them dry completely before putting them back.
But here’s the thing: cleaning the filters only tackles surface dirt. The mould, grease, and grime causing that musty smell is on the evaporator coils, in the blower fan, and in the drainage line – places you can’t easily reach without the right tools.
That’s where professional cleaning comes in. At Zamp, we use specialised equipment and antimicrobial treatments to deep-clean the coils, flush out the drainage system, and sanitise the unit. We only invest in the best quality cleaners and equipment, meaning we use:
- pH neutral cleaning detergent which is especially designed for the sensitive evaporator coils
- Special mould and bacterial agents designed to kill these organisms, protecting us as cleaners and reducing odours in your unit
- Specialised equipment that uses enough pressure to remove biofilms, but is safe for the sensitive plastic components of split system and box aircon units
- Physical removal techniques – sometimes you need to get in there with a toothbrush and actually scrub to remove the mould
If your aircon is musty, don’t wait. It’s not going to get better on its own, and the longer you leave it, the mustier it’s going to get. Zamp is here and happy to help. Book professional deep cleaning of your aircon today.
