Why does the driving range of the new energy truck decrease when the AC is turned on?

For truck drivers of diesel trucks, using air conditioning does not have a significant impact on the driving range, nor does it cause noticeable power reduction. However, when it comes to electric vehicles, why does the air conditioning become one of the major power consumers?

Since we are talking about power consumption of air conditioning, we have to discuss the power-intensive heating function. First, let's take a look at how electric vehicles achieve heating. In general, most passenger vehicles use heat pump air conditioning and PTC electric resistance heating. However, due to various factors such as cost, trucks do not use heat pump air conditioning and generally use PTC electric resistance heating.

After PTC resistance heating converts electricity into heat, a blower sends hot air into the cab to achieve the heating effect. Usually, PTC heaters are widely used in pure electric vehicles due to their advantages of simple structure, low cost, and fast temperature rise.

Of course, compared to heating in winter for gasoline vehicles, which only requires the excess heat from the engine to be introduced into the passenger compartment, the drawbacks of PTC heating are also very obvious. The higher the temperature setting, the longer the operating time, and the higher the power consumption, which has a significant impact on the driving range of pure electric vehicles.

After talking about heating, how do trucks achieve cooling? When the air conditioning is turned on for cooling, the engine's power is transmitted to the air conditioning compressor through a belt. At this time, the air conditioning compressor compresses the refrigerant, causing the refrigerant to flow and turn the liquid refrigerant into vapor, and then turn the vapor-state refrigerant back into liquid. This process can continuously absorb heat, thereby cooling the air, and then the blower provides cold air for the cab.

The compressor is usually driven by the power of the engine, so the question arises, electric vehicles do not have an engine, to use the drive motor to provide kinetic energy to the compressor? This is obviously not possible, on the one hand, the motor is not working when parked, this time there is no kinetic energy to drive the compressor work. On the other hand, as can be seen from actual pictures of electric vehicles, there are no other devices near the drive motor, which is often arranged separately.

So where does the kinetic energy for the compressor come from? It's actually driven by the electric vehicle's own power cell. The air conditioner in an electric vehicle is basically the same as the parking air conditioner; the electric air conditioning compressor has its own power source, and it only needs to be powered to drive the compressor to work, thus providing continuous cooling for the vehicle.

Both heating and cooling are driven by the power battery that comes with the electric truck itself, so when the air conditioning is turned on, it will directly lead to an increase in power consumption and thus a decrease in driving range.

So, is it necessarily more power-saving not to turn on the air conditioning and cool down by opening the windows? The answer is no, when the vehicle reaches a speed of over 80km/h, a part of the power is used to overcome wind resistance. At this time, if you cool down by opening the windows, it will undoubtedly increase more wind resistance, leading to an increase in power consumption. So, when the car is moving fast, it may still be more power-saving to turn on the air conditioning.

Frequent hard acceleration or long periods of highway cruising are the culprits of shortened range, they cause the drive motor to be under high load for long periods of time, which consumes more power and brings the range down.

Therefore, if you want to save more power, have a longer range, you have to avoid rapid acceleration, violent driving and long time high speed cruising. This is also conducive to the protection of the motor, to avoid motor performance decline, demagnetization and other phenomena, after all, the repair of the motor is pricey.