[Equest-users] Demand Direct Process Load
Nicholas Caton
ncaton at catonenergy.com
Mon Oct 12 15:24:26 PDT 2015
Y’know, I’ve long thought this is something we as a community could use a
illustrated reference/guide on. The recent ASHRAE energy simulation
conference in Atlanta fueled me with some community supporting spirit, so
let’s tackle that!
For those who have already figured out this puzzle: some elements are like
an onion, and you may not have uncovered all the layers (you too might find
this worth a read)! I’m going to do conclude with some ‘best practice’
advice for LEED model documentation. That’s sure to be different from
others smarter than myself, and it may prove helpful on the developers side
as well for further developing eQUEST’s capacity for aiding with LEED
reporting. I very much encourage discussion!
Let’s start with some extra context based on my understanding of the
“problem:”
Based on my personal exposure to GBCI review commentary over the past year
or so, the LEED reviewership body seems to have adopted a general policy of
“spot checking” various reported inputs by approximating “equivalent full
load hours” (also coined “FLE hours”). Essentially, the idea is by
dividing a given enduse’s annual consumption by the corresponding peak
demand (i.e. kWh/kW = h), you can get a sense of whether the associated
annual operations are nonsensical or else require further clarification.
>From a review perspective (or for internal QC & model development), this is
a fantastic “back-of-envelope” check to keep handy for evaluation of
results. I choose a word as strong as “fantastic,” because there are
precious few QC checks that can be performed so rapidly & directly within
the eQUEST user interface, without jumping into custom hourly and SIM
reports (the natural progression if this suggests symptoms of a bigger
issue).
In a perfect world, this sort of check would never lead to
misunderstandings. There are however a number of pitfalls on both the
reviewing and receiving ends that can lead to “false positives” for model
input problems, not the least of which is an incomplete/incorrect
understanding of the nuances between what the eQUEST interface (“rainbow”)
reports, SIM reports, and LEED CSV output reports are actually telling us
in terms of peak demands.
So here for consideration are a series of output screenshot excerpts I’ll
refer to for a single simulation run. I have cropped/isolated/highlighted
content to focus the discussion on a single end-use (space cooling). I
have also deliberately selected a LEED submission project for illustration
which isn’t the simplest case**, so that we can cover additional sides of
the issue you won’t encounter under every project:
· Monthly Peak Demand by Enduse (rainbow report):
[image: cid:image010.png at 01D0FF84.373831E0]
· The above rainbow report illustrates a situation where the annual
peak is not clear, due to automated rounding. 0.47 MW is indicated for
space cooling for both May and August. The ‘rainbow reports’ for
consumption/demand reference the same information written to an output file
whose name ends with “_EG_MoEU_ED.csv” in the project directory (*).
Following is an excerpt which comes from the corresponding CSV, and shows
the monthly maximum values before rounding. We can see more clearly the
highest monthly peak value for space cooling occurs in August:
[image: cid:image018.png at 01D0FF75.0CB59E30]
· Here is the PS-E SIM report for all Electric Meters – I’ve added
some annotations/highlighting for clarity:
[image: cid:image013.png at 01D0FF7D.8C829F70]
· The PS-F SIM report *for EM1*:
[image: cid:image017.png at 01D0FF7D.8C829F70]
· Finally, to complete the picture of probable misunderstandings,
let’s also consider the summary excerpt from the current File à Export File
à LEED Results (CSV)… feature:
[image: cid:image024.png at 01D0FF6D.BB1ECB20]
So with these visuals handy, let’s summarize the figures in front of us:
1. Rainbow reports: maximum demand value for ‘space cooling’ = *472.167
kW, occurring in the month of August*.
2. PS-E report: annual “MAX KW” is *474.025 kW, in June*
3. PS-E report: annual “PEAK ENDUSE” = *460.149 kW, in June*.
4. PS-F for EM1: annual “MAX KW” = *474.025 kW, in June.*
5. PS-F for EM1: annual “PEAK ENDUSE” = *471.084 kW, in June*.
6. LEED CSV output: *471.084 kW, (unspecified time)*.
CLEARLY… the water is muddy so far. For those keeping score, I have *4*
different values to differentiate here.
In order of largest to smallest:
§ *474.025 kW:* PS-E and PS-F (for EM1) agree on this “MAX KW” value for
space cooling. This is the highest draw for ‘space cooling,’ independent
of meters & coincident peak draw hours for the entire year:
“Non-coincident enduse peak.”
§ *472.167 kW:* This maximum peak demand from the ‘rainbow report’ is the
contribution of ‘space cooling’ at the hour of highest electrical draw in
the month of August, *for all electric meters*. This is the demand at the
“coincident peak” for the year.
