Idling the automobile places tension on the modern-day energy injection systems in today's automobiles. Idling was used in cold or heats when fuel injection had not been widespread in older autos. To keep the engine from stalling, people used to keep it running or it could not activate.
If you truly require the auto to maintain keeping up the Air Conditioning on in summer seasons, maintain giving revs to the car to ensure that the engine runs more and oil circulates inside the engine. Given that India is a very moist country, AC is always on, but try utilizing it much less usually since it places tension on the vehicle components and also you wish to prolong the life of your vehicle don't you?