French window and large window are very popular in modern house design. We can get good view through French window or large window. The window is one of main entries of air. So the window also helps you to get fresh air and sunshine. But if the window is too large, it will destroy the harmony in your bedroom according to the feng shui rules.
As you know, People have some unseen energy filed. People will relax during having rest or sleeping. At that time the energy will lose easily, so the immunity will become very weak. (That is why; we often catch cold or headache during sleeping).The bedroom shall be comfortable for sleeping and helpful to keep our energy. The size of bedroom and the window are the key factors to keep our energy. (Last time, we had discussed the ideal bedroom sizes per feng shui). The large window or French window does not help us to keep energy when we sleeping. The seal of window is not like as wall, so there must be some cold air and energy chi flow into your bedroom during nighttime, so your energy will be absorbed. In long term, energy loss will cause many health issues.
The large window also will cause unstable feng shui energy in your bedroom.
If you really do love large window or french window, pls remember to hang thick curtain to reduce the influence.
Of course too small window will not be good to refresh the air or feng shui energy and get enough sunshine.