Can Sleeping With AC On Be Risky? Gas Leak And Poor Ventilation Can Be Deadly | Explained | Lifestyle News

Last Updated:July 07, 2025, 17:28 IST

If a leak occurs and R-32 gas concentration reaches 13–29% in the air, it can ignite in the presence of a spark, lighter, or electrical switch, leading to a potential fire

In a tragic incident just two or three days ago, four air conditioning mechanics lost their lives due to a gas leak in a house in Delhi. This is not an isolated event; similar accidents have occurred in India and around the world. In 2022, three people died from an AC gas leak in a hotel in India, and in 2020, five members of a family perished in Karachi, Pakistan due to the same cause.

Such incidents are rare but do surface from time to time. In most cases, the cause is gas leakage from an air conditioner, leading to suffocation of people sleeping in the room. In some countries, fatalities have been linked to unauthorized AC gas refilling or poor ventilation in enclosed spaces.

Generally, air conditioners (ACs) used in homes and offices are safe, but in certain cases, they can pose serious risks, especially if:

• There is a gas leak in the AC
• Proper ventilation is lacking
• The AC is old or poorly maintained

Although the ACs installed in homes are generally safe, accidents can still occur in rare cases.

Should The Room Be Completely Closed While Running An AC?

• While an air conditioner is running, keeping doors and windows closed helps retain cool air and maintain room temperature efficiently, also reducing power consumption.
• However, if the AC operates throughout the night, there should be some provision for ventilation. Leaving the door slightly open can help.
• Proper ventilation is essential. In case of an AC gas leak, there should be a way for the air to circulate and fresh oxygen to enter.
• When a person stays in an air-conditioned room for several hours, the door should be opened occasionally to allow fresh air in. This helps maintain adequate oxygen levels and prevents a rise in carbon dioxide.
• Rooms should never be sealed completely without ventilation.
• Fresh air should be allowed into the room for at least 5 minutes every 2–3 hours.
• A refrigerant leak test should be included during regular AC servicing.
• Checking for gas leaks and servicing the AC once or twice a year is strongly recommended.

Which Gas Is Used In Air Conditioners?

• R-22 (Chlorodifluoromethane – HCFC): Commonly used in older AC systems, but now banned due to its harmful effects on the ozone layer.
• R-410A (Pyron, Purerefrigerant): Widely used in modern air conditioners. It is ozone-friendly but has a high global warming potential.
• R-32 (Difluoromethane – HFC): Found in newer inverter ACs. It has minimal impact on the ozone layer and is more energy-efficient, but also comes with some safety concerns.
• R-290 (Propane – Hydrocarbon refrigerant): Considered the most environmentally friendly option, with negligible ozone damage. However, it is flammable and requires careful handling.
• R-134A (Tetrafluoroethane – HFC): Commonly used in automobile ACs and some portable units. It does not harm the ozone layer but contributes significantly to global warming.

Gases Used In Early Air Conditioners

• R-12 (Dichlorodifluoromethane – CFC): Commonly used in air conditioners from the 1930s to the 1990s. Extremely harmful to the ozone layer, it was banned under the Montreal Protocol.
• Ammonia (NH₃): Utilised in early refrigeration systems. Due to its toxic and explosive nature, it is not suitable for use in domestic air conditioners.

When Does R-32 Become Dangerous?

R-32 (Difluoromethane) is a hydrofluorocarbon (HFC) refrigerant commonly used in modern inverter ACs. While it is ozone-friendly, it is mildly flammable. In the event of a leak, if the gas concentration in the air reaches between 13% and 29% and an ignition source—such as a spark, lighter, or electrical switch—is present, it can catch fire.

Who Should Be Especially Cautious?

• Elderly individuals
• Young children
• People with asthma or respiratory issues
• Individuals who spend extended hours in air-conditioned rooms

Some Major Accidents Involving Air Conditioners

• Chennai (October 2018): A family of three—husband, wife, and their 8-year-old son—died in their sleep after gas leaked from an inverter AC when the power returned. With the room locked, they suffocated due to the gas build-up.
• Vijayanagar, Karnataka (April 2022): A gas leak at night followed by a short circuit triggered a fire in the AC, resulting in the deaths of an entire family—parents and two children.
• Mantra, Gujarat (January 2025): A gas leak from the AC caused a fire, killing a father and his 2-year-old daughter. The mother sustained serious injuries.
• Costco Store, United States (April 2024): A refrigerant gas leak created a “white cloud,” causing breathing issues for nearly 1,000 people. Fortunately, all were rescued, and no serious injuries were reported.

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