How ACs catch fire, and the role temperature plays in it

Why in the News?

A major fire in a residential apartment in Delhi’s Dwarka area, allegedly triggered by an AC blast, led to fatalities during an intense heatwave. The incident has drawn attention to the rising number of air-conditioner fire accidents during summers, as prolonged AC usage and extreme temperatures increase overheating and electrical risks.

What are Air Conditioners (ACs)?

Air conditioners (ACs) are electrical cooling devices that reduce indoor temperature and humidity by removing heat from enclosed spaces and releasing it outside through a refrigeration cycle. 

They work using components such as a compressor, condenser, evaporator, and refrigerant gas to maintain comfortable room temperatures, especially during extreme summers and heatwaves.

Why are AC fire incidents increasing during extreme summers?

1. Heatwave Conditions: Rising ambient temperatures force ACs to operate continuously for longer hours, increasing thermal stress on internal components.
2. Higher Cooling Load: Elevated outdoor temperatures reduce cooling efficiency, compelling compressors to work harder and consume more electricity.
3. Urban Dependence: Increased AC penetration in cities raises cumulative electricity demand and appliance stress, particularly in densely populated apartments.
4. Climate Linkage: More frequent and intense heatwaves have expanded cooling requirements, converting household cooling devices into a potential urban safety concern.
5. Delhi Case Example: The Dwarka apartment fire allegedly linked to an AC blast highlighted the severe consequences of overheating in enclosed residential spaces.

How do air conditioners catch fire?

1. Overheating: Continuous operation during peak summers causes excessive heat generation in internal components, wiring, and insulation systems.
2. Insulation Damage: Excessive heat degrades insulation materials inside the AC, exposing electrical parts and increasing ignition risk.
3. Short Circuits: Electrical current may flow through unintended paths due to damaged wiring, overheating, or loose electrical connections, generating sparks capable of igniting combustible materials.
4. Electrical Overload: Excessive current flow places stress on circuits and electrical systems, increasing fire probability.
5. Faulty Components: Damaged compressors, malfunctioning parts, and ageing electrical systems increase operational risks.
6. Indoor Unit Vulnerability: While external compressor units generally overheat, indoor AC units pose higher fire risks because electrical sparks generated internally can ignite surrounding household materials.

Major causes of AC overheating

How do blocked filters increase fire risk?

1. Blocked Air Filters: Dust accumulation restricts airflow, forcing the AC to work harder and causing overheating.
2. Cooling Inefficiency: Reduced ventilation decreases heat dissipation capacity and elevates internal temperature.

How do electrical faults trigger AC fires?

1. Short Circuits: Loose wiring or damaged electrical circuits create sparks that may ignite nearby combustible materials.
2. Voltage Fluctuation: Irregular power supply damages sensitive AC components and accelerates system wear.
3. Poor Wiring Quality: Faulty or substandard wiring increases overheating probability.

Why are gas leaks dangerous in AC systems?

1. Refrigerant Leakage: Leakage creates pressure imbalances and operational stress that may increase fire vulnerability.
2. Compressor Stress: Improper refrigerant circulation forces compressors to overwork and malfunction.

Why does prolonged usage increase overheating?

1. Extended Operation: Running ACs continuously for long durations during summers overheats internal components.
2. Component Fatigue: Persistent use accelerates wear and malfunction in motors, compressors, and circuit boards.

Are inverter ACs safer than non-inverter ACs?

1. Inverter Technology: Inverter AC compressors regulate speed gradually according to room temperature rather than repeatedly switching on and off.
2. Reduced Stress: Continuous speed modulation lowers operational pressure on electrical components.
3. Energy Efficiency: Inverter systems consume less power during sustained operation.
4. Non-Inverter Limitation: Conventional ACs repeatedly restart compressors at full speed, increasing mechanical stress and overheating risks.
5. Conditional Safety: Inverter ACs are relatively safer but remain vulnerable to poor installation, electrical faults, voltage fluctuation, and lack of maintenance.

What are the warning signs of an unsafe AC system?

1. Frequent Tripping: Repeated circuit breaker shutdown indicates excessive load or electrical faults.
2. Unusual Noise: Buzzing or abnormal sounds may indicate compressor or motor malfunction.
3. Burning Smell: Smell from wiring or components signals overheating.
4. Irregular Cooling: Reduced cooling performance may indicate blocked filters, gas leakage, or compressor problems.
5. Frequent On-Off Cycling: Repeated switching suggests electrical instability or malfunction.

