WARM AIR; HIDDEN DAMAGE
How Using Heat in winter with a Mouldy, Dirty Air Conditioner Affects Your Air Quality and Health.
Why is Pre-Season Cleaning Essential for Health and Comfort?
Now that winter is here and your air conditioner is likely running in heating mode, it's crucial to consider the cleanliness of your system. Many people don't realise that using the heating function on a mouldy or dirty air conditioner can significantly impact indoor air quality. If not cleaned before use, your air conditioner can circulate harmful contaminants throughout your home or workplace—especially when it's filled with dust, mould spores, bacteria, and other pollutants.
In this article, we’ll explore how using heat on a dirty air conditioner affects air quality, the health risks involved, and why a professional deep air conditioner clean is essential—especially as we approach the warm, humid season.
The Hidden Dangers Inside a Dirty Air Conditioner
Over time, air conditioners accumulate a wide range of contaminants:
- Dust and dirt
- Pet hair and dander
- Pollen and allergens
- Moisture from condensation
- Mould and mildew
- Bacteria and biofilm build-up
When your air conditioner is left uncleaned—especially after heavy summer use—it becomes the perfect breeding ground for mould growth. Humidity, combined with organic particles and condensation inside the unit, provides the ideal conditions for spores to flourish inside coils, AC covers filters, and drip trays.
When you switch your air conditioner to heat mode, the system doesn’t eliminate these pollutants—it distributes them.
How Heat Mode Can Worsen Air Quality in a Dirty AC
Circulation of Mould Spores and Bacteria
When the heating function is activated, the warm air moving through the dirty system lifts and disperses accumulated mould spores, dust, and bacteria into the indoor environment. This can cause an immediate deterioration in air quality. If you notice a musty or sour smell when turning on your AC, this is often a sign of active mould growth inside the unit.
Amplification of Odours
Warm air intensifies odours. If your air conditioner is dirty or mouldy, heating will amplify any unpleasant smells, such as mildew, stagnant water, or microbial growth. These odours can quickly permeate your home or office and may linger unless the unit is professionally cleaned.
Increased Risk of Respiratory Issues
Using heat on a contaminated air conditioner can pose serious health risks. Polluted indoor air can trigger:
- Asthma attacks
- Allergic reactions
- Persistent coughing
- Sinus issues
- Headaches and fatigue
- Skin irritation
- Long-term respiratory illness
Children, the elderly, and people with compromised immune systems or respiratory conditions are especially vulnerable to poor indoor air quality caused by a mould-infested AC unit.
How to Protect Your Indoor Air Quality
Book a Premium Deep Clean
At Purify Air Con Cleaning, we specialise in removing mould, bacteria, dust, and odours from air conditioners using our Premium Deep Clean service. Our expert technicians clean every internal component, including coils, filters, drip trays, fans, and casing, ensuring your system is not only clean but also safe to use.
Our cleaning process removes harmful contaminants and restores your unit’s performance, improving energy efficiency and indoor air quality in the process.
Regular Maintenance
Pre-season maintenance should be done at least once or twice a year, ideally before heavy usage periods in summer and winter. Regular maintenance prevents long-term build-up of contaminants and reduces the risk of costly breakdowns. Cleaning the filters 3 or 4 times a year helps to.
Watch for Warning Signs
Some common signs that your air conditioner needs cleaning include:
- Musty or damp smell when turned on
- Visible mould or dust inside vents
- Reduced airflow
- Allergy symptoms worsening indoors
- Higher energy bills
- Unusual noises or short cycling
Benefits of Cleaning Your AC Before Using Heat
- Improved indoor air quality
- Healthier breathing environment
- Reduced asthma and allergy triggers
- Elimination of mould and odours
- Greater energy efficiency
- Extended lifespan of your air conditioner
Using heat on a dirty or mouldy air conditioner can significantly compromise the quality of the air you and your family breathe. It may seem like a simple switch from cool to warm, but the unseen dangers inside your system can pose serious health risks.
Trust the professionals at Purify Air Con Cleaning to restore your air conditioning system. Contact us today to schedule your Premium Deep Air Con Clean and breathe easier this winter knowing your system is mould-free, odour-free, and running safely in heating mode.