How to Clean a Car Air Con & Why It Matters

Your car’s air conditioning does more than just keep you cool, it keeps your air clean and fresh. But if it’s starting to smell musty or blow weak air, it might be time for a cleanup.

In this guide, our car aircon service experts show you how to clean the air conditioning in a car step-by-step. From wiping down vents to replacing filters and disinfecting ducts, we’ll cover everything you need to clean a car air con and keep it running like new so you can breathe easy again.

Signs You Need to Clean Your Car Air Con

Not sure if your system is due for a clean? Look out for these signs:

• Unpleasant Smells: A musty or sour odour when the aircon runs.
• Reduced Airflow: Weak airflow even at full blast.
• Warm Air Instead of Cold: Poor cooling performance despite setting it to the lowest temperature.
• Strange Noises: Rattling or whistling sounds from the vents.
• Foggy Windows: Excess moisture inside the car.

Learn more about when your aircon might need a regas in How to Tell If Your Car Aircon Needs Regassing.

Tools You Need

I recommend having most of the following handy when cleaning your car air conditioner:

1. Air Conditioning Cleaner Spray
   • Look for a foaming antibacterial spray designed to clean aircon systems. It kills mould, bacteria, and odours in vents and ducts.
2. Microfibre Cloths and Brushes
   • For wiping down vents and removing dust buildup without leaving lint behind.
3. Vacuum Cleaner with Hose Attachment
   • Helps suck out dirt and debris from vents and air ducts.
4. Screwdriver Set
   • Handy if you need to remove panels to access filters or deeper parts of the system.
5. Replacement Cabin Air Filter
   • If your filter is clogged, it’s best to replace it rather than clean it.
6. Bucket of Warm Soapy Water
   • Useful for cleaning removable components like vent covers.
7. Gloves and Safety Mask
   • Protects you from inhaling dust, mould spores, or harsh chemicals.

How to Prepare Your Car

1. Turn Off the Engine and Aircon
   • Always work on the air conditioning system with the car completely off for safety.
2. Open Windows and Doors
   • Ensure proper ventilation while you work, especially if using cleaning sprays.
3. Remove Mats and Clear the Interior
   • This gives you space to move around and reduces the chance of dirt spreading inside the car.
4. Locate the Cabin Air Filter
   • Most filters are behind the glovebox, but check your car manual for the exact location.
5. Inspect Drain Hoses
   • Check under the car for the aircon’s drain hose. A clogged hose can trap moisture and cause mould, so make sure it’s clear.
6. Test Airflow Before You Start
   • Turn on the aircon briefly to assess how well it’s currently working. This helps you spot improvements after cleaning.

Important Safety Tips

• Read the Labels – Follow instructions on cleaning sprays, especially if they need rinsing afterward.
• Avoid Electrical Damage – Be careful not to spray liquids directly into electrical components.
• Wear Protection – Gloves and masks protect against chemicals and allergens.

How to Clean a Car Air Conditioner

Step 1: Clean the Air Vents

1. Dust and Vacuum
   • Use a soft brush or vacuum with a small nozzle to remove visible dust from the vents.
2. Wipe Down with a Microfiber Cloth
   • Dampen the cloth slightly with warm soapy water and wipe the vents clean.
3. Apply an Anti-Bacterial Spray
   • Spray the cleaner directly into the vents while the fan is running on low.
   • Let it circulate for 10–15 minutes to kill bacteria and eliminate odours.

Step 2: Replace or Clean the Cabin Air Filter

1. Locate the Filter
   • Usually found behind the glovebox—check your car’s manual for guidance.
2. Remove and Inspect It
   • If it’s clogged with dirt or debris, replace it with a new one.
   • If it’s lightly dirty, clean it with compressed air or rinse it gently (if washable).
3. Reinstall the Filter
   • Ensure it’s fitted properly to maintain airflow efficiency.

Step 3: Clean the Evaporator Coils

1. Access the Coils
   • Depending on your car model, you may need to remove the blower motor or panels under the dashboard.
2. Spray Foaming Cleaner
   • Apply a foaming aircon cleaner directly onto the evaporator coils.
   • Let it soak for the recommended time (usually 10–15 minutes).
3. Run the Fan
   • Turn the fan on high for 10 minutes to allow the cleaner to circulate and clear out residues.

Step 4: Test and Recharge the Air Conditioning (Optional)

1. Turn On the Aircon
   • Check if the airflow and cooling have improved after cleaning.
2. Recharge Refrigerant if Needed
   • If cooling is still weak, it might need a regas service to top up refrigerant levels.
   • Voltaic offers a $199 aircon regas service to restore performance​Voltaic Services.

How to Maintain Your Car Air Con

• Clean Regularly: Clean vents and filters every 6–12 months to keep the system in top shape.
• Run the Aircon Weekly: Even in winter, running the system briefly prevents moisture buildup.
• Schedule Professional Servicing: For deeper cleaning and diagnostics, let the experts handle it.

Why Cleaning Your Car’s Air Conditioning Matters

1. Eliminates Bad Odours

Ever turned on your aircon and been hit with a musty smell? That’s usually caused by mould or bacteria growing in the system. Cleaning it out keeps the air fresh and pleasant.

2. Improves Cooling Efficiency

A dirty system has to work harder to push out cool air. Cleaning the vents, filters, and ducts restores efficiency, so your car cools down faster without overworking the compressor.

3. Extends the Life of Your Aircon

Regular maintenance prevents blockages and wear, saving you from expensive repairs or replacements down the track.

4. Promotes Healthier Air Quality

Mould and bacteria lurking in your aircon can trigger allergies or respiratory issues. Cleaning the system reduces these risks and keeps the air you breathe safe.

How Do Car Air Conditioning Systems Get Dirty?

Your car’s aircon pulls in air from outside, passing it through filters and ducts. Over time, dust, pollen, and moisture accumulate, providing the perfect environment for bacteria and mould to thrive.

• Cabin Air Filters: Trap dirt and debris but can clog if not replaced regularly.
• Evaporator Coils: Condensation can cause mould buildup, leading to musty smells.
• Vents and Ducts: Dust and grime collect in the air pathways, reducing airflow.

For more on air conditioning issues, check out Why Does the Air Conditioning in Your Car Smell?

Breathe Easy with Voltaic’s Aircon Services

Keeping your car’s aircon clean doesn’t just improve comfort—it protects your health and your vehicle’s performance. If you want a thorough, professional clean or need an aircon regas, book a $199 car aircon service with Voltaic Auto Electrical today​.