I'd like to get some feedback on my case regarding district Thermal
Energy. I've had conflicting responses on the subject and have found no
definitive answer.
The baseline system qualifies to be modeled as System type 2 (PTHP). The
proposed system uses district chilled water only and no central heating
plant. According to table 3, in the Required Treatment of District
Thermal Energy... document, Systems 1&2 are to be modeled as constant
volume fan coil units with hot water fossil fuel boilers. My proposed
system uses all electric heating coils. How is this cost-neutral
modeling?
Should I stay consistent with my proposed design and model the baseline
as constant volume fan coil with electric heating coils, or should I
model the baseline as constant volume fan coil with hot water electric
boilers?
Thanks, in advanced for any responses.
Jason Siensa
Hi Jason,
For Step 1, you should model it as indicated in the District Energy
Requirements document with hot water fossil fuel boilers. Your Step 2
model would reflect PTHP systems.
Best Regards,
Gail Hampsmire
Jason,
I have a situation that is identical to the one you describe. Modeling
the baseline in step 1 with gas, although as you say it may not seem
inline with the idea of cost-neutral modeling, it is specifically what
the document requires. That is the way I have proceeded. Good luck!
Regards,
Jonathan M. Curtin, EIT, LEED(r) AP
Friends,
We have a central plant serving an existing building and an renovated building
in Washington, DC . We are applying for LEED-NC for the
renovated building. We are required to follow the ?Required treatment of
District thermal energy in LEED-NC version 2.2? method for our EAc1
credits.
Does anyone have an advice on what utility rates can be used for
chilled/hot water. Although we have a source for district steam rates I am not able find chilled water rates. The eia.doe.gov site does not seem to provide the rates either.. Also, I am not sure if
we are justified in using commercial rates which can be significantly
higher as they include delivery and service charges.. The rates used can have a significant impact on the total savings as they determine
the proportion of electricity and chilled/hot water costs.
thanks for your responses,
raj