Similarities: Bus Coach Air Conditioning System of Electric and Conventional I. Working Principle (How does air conditioning work in a bus?) Heat exchange underlying principle: Both types of bus coach air conditioning systems follow the heat exchange principle for cooling. In this process, the evaporator is responsible for absorbing heat inside the bus. It then causes it to be transferred to the refrigerant. While the condenser is responsible for releasing the heat from the refrigerant outside the bus. In this process, the refrigerant is continuously compressed, condensed, throttled and evaporated through the action of the compressor. When the air conditioner is running, this process will cycle back and forth. The air conditioner is then able to continuously transfer heat from inside the bus to outside the bus. This achieves lower temperatures and increased comfort inside the bus. Both electric and engine-driven compressors play a key role in the air conditioning system. II. Contro...