[Bldg-sim] LEED modeling and zone adjacencies...

[James V. Dirkes II, PE]

I vote:  Assume all spaces are the same setpoint and temp for a LEED
analysis unless there will be actual, significant differences in the real
building
 
a) The simulation tool is assuming that the HVAC is trying to do exactly
that
b) Your weather file is an approximation (TMY)
c) You have no idea what the actual thermostats will be set for
d) the simulation will not model the actual control system response
e) LEED has accepted our models with that assumption, which I think is
appropriate based on the above reasons and a variety of others.  There's
only so much you can expect from a model of a yet-to-be-constructed
facility!
 

The Building Performance Team
James V. Dirkes II, P.E., LEED AP
1631 Acacia Drive NW
Grand Rapids, MI 49504
616 450 8653

 

 


  _____  

From: bldg-sim-bounces at lists.onebuilding.org
[mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Cramer
Silkworth
Sent: Monday, July 27, 2009 1:23 PM
To: bldg-sim at lists.onebuilding.org
Subject: [Bldg-sim] LEED modeling and zone adjacencies...


Hi all,

I'm building a model (in TRNSYS) for LEED, and I'm trying to figure out how
detailed I need to be with my zone adjacencies. TRNSYS can do very detailed
accounting for how a zone's walls (+floors, ceilings) interact with other
zones. However, for conditioned spaces, the heat transfer is zero when the
spaces are the maintained at same temperature. My life would be a lot easier
if I could just say that the temperature on the outside of each wall was
equal to the temp setpoint, or perhaps the temp of the largest neighboring
zone, rather than do a detailed description of all interzonal adjacencies.
90.1 and The LEED Ref Guide don't seem to say anything about this. So, I'm
wondering, based on your knowledge of whatever program you use, how detailed
to I need to be? Do eQuest, Trace, energy Plus, etc, do detailed adjacency
calcs or just assume a boundary temperature?

Thanks,
Cramer

-- 
J. Cramer Silkworth
Transsolar Climate Engineering
Technical consulting for energy efficiency and environmental quality in
buildings.
134 Spring Street, Suite 601
New York, NY 10012
212-219-2255
silkworth at transsolar.com 

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