One time when I decided to take a flight across the country, the flight was slightly delayed when we were already on the runway.
The pilot said we would have to wait a little while since there were a lot of planes in line to take off. That’s when the engines were shut off, evidently, to save fuel. I mean, I guess that makes sense because planes will need a certain amount of fuel and they would want to reserve fuel whenever possible. The thing about it is that the air conditioning suddenly seemed very lacking. I remember asking one of the flight attendants about why the AC system seemed to shut off. It was explained to me that when the engines were shut off, the auxiliary power was turned on to provide enough cooling and electricity in the cabin. It wouldn’t be until the flight took off til we could feel a huge difference in airflow and have much better air conditioning on the flight. I learned that airplane air conditioners are not exactly like AC systems in cars. AC systems on flights apparently mix hot and cold air to provide the most suitable temperatures. In a car, your climate control system will provide either heated air or cold air to achieve the desired temperatures. Well, we waited at least 30 minutes before taking off and I felt miserable the entire time. I did notice the huge difference in air conditioning when we finally took off though. It didn’t even take long for the AC to be cranking to just the right level and I was able to rest on the flight all the way to our destination with the ideal temperature control settings.