Hello, All

I got a question about energy simulation for LEED CI. Would you please help to clarify it?

I am doing the energy simulation for a project pursing CI, which is in a 20-floor-height building. The whole building is served by one HVAC system, and the chilled water system is primary/secondary systems with variable-speed drives on the secondary pumping loop. Energy cost budget method is used to determine the budget case, which will be system type 1 (chilled water for cooling). In ASHRAE90.1-2004, it is said that 'Pump system power for each pumping system shall be the same as the proposed design; if the proposed design has no chilled water pumps, the budget building design pump power shall be 349 kW/1000 L/s . The chilled water system shall be modeled as primary-only variable flow with flow maintained at the design rate through each chiller using a bypass.' (page 75). I am confused here. In budget case of my project, shall the chilled water system be primary/secondary systems as proposed case, or be primary-only system?

Thanks & Best Regards,

Han Lin