Dear All,

I'm now working on a project using Districted Heating System provided by
a municipal system. The municipal system is working for a very large
areas providing steam for about hundred buildings. And my building is
one of them.

According to the latest update issued by USGBC
(https://www.usgbc.org/ShowFile.aspx?DocumentID=4176), the modeling will
be implemented by two steps. My question is about Step-2 (Aggregate
Building/DES Scenario). In step-2, the energy source of Proposed
Building is virtual on-site chiller representing upstream DC system. The
document also issues "The DES central plant itself shall always be
modeled as a total, entire unit." My understanding is that it requires
to model the central plant with the full capacity that is able to
provide heating for all of buildings in whole district. However, if
doing so, the energy consumption of the proposed building may be quite
quite high, since it includes the energy consumption of the whole
heating plant!! But my building is only one of the 100 buildings that
are heated by the central plant. It is weird and I don't think it is
what USGBC asked for. Does anyone know what shall I do for the proposed
building in Step-2?

Thank you.

May Xu, LEED(r)AP