§ *471.084 kW:* As confirmed with the developers (thanks!), the LEED CSV
output feature by design sums the annual “PEAK ENDUSE” (read “annual
coincident-peak”) outputs for all PS-F reports to come up with
“Baseline/Proposed Design Demand” outputs. These sum results can in turn
come from a variety of different peak hours during the simulation (those
for each meter), and therefore do not cleanly fit the definitions of “MAX
KW” or “PEAK ENDUSE.” In this case, we are seeing the contributions of
space cooling during the annual peak coincident hour *as seen by meter EM1
in isolation*. That this value differs from the ‘rainbow report’ maximum
value is because the loads on non-EM1 meters are shifting the coincident
peak hour for the whole building away from what the loads under EM1 alone
would suggest*. (An aside: I promise, I’ve proofed this passage a few
times and am struggling to convey this more clearly!)*
§ *460.149 kW:* This is what ‘space cooling’ contributes to the
coincident-peak consumption for the year, *for all electric meters*. This
is distinct from and lower than the maximum rainbow report value, because
the annual building peak occurs in the month of June instead of August.
Suggested “Best Practices” for LEED documentation (TLDR!):
· *When you have only the default utility meters EM1 and FM1*: The
annual “MAX KW” / “MAX MBTU/HR” values found at the bottom of the PS-E
reports are the most representative/intuitive quantities in consideration
of how they are leveraged in LEED model reviews for “equivalent full load
hours.” They represent the maximum “non-coincident peak” for each enduse,
for the whole project. For preliminary submission, use those for reporting
simulation enduse demand, and include at least the PS-E reports in the
collection of SIM reports you elect to upload for supporting
documentation. BE AWARE these values do not match the “coincident peaks”
visualized with the rainbow reports.
· *When you have more than one of any type of meter (commonly to
distinguish and separately document loads that would otherwise fall under
the same enduse category):* Refer instead the “MAX KW” / “MAX MBTU/HR”
annual values found at the bottom of the PS-F reports for each meter, and
include all PS-F reports in your supporting documentation. Recognize the
peak non-coincident enduses for the master meters (EM1/FM1) may require
some addition/subtraction of the other meters’ peaks if you elected to
define the additional meters on a different level (i.e. submeters instead
of utility).
· If you elect to include any of the “rainbow reports” in
supporting LEED documentation, be mindful these are all built upon
“coincident peaks” of one form or another, and do NOT represent
“non-coincident” or “independent” maximum draws for each enduse. I for one
have gravitated *away* from providing any of these graphical reports, as
they seem to be a common source for misunderstanding/confusion when a
reviewer is looking for documentation issues. If I have to explain *one
more time* why there isn’t any exterior lighting demand during the monthly
coincident peak hours…. =)
· DO recognize this sort of “full load equivalent hours”
check/approximation is very easy to perform and can save you time in
review/QC of simulated models, directly from the eQUEST user interface.
· Also recognize NONE of these peak/demand outputs can be counted
on as equivalent to “installed capacity,” which is what a GBCI reviewer is
generally looking for to approximate “full load equivalent hours.”
o Some common causes for this divergence include:
§ Any fractional schedules for loads which do not hit 100% (including
every ASHRAE-recommended fractional schedule for every occupancy type,
excepting parking garages),
§ All oversizing factors for system heating/cooling capacities (i.e. every
correctly autosized 90.1 baseline system, ever),
§ and the variety of operational inputs concerning systems’ behavior will
cause enduse demand figures of all stripes to diverge from “installed
capacity.”
o Reviewers and diligent modelers interesting in QC’ing their efforts
alike are encouraged to “dive deeper” and seek more case-specific
inputs/outputs to ensure operating hours are within reason, when such an
approximation causes raised eyebrows.
Wishing everyone the best,
~Nick
* An interesting footnote: As it stands uncorrected, I believe
“_EG_MoEU_ED.csv” stands for “*E*very *G*ood *Mo*deler *E*ducates the
*U*niformed
*E*ach *D*ay,” as proposed by Mr. Bill Bishop earlier this year over these
mailing lists.
** In hindsight, there are a few other possible pitfalls in demand
reporting I didn’t hit with this example, which would fall under the
category of “best practices for metering structure…” (a writeup for another
day!) For now I’ll just say to be extra mindful with your meters when you
are simulating any on-site power generation, cogeneration, tri-generation,
and specific cases for district heating/cooling networks.
*NICK CATON, P.E.*
*Owner*
*Caton Energy Consulting*
306 N Ferrel
Olathe, KS 66061
office: 785.410.3317
www.catonenergy.com
*From:* Equest-users [mailto:equest-users-bounces at lists.onebuilding.org
<equest-users-bounces at lists.onebuilding.org>] *On Behalf Of *Eric Fischel J.
