Australia is no stranger to extreme weather, but in recent years, heatwaves have become longer, hotter, and more frequent. When the Australian heatwave weather warning is issued, air conditioners become more than a comfort appliance; they turn into an essential system for health, safety, and daily functioning.
During extreme heat, air conditioners are pushed to their limits. Continuous operation, high outdoor temperatures, and increased indoor heat load can lead to reduced efficiency, higher energy bills, unexpected breakdowns, and even complete system failure. Proper care before and during a heatwave can make the difference between a cool, safe home and an uncomfortable or even dangerous situation.
This guide explains how to take care of air conditioners during a heatwave, covering preparation, daily operation strategies, maintenance tips, energy efficiency practices, and what to do if things go wrong.
Why Heatwaves Are Hard on Air Conditioners
Air conditioners work by removing heat from inside your home and releasing it outdoors. During a heatwave, this process becomes much more challenging because:
- Outdoor temperatures are extremely high, reducing heat transfer efficiency
- Systems run for extended hours without rest
- Indoor heat sources increase cooling demand
- Electrical grids experience peak load
- Components such as compressors and fans operate under stress
Unlike normal summer days, heatwaves can push air conditioners beyond their designed operating range. Without proper care, this can result in overheating, frozen coils, refrigerant issues, or complete shutdowns.
Preparing Your Air Conditioner Before a Heatwave
1. Inspect the System Early
Preparation should start before temperatures spike. Once a heatwave begins, technicians are in high demand, and minor issues can quickly escalate into emergencies.
Check for:
- Unusual noises
- Weak airflow
- Inconsistent cooling
- Water leaks
- Error codes on the thermostat or unit
If something feels off, addressing it early reduces the risk of breakdown during extreme heat.
You can call professional air conditioning technicians to take a look and fix all the issues.
2. Clean or Replace Air Filters
Dirty air filters are one of the most common causes of poor performance during heatwaves. When filters are clogged:
- Airflow is restricted
- The system works harder
- Cooling efficiency drops
- Energy consumption increases
During summer or heatwave conditions, filters should be checked every 2–4 weeks and cleaned or replaced as needed. Clean filters allow smoother airflow and reduce strain on the system.
3. Clear the Outdoor Unit
The outdoor condenser unit needs adequate airflow to release heat. Over time, leaves, dust, grass, and debris can accumulate around it.
Before a heatwave:
- Clear at least 60 cm of space around the unit
- Remove leaves, dirt, and debris
- Ensure vents and fins are unobstructed
Restricted airflow can cause the system to overheat and shut down during peak temperatures.
Smart Thermostat Settings During Extreme Heat
4. Avoid Extreme Temperature Settings
Setting your air conditioner too low during a heatwave does not cool your home faster — it only puts unnecessary strain on the system.
A healthy temperature difference is:
- 24–26°C indoors when outdoor temperatures exceed 40°C
Trying to maintain 16–18°C during extreme heat can:
- Overload the compressor
- Cause freezing of internal coils
- Increase the risk of breakdown
Moderate settings protect both the system and your electricity bill.
5. Use Timers and Scheduling
Running the air conditioner continuously at full capacity is one of the fastest ways to wear it out.
Instead:
- Cool the house early in the morning
- Maintain a steady temperature through the day
- Allow slight temperature increases during peak afternoon heat
Using programmable timers or smart thermostats helps reduce system stress while maintaining comfort.
Reducing Cooling Load Inside the Home
6. Block External Heat
The less heat entering your home, the less your air conditioner has to work.
Simple steps include:
- Closing curtains and blinds during the day
- Using reflective window coverings
- Sealing gaps around doors and windows
- Installing door snakes or weather stripping
These measures significantly reduce heat gain and help the air conditioner maintain temperature more easily. Learn more here.
7. Minimise Internal Heat Sources
Every heat-generating appliance adds extra work for your air conditioner.
During heatwaves:
- Avoid using ovens and stovetops during the day
- Limit use of dryers, dishwashers, and irons
- Switch off unnecessary lighting and electronics
Cooking during cooler evening hours and using energy-efficient appliances can noticeably reduce indoor heat load.
8. Create Cooling Zones
Cooling unused rooms wastes energy and puts unnecessary pressure on the system.
