Retired IAS officer and the first chairman of the Competition Commission of India (CCI), Dhanendra Kumar, 80, died in a fire after a suspected air conditioner (AC) blast at his home in Delhi’s Hauz Khas on Thursday (May 28).

The incident is the latest in a series of AC-related fire accidents reported in the National Capital Region this summer. Just this week, a split AC reportedly exploded and triggered a fire on the 15th floor of a residential tower in Ghaziabad’s Indirapuram.

And, earlier this month, nine people were killed in a blaze at a residential complex in East Delhi’s Shahdara, where initial reports also pointed to an AC blast as a possible trigger.

The incidents call attention to a disturbing pattern increasingly unfolding in Indian cities every summer. With higher average temperatures year-on-year and rising nationwide AC sales, the likelihood of such incidents is increasing. Some simple practices, however, can help ensure safety.

During the summer, continuously running electrical appliances can lead to overheating, also due to the high average atmospheric temperature. This overheating can degrade an AC’s insulation, melt internal components, and ignite combustible materials inside the unit.

Another major reason is short-circuiting, which occurs when the flow of electric current in a circuit takes an unintended path. This is not always dangerous, but when a large amount of current is flowing, it can, in turn, generate a great amount of heat. This can melt wires and lead to a fire.

Generally, MCBs (miniature circuit breakers) are installed to trip the circuit as soon as an overload is detected. The Schneider Electric website states: “MCBs are equipped with a bimetallic strip that is sensitive to heat. If there are high amounts of current flowing through the circuit, it warms up the bimetallic circuit in the MCB, which bends and deflects from its original state. This deflection causes the MCB to ‘trigger’ and release a mechanical latch. This latch disconnects the circuit and disrupts the electrical flow from reaching the connected device.”

Later, the MCB switch can be turned on to resume the normal flow of electricity. This safety mechanism may fail if the MCB is faulty, resulting in fires.

👁 AC blast

The Delhi government’s Department of Fire Services states: “About 60% fires are of electric origin on account of electric short circuit, overheating, overloading, use or non standard appliances.”

According to an official from the Delhi Power Department, house fires are commonly caused by short circuits in electricity meters, switchboards, or due to loose, poor-quality, or faulty wiring. “In AC units, fires usually occur due to gas leakage or overheating in the compressor, which is the outdoor unit. However, in the Hauz Khas incident, the suspected explosion occurred in the indoor unit of the AC, which is uncommon. Sometimes, if there is a spark caused by faulty wiring in a closed room along with a gas leak, it can ignite and lead to an explosion inside the unit as well,” the official said.

In an AC, a compressor (the external box unit with a fan in split ACs) performs a crucial function. It is responsible for circulating a substance called refrigerant gas through the unit, which helps in the expulsion of warm indoor air.

A non-inverter AC uses a fixed-speed compressor that runs at full speed until the room reaches the target temperature, then shuts off completely. When the temperature rises, it turns back on at full speed.

During extreme heat and prolonged use, this creates higher electrical and mechanical stress, which can overheat components such as the compressor, capacitor or wiring. If the unit is old, poorly maintained, or exposed to voltage fluctuations, it can lead to short circuits and fires — often referred to as “AC blasts”.

On the other hand, an inverter AC regulates the compressor speed gradually instead of constantly switching on and off. While this variability reduces stress in the system, it’s not foolproof. Fires can still occur due to overheating of electronic circuit boards, faulty wiring, refrigerant leakage, poor installation, voltage fluctuations or lack of maintenance.

According to Haier, some common signs of a potential blast include unusual noises from the unit, frequent cycling on and off, inconsistent cooling of the room, and burning smells/smoke. Professional repair services should be called in to fix these issues.

In the case of split ACs, both the inside and outside units are potential fire hazards. Usually, the inside unit comprises the evaporator (which removes the heat from the air), the blower and the filter nets. The outside unit includes the compressor.

Here are some dos and don’ts to ensure your AC is in good health:

With inputs from Alok Singh and Rishika Singh