How to distinguish feng shui, evil wind and yang wind?

There is a difference between evil wind and yang wind. He Guangting said in Corrected Geography in the late Qing Dynasty: "Pingyang is not afraid of the wind, but there is a difference between Yin and Yang. The warm wind blowing from the east to the south is also called the yang wind. The cold wind from west to north is called the evil wind, so it is advisable to stop it with the recent case, otherwise the wind will blow the bones and the main family will be defeated. " This is to avoid the northwest wind.