To optimise performance:
- Close doors to unused rooms
- Focus cooling on occupied areas
- Use zoning systems if available
Zoning improves comfort while extending the lifespan of your air conditioner during extreme conditions.
Supporting Your Air Conditioner During Heatwaves
9. Use Fans Alongside Air Conditioning
Ceiling fans and pedestal fans improve air circulation and enhance cooling effectiveness.
Benefits include:
- Better distribution of cool air
- Ability to raise thermostat by 2–3°C without discomfort
- Reduced load on the air conditioner
Fans do not replace air conditioners during heatwaves, but they significantly support them.
10. Ventilate During Cooler Hours
When outdoor temperatures drop overnight:
- Open windows to release trapped heat
- Allow cool air to circulate naturally
- Turn off or reduce air conditioning where possible
This gives the system a chance to rest and recover before the next hot day.
11. Avoid Short Cycling
Turning the air conditioner on and off repeatedly can be harmful.
Short cycling:
- Increases wear on components
- Reduces efficiency
- Prevents proper dehumidification
It’s better to maintain a steady, moderate temperature rather than switching the system on and off frequently.
Daily Maintenance During a Heatwave
12. Monitor System Performance
During extreme heat, small issues can escalate quickly. Pay attention to:
- Sudden loss of cooling
- Unusual smells or sounds
- Reduced airflow
- Ice buildup on indoor units
If you notice these signs, turning the system off briefly and seeking professional advice may prevent permanent damage.
13. Keep Indoor Units Clean
Dust buildup on indoor vents and coils reduces efficiency.
Regularly:
- Wipe vents and covers
- Ensure air pathways are clear
- Avoid blocking vents with furniture or curtains
Clean indoor units allow smoother airflow and reduce operational strain.
Energy Efficiency and Cost Control
14. Manage Peak Energy Demand
Heatwaves often coincide with peak electricity usage, increasing the risk of outages and high energy costs.
To manage demand:
- Avoid running multiple high-energy appliances at once
- Use timers to shift cooling load outside peak hours
- Keep temperature settings realistic
Efficient operation benefits both your household and the wider power grid.
15. Insulation Matters More Than Ever
Good insulation helps maintain indoor temperatures longer, reducing reliance on air conditioning.
Check:
- Roof insulation
- Wall insulation
- Sealed ceiling and wall penetrations
Insulation improvements can significantly reduce cooling demand during heatwaves.
Preparing for Power Outages and Failures
16. Have a Backup Cooling Plan
Despite preparation, power outages and system failures can still occur during heatwaves.
Prepare by:
- Identifying the coolest room in your home
- Keeping battery-operated or rechargeable fans
- Having cool packs and water available
South-facing rooms or shaded areas are often the coolest during the day.
17. Know Your Local Cooling Centres
During severe heatwaves, councils often open public cooling centres such as:
- Libraries
- Community centres
- Shopping centres
Knowing the nearest option in advance can be crucial for vulnerable individuals.
Protecting Health While Using Air Conditioners
18. Maintain Proper Hydration and Air Quality
Air conditioners can dry indoor air, increasing dehydration risk.
To stay healthy:
- Drink water regularly
- Avoid overly dry environments
- Clean filters to maintain air quality
Balanced cooling is essential for both comfort and wellbeing.
19. Avoid Overcooling at Night
Sleeping in extremely cold rooms during a heatwave can cause:
- Respiratory discomfort
- Muscle stiffness
- Increased energy use
Night-time temperatures around 24–25°C are usually sufficient for rest and recovery.
After the Heatwave: Post-Event Care
20. Check the System After Extreme Use
Once the heatwave passes:
- Inspect filters again
- Check outdoor unit condition
- Listen for unusual noises
Heatwaves place prolonged stress on air conditioners, and post-event checks help catch issues early.
You can get your air conditioners professionally repaired and serviced too.
Conclusion
An Australia heatwave weather warning signals more than extreme temperatures — it’s a reminder to protect your home, health, and cooling systems. Air conditioners are built to handle summer heat, but heatwaves demand extra care, smarter operation, and proactive maintenance.
By preparing early, using realistic temperature settings, reducing indoor heat load, supporting your system with fans and insulation, and planning for emergencies, you can keep your air conditioner running efficiently when it’s needed most.
Taking care of your air conditioner during a heatwave isn’t just about comfort — it’s about safety, reliability, and long-term system health in an increasingly hot climate.