Safety measures that can reduce AC fire incidents

How can maintenance reduce overheating risks?

1. Regular Servicing: Ensures cleaning, component inspection, refrigerant checks, and early detection of faults.
2. Filter Cleaning: Maintains airflow and prevents internal overheating.
3. Dust Removal: Cleaning indoor and outdoor units reduces heat accumulation.

How does electrical protection improve safety?

1. Circuit Breakers: Ensures automatic disconnection during overload or short circuits.
2. Dedicated Wiring: Supports safe electricity flow and reduces overloading.
3. Voltage Stabiliser: Protects AC units from frequent power fluctuations.

What temperature practices improve efficiency and safety?

1. Optimal Temperature Setting: Maintaining temperatures between 24-26°C reduces compressor burden and energy consumption.
2. Controlled Usage: Prevents prolonged continuous operation during extreme heat.

Why does this issue matter for urban governance and climate resilience?

1. Urban Fire Safety: Requires stronger residential electrical audits and appliance safety standards.
2. Climate Adaptation Challenge: Rising temperatures are increasing dependence on cooling infrastructure.
3. Power Infrastructure Stress: Greater electricity demand during heatwaves increases risks of overload and voltage fluctuations.
4. Public Awareness: Safety education regarding AC maintenance and heatwave preparedness remains limited.
5. Building Regulation: Strengthens need for fire-compliant residential design and electrical inspections.

Conclusion

AC fire incidents illustrate how climate change is interacting with urban infrastructure vulnerabilities to create new public safety risks. Rising temperatures, prolonged cooling demand, and inadequate electrical preparedness have increased overheating hazards. Strengthening appliance maintenance, electrical safety compliance, heatwave preparedness, and resilient urban infrastructure remains necessary to reduce climate-linked fire vulnerabilities.

India Cooling Action Plan (ICAP), 2019India Cooling Action Plan (ICAP), launched by the Ministry of Environment, Forest and Climate Change (MoEFCC), is the world’s first comprehensive national cooling strategy aimed at addressing rising cooling demand while ensuring environmental sustainability and energy efficiency.Cooling Demand Reduction: Targets a 20-25% reduction in cooling demand by 2037-38 across residential, commercial, transport, and cold-chain sectors through sustainable cooling technologies and better urban planning. Energy Efficiency: Encourages adoption of energy-efficient cooling appliances, including higher star-rated ACs and sustainable building designs to reduce electricity consumption.Climate Sustainability: Promotes reduction in greenhouse gas emissions and transition toward environmentally safer refrigerants with lower global warming potential. Thermal Comfort for All: Ensures affordable and accessible cooling, especially for vulnerable populations facing heat stress.Skilling and Innovation: Supports workforce development for cooling technicians and promotes domestic manufacturing under sustainable standards. Why is ICAP relevant to AC fire incidents? Reduced Cooling Load: Efficient cooling systems lower overheating risk during prolonged use.Energy Management: Reduced electricity demand decreases chances of voltage fluctuations and electrical overloads during heatwaves.Safer Cooling Infrastructure: Encourages improved appliance efficiency and maintenance practices. National Disaster Management Authority (NDMA): Heatwave Guidelines. The NDMA has issued heatwave management guidelines to reduce mortality, infrastructure stress, and public health risks arising from extreme temperatures. Preparedness: Encourages Heat Action Plans (HAPs) at city and district levels involving early warning systems, emergency coordination, hospital readiness, and inter-agency planning. Early Warning Systems: Facilitates temperature alerts through IMD forecasts to prepare citizens and institutions for extreme heat events. Public Awareness: Promotes behavioural adaptation through advisories on hydration, avoiding peak heat exposure, efficient appliance use, and household safety. Infrastructure Resilience: Encourages cooling shelters, green cover expansion, and urban heat mitigation measures. Vulnerable Group Protection: Prioritises elderly persons, outdoor workers, children, and economically weaker populations during heat stress. Why are NDMA Heatwave Guidelines relevant here? Heatwave-Driven AC Usage: Prolonged extreme temperatures increase AC dependence, overheating risks, and electricity demand. Urban Risk Management: Heat preparedness indirectly reduces appliance-related fire hazards.