Noida AC blast: Your apartment could be at risk — Why high-rise AC fires spread so fast

A suspected air-conditioner blast sparked a fire in a 21st-floor flat in Noida's Sector 119 on Monday, once again raising concerns about fire safety in high-rise buildings.

Six fire tenders and 15-20 firefighters were deployed, and the family escaped unhurt after noticing the blaze, which was contained within 30 minutes. The fire remained confined to the flat, though smoke spread up to two floors above.

The incident follows two recent high-rise fires in Noida and Ghaziabad, both suspected to have been triggered by an AC short circuit or other household ignition sources. So why are AC-related fires particularly dangerous in tall residential towers?

Why do ACs blast in peak summer? 

AC blasts are commonly caused when air conditioners keep running continuously without maintenance, and improper servicing or refrigerant refilling in AC units.

Some other reasons include overloaded circuits or extension boards, faulty or ageing wiring, loose electrical connections, poor-quality plugs or cables, voltage fluctuations damaging electrical components, and dust accumulation inside electrical appliances. 

Why are high-rise buildings at greater risk? 

AC blasts are particularly dangerous in high-rise buildings as fire spreads rapidly through the 'chimney effect' as stairwells, lift shafts, service ducts, and utility shafts act like vertical chimneys. 

Hot smoke and flames can quickly rise through these spaces, allowing a fire that starts on one floor to impact multiple upper floors within minutes. Firefighting becomes difficult above a certain height as conventional hydraulic ladders and aerial platforms can reach a limited height. 

Once a fire breaks out in higher floors, firefighters largely depend on the building's internal firefighting systems like sprinklers, risers and hydrants. Evacuation of residents, especially elderly people, children and persons with disabilities, takes longer as lifts can't be used in a fire.  

High-rises rely heavily on fire alarms, automatic sprinklers, smoke extraction systems, fire-related doors and pressurised stairwells. Consequences can be severe if these systems are poorly maintained or fail during an emergency. 

Firefighters often have to rescue people from inside the building rather than from outside through windows or balconies, which can be very difficult on upper floors. 

What should the high-rise you live in be equipped with?

High-rise buildings, however, are not inherently unsafe. Buildings that comply with fire safety norms and undergo regular maintenance are equipped with automatic sprinkler systems, smoke detectors and fire alarms, fire-resistant construction materials, dedicated fire escape staircases, wet risers and hydrant systems, and emergency power backup for critical safety equipment. 

What can you do to ensure your safety? 

Running ACs continuously at low temperatures strains the compressor. Thus, it is advisable to maintain indoor temperatures between 24ºC and 26ºC. 

It is advised to let your cooling system rest periodically and keep temperatures set at sustainable levels. You should get your system serviced by qualified technicians and look out for warning signs such as a burning smell, frequent tripping, or unusual vibrations. 

Use only ISI-marked circuit breakers (MCBs) and install a reliable voltage stabiliser to handle power surges. It is also advised to avoid plugging multiple high-power appliances into a single extension board or wall outlet. Ideally, appliances such as ACs, microwaves, geysers and heaters should have dedicated circuits. 

You should avoid using incorrect or low-grade refrigerant, as it is one of the leading causes of compressor failure and pressure-related incidents. Replace your air conditioner if it shows signs of consistent underperformance despite servicing, especially if it is more than 8 years old.