However, fung shui ancient books, it has been mentioned that only a small door that should never twinning, or placing of gas from the door into a small, and from another a small door.

• 不过，风水古书中曾提到，小门只能一个，千万不能成双，否则屋宅之气会从一个小门进，同时从另一个小门出。