Why Does Using Air Conditioning in a Car Consume More Fuel?
2 Answers
The reason why using air conditioning in a car consumes more fuel is as follows: This is related to the compressor in the car, as the presence of the compressor means that the car's air conditioning does not consume electricity but rather fuel. The compressor of a car's air conditioning system is a crucial component for its operation and also a major energy consumer in the entire air conditioning system. Generally, electric compressors are used in electric vehicles, while in traditional fuel-powered cars, the compressor is typically connected to the engine's crankshaft via a belt, rather than being electrically driven. This is the main reason why using air conditioning consumes more fuel. Relevant information is introduced as follows: The up-and-down movement of the car engine's pistons drives the crankshaft to rotate through connecting rods, thereby converting the chemical energy in gasoline into mechanical kinetic energy. In addition to connecting to the transmission to provide power, the other end of the crankshaft also drives components such as the air conditioning compressor, generator, and coolant pump via a belt.
The issue of cars consuming more fuel when the air conditioning is on boils down to the engine taking on extra work. The compressor is connected to the engine via a belt, so turning on the AC is like adding a small task to the engine's workload. Cooling requires the compressor to vigorously compress the refrigerant, a process that demands additional power—roughly 3 to 5 horsepower. To compensate, the engine burns more fuel. This effect is especially noticeable in small-displacement cars; when idling at a red light or climbing a hill, turning on the AC immediately causes the engine RPM to rise, and throttle response becomes noticeably sluggish. The fan and condenser also consume electricity, adding to the energy the alternator draws from the engine. The lower you set the AC temperature, the harder the compressor works, and the more fuel gets burned. I think older cars are affected more significantly, as their outdated compressor technology makes the vehicle feel noticeably sluggish when the AC is running.
