Mould in Air Conditioners in India: Causes, Detection, Prevention, and Remedies

Mould growth in air conditioners is a common issue, particularly in humid regions like many parts of India. This article will delve into the causes, methods of detection, signs to look out for, preventive measures, and steps to eliminate mould from air conditioners.

Causes of Mould in Air Conditioners

  1. Humidity and Moisture: High humidity levels in the air provide a perfect environment for mould growth. Air conditioners can create condensation, especially if they are not maintained properly, leading to moisture build-up.
  2. Poor Ventilation: Inadequate ventilation can trap moist air inside the unit, contributing to mould growth.
  3. Dirt and Debris: Dust, dirt, and organic debris can accumulate inside the air conditioner, providing a food source for mould spores.
  4. Stagnant Water: Water stagnation due to blocked drainage can create a damp environment conducive to mould growth.

Detection of Mould in Air Conditioners

  1. Visual Inspection: Regularly check the air conditioner components such as the filters, coils, and ducts for any visible signs of mould.
  2. Odor: A musty smell emanating from the air conditioner when it’s running is a strong indicator of mould presence.
  3. Health Symptoms: Increased incidence of respiratory issues, allergies, or other health problems when using the air conditioner can suggest mould contamination.
  4. Professional Inspection: For thorough detection, hiring a professional to inspect and test the air quality might be necessary.

Signs of Mould in Air Conditioners

  1. Musty Odor: Persistent musty or earthy smells when the air conditioner is operating.
  2. Visible Growth: Dark spots or patches visible on the unit or vents.
  3. Increased Allergy Symptoms: Symptoms such as sneezing, coughing, runny nose, or skin irritation that worsen when the air conditioner is on.
  4. Reduced Airflow: Mould can obstruct airflow, causing the air conditioner to work less efficiently.

Prevention of Mould in Air Conditioners

  1. Regular Maintenance: Schedule regular maintenance to clean and inspect the air conditioner components.
  2. Humidity Control: Use dehumidifiers in areas with high humidity to reduce moisture levels.
  3. Proper Ventilation: Ensure adequate ventilation in the room where the air conditioner is installed.
  4. Clean Filters: Regularly clean or replace air filters to prevent the accumulation of dust and debris.
  5. Drainage Maintenance: Ensure the drainage system is clear and functional to prevent water stagnation.
  6. UV Lamps: Installing UV lamps inside the air conditioner can help to kill mould spores and other microorganisms.

What to Do If You Detect Mould

  1. Turn Off the Unit: If mould is detected, turn off the air conditioner to prevent further spread of spores.
  2. Personal Protective Equipment (PPE): Wear gloves, a mask, and protective eyewear when dealing with mould to prevent inhalation or contact.
  3. Clean the Unit: Use a mixture of water and detergent to clean the visible mould. For more stubborn mould, a mixture of bleach and water (1 part bleach to 10 parts water) can be used.
  4. Replace Filters: Replace any affected filters with new ones.
  5. Professional Cleaning: For extensive mould infestations, it is advisable to call a professional HVAC technician to thoroughly clean and disinfect the unit.
  6. Dry the Unit: After cleaning, ensure the unit is completely dry before turning it back on to prevent new mould growth.


Mould in air conditioners is a significant issue, especially in the humid climate of India. Regular maintenance, proper ventilation, and immediate action upon detection are key to preventing and eliminating mould. By taking these steps, you can ensure a healthier indoor environment and a more efficient air conditioning system.


This content is collaboratively crafted and vetted by Shubham, a Mechanical Engineering specialist. His passion for unraveling the intricacies of machinery and consumer electronics mirrors his avid interest in gaming. With his wealth of expertise, Shubham adeptly navigates readers through the complexities of audio, home appliances, and everyday products, guaranteeing a smooth and enjoyable shopping journey. For every product you read about on this site we do rigorous research and testing behind the scenes to bring you the best value for money options. For any query directly reach out to me at my personal Instagram -

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