How to choose the fan coil unit with right cooling capacity

When we dsign a villa for ourselves the cooling and heating system is neccessary, because which can enssure us live in a very comfortable life. And the water chilled system for cooling and heating is a good choice. Then how to choose the right cooling capacity of the fan coil unit? Gnerally, we have different standard according to different fuanction. But now we are talking about the villa, so the standard is about 100w/㎡. For example: if you have a room size 4*4m, 16 sqaure meters, then this room need about 1.6kw cooling cpacity.And your the cooling cpacity equal to all the fan coil unit total cooling capacity.