The DES guideline (2010) allows us to model DES cooling plant with a COP of 4.4, which includes cooling towers and primary pumps. When we use this default efficiency, can we still apply a part-load curve? (something like 90.1 default curve) Or is it an average efficiency which already count for all part-load and full-load condition? (in which case we need to apply a flat curve to the cooling plant) Thanks.