Why You Don't Suffocate in an Air-Conditioned Room with Closed Windows and Doors

It's a common misconception that staying in an air-conditioned room with all windows and doors closed might cause suffocation. However, air conditioning systems help maintain a comfortable and breathable environment despite these conditions. Here's why you don't run out of oxygen in such a room.

Recirculation of Air

When you're in an air-conditioned space with windows and doors closed, the air conditioning system is working to keep the room cool by recirculating the indoor air. It does this by pulling in air from the room, cooling it, and then sending it back out. While it doesn't produce oxygen itself, the system helps maintain a balanced environment by recirculating the air within the room.

Fresh Air Intake

Many modern air conditioning systems, especially those used in commercial buildings, have a fresh air intake that allows some outdoor air to enter the system. This fresh air helps replenish the oxygen supply and dilute indoor pollutants. Even in a closed room, this small but regular influx of fresh air ensures that the oxygen levels remain sufficient.

Oxygen Consumption

The amount of oxygen consumed by a person during a typical day is relatively small when compared to the total volume of air in a room. In a typical indoor space, there is usually enough oxygen to maintain a breathable environment for several hours, even with all windows and doors closed. The air conditioning system, by keeping the air moving, helps distribute this oxygen more evenly throughout the room.

Carbon Dioxide (CO2) Levels

While we consume oxygen, we also exhale carbon dioxide (CO2). Most air conditioning systems are designed to maintain indoor air quality by managing CO2 levels. They ensure that the concentration of CO2 does not rise to harmful levels. When the CO2 levels do rise, it prompts the system to increase the intake of fresh air, further ensuring a balanced environment.

Summary: While air conditioning systems do not produce oxygen, they play a crucial role in maintaining a breathable environment by recirculating air and potentially introducing fresh air. This prevents suffocation in a sealed room, even if all windows and doors are closed.

Additional Considerations:

Building Infiltration: It's important to note that buildings are not completely sealed. Air conditioners push hot air out, and this air needs to be replaced. Some systems pull in air from other areas of the building or outside, helping to maintain a consistent air supply. Whole House Air Conditioners: In a whole house air conditioning system, the air is redistributed throughout the entire house several times per hour. This means you are exposed to the oxygen present in the whole house, not just the conditioned room. Long-term Survival: In extreme conditions, it's possible to survive in a room with a closed air conditioner for days, thanks to the natural infiltration of air from outside. With a properly functioning whole house system, the survival time could be even longer.

These factors ensure that staying in an air-conditioned room with all windows and doors closed is safe and comfortable, provided the system is functioning correctly.