A Manual D calculation is not required, but ductless projects still have to do calculations to determine the room-by-room loads based on specific features of the home and then calculations to determine how to size the distribution system to satisfy these loads. In the case where individual heating and cooling units are used in each room (e.g. radiant floor heating, mini-splits), the distribution requirement may be satisfied by performing the load calculations and then following manufacturer\'s guidance to meet these loads.