China is in the northern hemisphere, with the door facing south. The south wind blows-cool in summer, but the north wind can't blow-warm in winter! There is lighting, the sun is from east to west, only facing south, indoor lighting time is the longest in a day, the sun is always in the south, facing the south sun!
The dragon chair of the ancient emperor of China also faces south, and the seat facing south is the most respected!
Ancient people, rich or not, had to face south, and no one was allowed to stand in front, because the god of wealth was in the south!