Hi All!

I am doing energy model for EA 1.3 LEED 3.0 CI. My project takes 2 floors of
8 story building. I am trying to understand this credit, and I probably
think to hard and make everything to difficult.

The building is LEED certified already. Energy model was done by AHSRAE
90.1-2004. All floors have WSHP units that cool and heat spaces. Fresh air
is delivered by energy recovery rooftop unit. System includes 2 boilers,
pumps, and 2 closed circuit evaporative cooling towers.
I'm working in Trace program.
So my project has common ERU, heating and cooling plants with other floors.
The underfloor air distribution system and two heat pumps were added to in
my project + occupancy sensors.
Could you explain me please, how do I need to build my model.
1. Do I have to model the whole building or take the area within my project
?
2. I will have 3 alternatives as it is required in LEED CI EA1.3 . First is
my actual design, third is a model by AHSRAE 90.1 2007. I can't understand
what should include the second alternative ( baseline case step 6 ) in this
case if I take area only within my project. Does it have to be my actual
design before renovation?

Please, help me to understand and to get clear thoughts.

Thank you

--
With best wishes,
Genia