Bob is an English student. He is going to study in South America for a few years. This is his first day there. He must find a warm room to live in. It is evening now. He is walking along a street with a map in his hand. Then he sees a small board in front of a house. On the board are the words ROOM TO LENT(出租). He thinks the windows are on the south side and the sun will come into the room during the day. So he is going to take it. But in fact he is wrong. Do you know why?
在这篇短文中,He thinks the windows are on the south side .这句话应该怎样理解?

他想窗户是朝南边开的

他想窗户是在南边。