It is possible to use 4 flat wires for vertical air conditioners, but the cross-sectional area of the wires needs to be determined according to the power size and installation position of the air conditioner. In general, the power of vertical air conditioners is small, and the use of 4 flat wires is sufficient. However, if the power of the air conditioner is large or the installation position is far away from the power supply, it is recommended to use a larger cross-sectional area of the cable to ensure the stability and security of power transmission. At the same time, when installing the wire, it is also necessary to pay attention to whether the laying and wiring of the line meet the safety standards to avoid safety hazards such as overheating and short circuit of the wire.