[Equest-users] Revert efficiencies to autosize from detailed?

[Nathan Miller]

Laura, 

 

Many questions here, so I will try to respond succinctly to each, but
forgive me if I am a little short on details. 

 

1)      eQUEST WILL NOT default to the proper 90.1 baseline efficiency or
fan power for your systems. You need to look up the appropriate EER (or
COP, or whatever) and convert it to the proper EIR (unitless) efficiency
to input in eQUEST. However, to further complicate things, if the 90.1
baseline efficiency includes system fan-power, you need to separate out
that fanpower from the EIR rating and input the fanpower separately. There
has been much discussion of this even in the past week on the forums, so I
recommend doing some searches for "separating fan power" or the like. 

2)      Yes, use the defined 90.1 Appendix G baseline even if local code
is more stringent. Consider it a nice little bonus of working on projects
with strict energy codes. 

3)      System 4 (PSZ-HP) should have constant volume fans. You are taking
a penalty if they were made variable speed in the baseline. 

4)      You can edit the project name by opening the .inp file in a text
editor, and changing the "Title" field. Then save the .inp, reopen in
eQUEST and it should be good to go. 



 

Nathan Miller, PE, LEED AP BD+C

Mechanical Engineer/Senior Energy Analyst

O 206-285-7100 | D 206-788-4577

 <http://www.rushingco.com/> www.rushingco.com

 

From: equest-users-bounces at lists.onebuilding.org
[mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Laura
Howe, RCE
Sent: Tuesday, June 12, 2012 1:11 PM
To: equest-users at lists.onebuilding.org
Subject: [Equest-users] Revert efficiencies to autosize from detailed?

 

HI All-

 

While there are some posts similar to this issue, I want to ask the group
for clarification for a slightly different application.  Please bear with
me for some assistance, I'd sure appreciate it!

 

I am working on someone else's model that has had comments back from GBCI
for a LEED project. The model came to me in detailed mode.  They note that
in the baseline model apparently non-90.1 baseline efficiencies were used.
Looking at the model, it does seem that the modeler manually entered
efficiencies (they are in red) and they do not seem to be correct (even
the GBCI comment notes this).  They are less efficient than 90.1. In some
of the similar threads on this topic, someone mentioned that you can
revert to autosizing by right clicking on the heating and cooling capacity
and selecting "restore default".  Since the modeler did not manually input
system size, just system efficiency (both cooling and heating hp eff, fan
design kw/cfm and total eff frac seem to be manually entered), my question
is if I restore those efficiency values to default (using right clicking),
will Equest use the proper efficiencies and I'm good to ho?  I've done
this, and it seems to work, although I'm not experienced enough to truly
verify this.  

 

When I compare the two models (original base and my reverted base) I do
see where the power demand has dropped (SV-A), and none of the peak loads
have changed (LS-A) but the equipment sizing (SV-A) has increased.  This
all seems correct, do others think I am on track here?  Using the correct
methodology?

 

If I can also confirm another question, LEED specific.  I understand 90.1
is the only appropriate base case for LEED even in Washington state, even
if portions of their energy code are more stringent, correct?  The
requirement to achieve a 10% reduction is how I think LEED addresses more
stringent state codes so the base doesn't need to be written specific to
those (numerous) state codes.  Correct? One comment from the client leads
me to think that complying with WA code might explain the difference in
equipment efficiencies used in the base case, and even though it doesn't
add up I want to confirm my understanding.

 

Another issue that further confuses this is that the modeler apparently
chose two of the systems to be variable speed (all are system type 4,
constant volume in 90.1) and I'm not sure why.  The original modeler is
not available for questioning.  Any ideas?  The VFD's were applied to an
office space and data/server room packaged heat pumps, but not a large
storage space.  Based on what I know right now, it seems those should be
modeled constant volume.  If I'm updating the base model, I think it makes
sense to correct this if the base incorrectly models a more efficient
system.

 

Lastly, can anyone tell me how to change the project descriptor at the top
left of the sim reports?  It's got some boilerplate name and it sure would
be nice to have the filename show, or at least a single descriptor I can
update in each model run.

 

Thanks so much-

Laura

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