Start-up is soft start, no impulse current, no waste of electricity. Frequency conversion air-conditioning in operation is the first high-frequency operation heating, when the room temperature reaches the set temperature of air-conditioning, air-conditioning into low-frequency operation heat preservation, non-stop. Continuous low-frequency operation consumes only one third or even one quarter of the rated power. The same is true of refrigeration. Frequency conversion air conditioning does not have very expensive electric auxiliary heating elements.