District Cooling System COP and Thermal Distribution Loss
Hi I am modelling building targeting LEED certification through eQUEST. The building itself is connected to a District Cooling System (DCS) with Ice Storage.According to "Treatment of district or campus thermal energy in LEED v2 & LEED 2009", a virtual plant can be modeled with some guided COP and thermal loss. While there are some questions I need to address.
a) The COP of cooling plant shall be 4.4 including cooling towers and primary pumps.
The COP4.4 sounds like a integrated COP value for the whole plant, not only for the chiller. But without the chiller type, pumps propeties, I have no idea how can I break it up and input into the energy model. I used to model the district cooling system based on actual design parameters. How can I then evaluate the plant COP? Divide the plant energy consumption by electricy used?
2) Input 5% thermal distribution loss for the District Cooling System.
What I understood is that the thermal distribution loss is mainly presented through the temperature change, can I simply enter 5% of design dT for the supply loss DT? or just multiplying 5% to the energy consumption by space cooling? Did I miss anything?
Any advice is much appreciated!