i'm an Architecture Engineer with no experience with HVAC design. i read in previous questions about the use of ideal air loads system and it was quite helpful to give me a sense of the heating/ cooling loads according to different architectural features, but there is something i need to understand here about the configuration of the system. is it based on a central system or an individual system and if individual how can i tell the input and output units used for the room and if it's central how can i tell how many air handling unit in every room ? thanks