BENGALURU: Leaving the air-conditioning in your car on while you roll up the windows and rest for a bit is not a good idea at all, according to automobile experts who argue that poisionous gases such as carbon monoxide tend to make their way into the car cabin eventually.
The recent incident in which two people lost their lives when they were in a car parked in a garage with the air-conditioner on and the windows rolled up has made many vehicle users wary about sitting in a stationary car with the cooling mechanism on.
Similar cases have been reported in the past, especially during the monsoons when vehicles get stranded in the rain and the owners tend to turn up the windows to keep the water outside and turn on the air-conditioning to stay warm or cool. While this might seem like a good idea at the moment it could quickly turn into a nightmare due to the danger of inhaling carbon monoxide (CO), an odourless, colourless gas which has the capacity to kill in a little under two hours if present in large quantities in a closed area.
“If the car is parked in a closed area, the emissions from the tailpipe are circulating in the room. In such a situation, if the user selects the fresh air setting, the air-conditioner will pull in air from outside the car and the gases will enter the vehicle. It is best to use the recirculation button which ensures that air within the car is recirculated continously,” said Nachiket Rao, who is an automobile engineer.
The recirculation button, which has an arrow that curves inside the image of the car, works without taking in air from outside. Air that has already been cooled within the cabin is taken and run through the evaporator again making it cooler. However, here the risk of carbon dioxide building up in the cabin is always present if the vehicle is stationary. While in a moving vehicle, the driver would roll down the window for recirculation if the car feels stuffy, this won’t be the case if the car is stationary and the people within are asleep, Rao added.
Weak air-conditioner can be fatal too
A faulty or weak air-conditioning system could also lead to fatalities. “The AC also ensures a steady supply of air into the vehicle and any issues with its air filter or other parts could mean that not enough air enters the cabin. It is always advisable to roll down windows from time to time,” said Yusuf, service manager at a car service station. The presence of holes in the vehicle or a badly tuned exhaust emission system could also prove fatal if the vehicle is kept running in an enclosed space for long.
“Carbon Monoxide forms a tighter bind with haemoglobin than oxygen. This means that if both CO and oxygen are inhaled, CO will bind to haemoglobin reducing the amount of haemoglobin that can bid with oxygen leading to a shortage of the life giving gas in the body,” said Dr Varun Singh, an ENT specialist.