Hello, police? My car’s air conditioning is broken and I’m on the brink of losing my life. Come and save me quickly. Hey… hey… hey
Although the above paragraph is a joke made up by netizens, it precisely illustrates the importance of car air conditioning in summer. You know, in this season where you go out for 2 minutes and sweat for 2 hours without air conditioning, you really want to die.
However, blowing air conditioning also incurs costs, as blowing at home requires paying electricity bills, and blowing in the car will increase fuel consumption. Therefore, many friends often do not set the air conditioning temperature too low in the car because they want to save some fuel. And this seems to be the idea of the vast majority of people – the lower the air conditioning temperature, the more fuel the car consumes. But is that really the case?
1. How does air conditioning work?
Firstly, let’s introduce how air conditioning operates – when the refrigerant vaporizes, it absorbs heat from the outside, cools the surrounding air, and then the blower sends the cooled air into the car. After gasification, the refrigerant enters the compressor and is compressed, then cooled by the condenser before returning to a low-temperature and high-pressure liquid. It is then throttled and depressurized by the drying bottle and expansion valve before entering the evaporator for gasification, forming a complete cycle.
2. Is the air conditioning volume related to fuel consumption?
From the previous text, it can be understood that only the blower and compressor consume energy during the operation of the air conditioner. The blower is driven by a motor with very low power, and the electricity is supplied by a generator, so it will operate whether you turn on the air conditioner or not. As for the compressor, it consumes the mechanical energy of the engine, which relies on the thermal energy of the fuel. Therefore, the root cause of air conditioning fuel consumption is the operation of the compressor.
In fact, the air volume of the air conditioner depends on the speed of the blower, but because the power of the blower has little to do with fuel consumption, the blowing function has little impact on fuel consumption.
3. Is air conditioning temperature related to fuel consumption?
The impact of different types of air conditioners on fuel consumption varies when the cooling function is activated. There are mainly two types of car air conditioners on the market: fixed displacement air conditioners and variable displacement air conditioners.
Fixed displacement air conditioning
As the name suggests, a fixed displacement air conditioner has a constant power as soon as the compressor is started. So regardless of whether the air conditioning temperature is turned on high or low, fuel consumption remains unchanged.
Variable displacement air conditioning
The output power of the compressor of the variable displacement air conditioner will vary with temperature. The lower the temperature, the greater the output power, and relatively speaking, the fuel consumption will increase.
To sum up, for fixed displacement air conditioning, the fuel consumption when the air conditioning is turned on is fixed and cannot save fuel; For variable displacement air conditioning, to save fuel, do not set the air conditioning temperature too low.