*Sent:* Friday, October 02, 2015 3:43 PM
*To:* Brian Fountain; equest-users at lists.onebuilding.org
*Subject:* Re: [Equest-users] Demand Direct Process Load
Hello Brian, that right there is a shift in the moment of the peak demand.
Does anyone know how to resolve this in the model or in any case how to
deal with it in the LEED submittal for the reviewrs no to coment on it?
I have done lots o models and never came acorss with this issiue previsuly.
Best regards.
* Ing. Eric Fischel J. *
Tel.: (506) 2222-7529
Fax: (506) 2256-5608
From USA: 1-305-433-3668
Calle 30, Avenida 0 y 2. San José, Costa Rica
[image: Logo CTS firma] *[image: Description: LEEDAP_BDCbw]*
*Este correo puede contener información protegida por el secreto
profesional. Si usted no es la persona a quien va dirigido, por favor tome
en cuenta que su divulgación, distribución o reproducción es estrictamente
prohibida. Cualquier persona que reciba este mensaje por error debe
notificarlo inmediatamente al remitente vía telefónica o correo electrónico
y borrarlo permanentemente de su computador. Los comentarios plasmados en
este correo son del remitente solamente y no reflejan necesariamente la
posición de CTS S.A.*
*Por favor considere su responsabilidad con el medio ambiente antes de
imprimir este correo electrónico*
*----------------------------------------------------------------------------------------------------------------*
*This mail may contain information that is legally privileged, confidential
or exempt from disclosure. If you are not the intended recipient, please
note that any dissemination, distribution or copying of this message is
strictly prohibited. Anyone who receives this message in error should
notify the sender immediately by telephone or by e-mail and delete it
permanently from their computer. The opinions above are those of the
author and do not necessarily reflect the position of CTS S.A.*
*Please consider your environmental responsibility before printing this
e-mail *
*From:* Brian Fountain [mailto:bfountain at greensim.com
<bfountain at greensim.com>]
*Sent:* Thursday, October 01, 2015 1:43 PM
*To:* equest-users at lists.onebuilding.org; Eric Fischel J. <
eric.fischel at cts-cr.com>
*Subject:* Re: [Equest-users] Demand Direct Process Load
I would look at your PS-E report to see when the peak loads are occurring
in your proposed and baseline models. I suspect that the slight shift in
when the peak demand is being set changes the breakdown of that peak demand.
On 01/10/2015 2:18 PM, Eric Fischel J. wrote:
Hello David, thanks for the tip on the process loads.
In the following table the results show that the KWh for the receptacle
equipment is the same but we get -15.4029 in demand saving. (We triple
check schedules and w/sf they are exactly the same)
Additionally we use the “Exterior Usage” and “Task Lighting” categories in
the Electric Meter Direct loads ( for water pump, elevator, exterior
lighting), using the same Schedule and Load (KW). As you can see the show
saving in Demand.
What would we change In the *.SIM file to get the same results in the
process load?
Thanks again for your help!
* Ing. Eric Fischel J. *
Tel.: (506) 2222-7529
Fax: (506) 2256-5608
From USA: 1-305-433-3668
Calle 30, Avenida 0 y 2. San José, Costa Rica
[image: Logo CTS firma] *[image: Description: LEEDAP_BDCbw]*
*Este correo puede contener información protegida por el secreto
profesional. Si usted no es la persona a quien va dirigido, por favor tome
en cuenta que su divulgación, distribución o reproducción es estrictamente
prohibida. Cualquier persona que reciba este mensaje por error debe
notificarlo inmediatamente al remitente vía telefónica o correo electrónico
y borrarlo permanentemente de su computador. Los comentarios plasmados en
este correo son del remitente solamente y no reflejan necesariamente la
posición de CTS S.A.*
*Por favor considere su responsabilidad con el medio ambiente antes de
imprimir este correo electrónico*
*----------------------------------------------------------------------------------------------------------------*
*This mail may contain information that is legally privileged, confidential
or exempt from disclosure. If you are not the intended recipient, please
note that any dissemination, distribution or copying of this message is
strictly prohibited. Anyone who receives this message in error should
notify the sender immediately by telephone or by e-mail and delete it
permanently from their computer. The opinions above are those of the
author and do not necessarily reflect the position of CTS S.A.*
*Please consider your environmental responsibility before printing this
e-mail *
*From:* David Eldridge [mailto:DEldridge at grummanbutkus.com
<DEldridge at grummanbutkus.com>]
*Sent:* Tuesday, September 22, 2015 8:51 AM
*To:* Juan Carlos Sanabria F. <juan.sanabria at cts-cr.com>
<juan.sanabria at cts-cr.com>; equest-users at lists.onebuilding.org
*Subject:* Re: [Equest-users] Demand Direct Process Load
Double check the timing of the peaks – the graphical presentation in eQUEST
is the coincident peak – the contribution of each component at the time
that the building hits its total highest demand.
