eQUEST: Hours outside throttling range for Standard VAV w/Reheat

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All,

I am modeling a "Standard VAV w/Reheat" for a small college building
(~20,000 SF) and am having some difficulty reducing my hours outside of
throttling range. I have tried increasing my "Throttling Range" to 4 F,
increasing my system size capacity (from 1.15 to 2), and have also
adjusted my "Heat Temp Schedule" to turn all but one zone to default to
create a 'control zone' for the system. However, I still have many
unmet hours (~39% of hours outside of throttling range - my BEPU report
does not identify hours, but rather a % (reference previous Equest
thread)).

Any suggestions are certainly welcome!

Thanks in advance,

Gordon

Gordon D. Schweitzer's picture
Joined: 2011-09-30
Reputation: 0

Gordon, go to the SS-F reports for each zone in your DOE2 output, here you
will be able to identify which zones suffer from underconditioning and
whether it is heating or cooling energy that is insufficient. If it is
heating energy (i.e. underheated) which is my guess for your model then you
can adjust items to offer more heating energy. You might want to install
baseboards in your system & zones, you may need to adjust your reheat coil
delta T, or something else.

You can always send us your .pd2 & .inp files so that we can open up your
project, review it and give you some suggestions.

pasha

Pasha Korber-Gonzalez's picture
Joined: 2011-09-30
Reputation: 400

Thanks Pasha. I originally included a zipped folder, but it may have
been too big (~2MB). Please see attached.

Gordon D. Schweitzer III, LEED AP BD+C

Gordon D. Schweitzer's picture
Joined: 2011-09-30
Reputation: 0

Gordon:

Try increasing the throttling range to 6 DegF. Also find out WHEN your unmet hours exist by looking at SS-O reports, which show 8760 of space temperatures based on time of day.? If I get a chance later today,?I will look at your run.

John R. Aulbach, PE, CEM

John Aulbach's picture
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Joined: 2011-09-30
Reputation: 1

Gordon,
Your roof u-value is defined as 34.28. Note that the user-defined value
is not the R-value, which is probably what you were
trying to define? Please edit to reflect the correct u-value. Maybe this
will help some.

Umesh Atre's picture
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Joined: 2011-09-30
Reputation: 0

Thanks Umesh - However, I do believe that in the "Layer by Layer"
Construction tab the unit is R-Value, as opposed to the U-value. Thank
you for double checking though, as that is a critical piece of
information.

Gordon D. Schweitzer III, LEED AP BD+C

Gordon D. Schweitzer's picture
Joined: 2011-09-30
Reputation: 0