Does the air conditioning system affect fuel consumption?

As a new driver, I always loved driving around with my Air Conditioning (AC) system switched on.
In the tropics, it is easy to drive without an AC but sometimes it becomes necessary, especially when driving through dusty roads, rain or hot weather conditions.
Driving with wind screens rolled up inside a well flaunted car with sufficient supply of fresh air from the AC, is quite comforting and fulfilling.
However, because of ignorance, I believed a widely told narrative that ACs consume lots of fuel, which for a time made me stop running it in my own car.
But even then, I stayed a bit curious as I had not noticed it myself. I believed it was an unfounded narrative that I needed to fully understand and find out how much fuel the AC can consume at a particular time.
My curiosity brought me in contact with a number of people, most of whom told me their layman’s view until Richard Wandawa, the technical manager at City Tyres explained the AC analogy during one of our many interactions.
The AC, he told me, is a necessity, especially when the car is travelling at a high speed.
According to Wandawa, when a car is travelling at a high speed it pulled back by relative resistance caused by alternative wind movements.
However, he says, the resistance is much more energised if the wind screens are lowered as the wind which is designed to slip off the car’s surface, finds itself inside thus requiring the car to use more fuel to generate more power to cut through the wind.
Therefore, as Wandawa explains, it is more cost effective to drive with wind screens rolled up.
Of course in such circumstances supply of fresh air supply remains a challenge, but can be solved by the AC, which contrary to popular belief, according to Wandawa consumes less fuel compared to when you drive with wind screens lowered down.
The AC also provides much power and lightens up the engine as it siphons out excess air.
Therefore, instead of driving in a sweltering hot car, switch on the AC to get fresh supply of air without worrying about your fuel.