[Trace-users] TRACE LEED ENERGY MODEL-Modeling Water Cooled Unitary Systems With Single Outside Air System and Cooling Tower

[amit bhansali]

Hi All,
I am working on a LEED Energy model for a 8 floor Office Building. The
Baseline System type I have is Type 8 -VAV with PFP boxes / Chilled
Water-cooling, Electric Heating.

Now, the proposed building has Water cooling unitary units with a single
Outside Air unit. The outside air is supplied to mechanical room on each
floor through a ducted shaft with each floor having its own VAV box to
control the OA. Also, there is one single cooling tower that is used as a
Heat rejection equipment. I am doing this model in TRACE, so all the trace
experts are welcomed to answer this as well.

1. Since i have a Dedicated Outside Air Unit, I should model the outside
air fan for the baseline as well and allow it be sized based on PRM method
? Now, TRACE does not allow me to create a overall Air side system type
Outside air unit and thus i have to basically provide a Optional
Ventilation fan on each unit (i guess this is limitation but i cant think
of other way) for the Baseline.  Also, TRACE only allows 90.1 Fan power
adjustment to Primary fan (Supply fan) so i will not be able to take any
credit for fan power adjustment on Outside air fan for using better filters.
Similarly, for proposed building i have to model the Optional Ventilation
Fan but this would be based on my actual selection. The selection i have is
for Dedicated Outside Air fan. Is it safe to assume the proposed outside
air fan power in "KW/CFM" from the actual selection for the energy
consumption?

2. Similar to point 1, TRACE does not allow to create a single plant as a
heat rejection equipment for all the Indoor units. Thus, based on my
selection for cooling tower , condenser water pump, is it safe to simulate
the proposed building with cooling tower and pump for each water cooled
unitary system with the same KW/TON and Watts/GPM respectively?

Finally, if i can do the above mentioned things in simulation, does anyone
else have any experience with this kind of situation for the LEED model? I
can explain everything in Narrative (that these are limitations of Modeling
software) , however acceptance is based on who is reviewing this.

Any thoughts, suggestions are greatly appreciated.

-- 
Thanks

Sincerely,
Amit Bhansali, LEED Green Associate, M.S. , EIT
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/trace-users-onebuilding.org/attachments/20121129/4e2c9570/attachment.htm>