Hi

I am currently in a project in which I have to design an AC unit, and since I am pretty new to this whole world (I am in my practical placement as an engineer), I have some questions regarding the choosing of components.
When choosing the evaporater and the condenser, which elements influence the choice, as I understand it you have to choose it from the needed capacity, but almost everyone i look at is overdimensioned by a lot?
How do you calculate what the necessary heating exchange area should be?
Lastly, can you recommend any good suppliers of evap. and cond. coils?

Kind regards

Michell