It’s likely that the proposed building has a peak later in the day due to
one or more efficiency measures that are included. If the process loads are
lower at this time, the graphical presentation will show that the peak
component is less than the baseline case. (Or if the process ramps up later
in the day, it could be more?)
You’ll need to go into the *.SIM file to get the reported peaks for the
process loads (and show the annual totals to also be the same) to
demonstrate that the schedules are consistent, or otherwise explain to the
reviewer what is happening.
David
David S. Eldridge, Jr., P.E., LEED AP BD+C, BEMP, BEAP, HBDP
*Grumman/Butkus Associates*
*From:* Equest-users [mailto:equest-users-bounces at lists.onebuilding.org
<equest-users-bounces at lists.onebuilding.org>] *On Behalf Of *Juan Carlos
Sanabria F.
*Sent:* Monday, September 21, 2015 6:10 PM
*To:* equest-users at lists.onebuilding.org
*Subject:* [Equest-users] Demand Direct Process Load
Hi,
I’m modeling a building for LEED, but when I go to equest LEED report I
notice that my direct process load for demand is not equal, anyone know why
this happen?
I review the rate and the schedules and are the same also the energy load
is the same for the proposed and the baseline.
Thanks,
* Ing. Juan Carlos Sanabria F. *
Tel.: (506) 2256-7020
Fax: (506) 2256-5608
From USA: 1-305-433-3668
Calle 30, Avenida 0 y 2. San José, Costa Rica
[image: Logo CTS firma]
*Este correo puede contener información protegida por el secreto
profesional. Si usted no es la persona a quien va dirigido, por favor tome
en cuenta que su divulgación, distribución o reproducción es estrictamente
prohibida. Cualquier persona que reciba este mensaje por error debe
notificarlo inmediatamente al remitente vía telefónica o correo electrónico
y borrarlo permanentemente de su computador. Los comentarios plasmados en
este correo son del remitente solamente y no reflejan necesariamente la
posición de CTS S.A.*
*Por favor considere su responsabilidad con el medio ambiente antes de
imprimir este correo electrónico*
*----------------------------------------------------------------------------------------------------------------*
*This mail may contain information that is legally privileged, confidential
or exempt from disclosure. If you are not the intended recipient, please
note that any dissemination, distribution or copying of this message is
strictly prohibited. Anyone who receives this message in error should
notify the sender immediately by telephone or by e-mail and delete it
permanently from their computer. The opinions above are those of the
author and do not necessarily reflect the position of CTS S.A.*
*Please consider your environmental responsibility before printing this
e-mail *
_______________________________________________
Equest-users mailing list
http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org
To unsubscribe from this mailing list send a blank message to
EQUEST-USERS-UNSUBSCRIBE at ONEBUILDING.ORG
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20151012/7203c10f/attachment-0002.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image001.jpg
Type: image/jpeg
Size: 5450 bytes
Desc: not available
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20151012/7203c10f/attachment-0014.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image002.jpg
Type: image/jpeg
Size: 3228 bytes
Desc: not available
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20151012/7203c10f/attachment-0015.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image003.jpg
Type: image/jpeg
Size: 2943 bytes
Desc: not available
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20151012/7203c10f/attachment-0016.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image004.png
Type: image/png
Size: 29472 bytes
Desc: not available
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20151012/7203c10f/attachment-0014.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image005.png
Type: image/png
Size: 39439 bytes
Desc: not available
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20151012/7203c10f/attachment-0015.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image006.jpg
Type: image/jpeg
Size: 5920 bytes
Desc: not available
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20151012/7203c10f/attachment-0017.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image007.jpg
Type: image/jpeg
Size: 3423 bytes
Desc: not available
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20151012/7203c10f/attachment-0018.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image008.jpg
Type: image/jpeg
Size: 3142 bytes
Desc: not available
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20151012/7203c10f/attachment-0019.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image009.jpg
Type: image/jpeg
Size: 5449 bytes
Desc: not available
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20151012/7203c10f/attachment-0020.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image010.png
Type: image/png
Size: 102689 bytes
Desc: not available
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20151012/7203c10f/attachment-0016.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image011.png
Type: image/png
Size: 6501 bytes
Desc: not available
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20151012/7203c10f/attachment-0017.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image012.png
Type: image/png
Size: 454513 bytes
Desc: not available
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20151012/7203c10f/attachment-0018.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image013.png
Type: image/png
Size: 378941 bytes
Desc: not available
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20151012/7203c10f/attachment-0019.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image014.png
Type: image/png
Size: 16952 bytes
Desc: not available
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20151012/7203c10f/attachment-0020.png>
More information about the Equest-users
mailing list