[Equest-users] Team eQUEST: Lowdown Showdown Report

[Nicholas Caton]

While Chris Jones actually performed the SPOT analysis for our team, I
think I can tackle #2 concerning the decision to move the daylighting
analysis outside of eQUEST/DOE-2.



The decision to “go beyond” the baked in capabilities of eQUEST concerning
the daylight was motivated by a number of factors:



-          Interest within the team individuals to pick up some more
advanced daylighting analysis experience in a ‘safe/constructive’
environment.

-          “Coincident Timing:”  SPOT (sensor placement and optimization
tool) came about with an update that allows one to tackle full LEED v4
calculations while we were in the middle of project development.  At the
time (and perhaps even now), SPOT was/is the ONLY tool which could actually
perform all required aspects for the LM-83-12 ASE and sDA annual
daylighting simulations.  Combine that with the fact that I and others on
the lowdown team had clientele actively pursuing LEED v4… and you have the
perfect storm!

-          One thing such an external analysis will allow you to do in a
design setting is provide informed/constructive feedback to the
envelope/fenestration designers “beyond WWR.”  In our project, we started
out with the typical “band” of windows on each façade as automated by the
wizards, and through our external daylighting analysis we found that if we
kept the same overall WWR we could mitigate the resulting glare issues by
both breaking up the windows along each façade and with select application
of diffusing blinds for specific exposures.



Relative accuracy of the eQUEST/DOE2 platform for daylighting was probably
never a major motivating factor for any of the individuals on the team.
>From my personal experience however, I can make some comments on the
matter.  Though we can in hindsight assert the external analysis resulted
in a substantial reduction for simulated lighting energy, relative to the
“high level” simulation directly within eQUEST, I do not believe this
result in isolation is indicative of a problematic trend. The inputs and
defaults/setup-automation available to approximate daylighting controls
with eQUEST are together in many ways a rough approximation, and for many
cases that’s quite appropriate.  This is not intended as a knock on the
tool: as with other building energy simulation engines/platforms, many of
the important (but ultimately quite time-consuming) nuances of what goes
into how daylight actually interacts with a given lighting system in a
given space over time in a specific microclimate are generally lost.  There
is still substantial value however in quickly-performable approximations
for behavior of such systems.



For what it’s worth, it has been my general observation that for typical
‘open office’ perimeter daylighting zone cases, my eQUEST/DOE2 simulations
(leveraging library defaults and not leveraging the optional ‘sensor
obstruction inputs’ generally err on the **conservative** side with respect
to annual electricity savings for daylighting ECM’s (which is to say I
would generally expect a well-designed/specified/installed daylighting
control system to save more energy than a typical eQUEST effort would
approximate).



I cannot place where eQUEST/DOE-2 sits on this ‘conservative/aggressive’
scale when you begin to introduce the likes of automated blinds/diffusers.
Most of my efforts working such measures into eQUEST ultimately feel like
“hacks” in some fashion, so I can’t be terribly certain I’m comparing
apples to apples when I consider the annual results against those of an
external study.



Hope that helps!



~Nick





*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] *On
Behalf Of *Aaron Powers
*Sent:* Thursday, November 12, 2015 9:03 AM
*To:* equest-users at lists.onebuilding.org; Joe Huang <
yjhuang at whiteboxtechnologies.com>
*Subject:* [Equest-users] Team eQUEST: Lowdown Showdown Report



Joe,

I think I can answer a few of your questions.

1. Almost everything was modeled out of the box, with the exception of the
passive down-draft system as you mentioned.  Our method for modeling this
system was:

    - Model the systems as 100% outside air VAV.

    - Create an hourly report for each system on the cfm required to meet
space conditions

    - Using the Sherman-Grimsrud algorithm, we calculated the maximum
available wind+buoyancy driven flow on an hourly basis(may be a stretch on
the intent of the algorithm)

    - Comparing the maximum available to the hourly requirements, we found
that we would not need mechanical ventilation for about 85% of the year.
This was fed back into the eQuest model as a global parameter to derate the
supply fan kW accordingly.

This method was a bit of a hack to get the building modeled before the
deadline, so I'm sure the more creative individuals on the list can think
of a better method.  I believe the DOE2 engine is very close to being able
to model this out of the box.  The S-G algorithm is already available for
natural ventilation, but it is not automatically controllable as would be
our case with automatic dampers.  In a real project, CFD would probably be
used for design but would be overkill for an hourly/subhourly simulation.
I believe that an empirically based model which can capture the
wind+buoyancy effects like S-G is ultimately the way to go for an annual
simulation.

3. The 3D plot shows the building consumption on the z axis vs the window
to wall ratio and shading coefficient on the x and y axes.  We chose these
because they are two of the more interactive variables in the design.  I
completely agree about the runtime. I believe that scientific inquiry
always goes in two directions: either to answer problems on a massive scale
or to answer problems on the microscopic scale (e.g. the discovery of black
holes and the electron in the 20th century).  It seems that the building
simulation community has fully embraced the challenge of the microscopic
problem by adding more and more detail to models and simulation programs
but has not fully embraced the challenge of the large scale problem.  This
is where I think that "legacy" tools like DOE2 can play a huge role since
we don't shy away from large problems due to a long run time or long model
creation time.

Aaron


---------- Forwarded message ----------
From: Joe Huang <yjhuang at whiteboxtechnologies.com>
To: equest-users at lists.onebuilding.org
Cc:
Date: Wed, 11 Nov 2015 07:46:32 -0800
Subject: Re: [Equest-users] Team eQUEST: Lowdown Showdown Report
Nick, Aaron, Cara, Pasha, Chris,

I'd like to add my congratulations to those of others for your great work
at the Lowdown Showdown.  It's very impressive what your team was able to
achieve on a strictly voluntary basis, and shows how much innovative
modeling can be done with eQUEST/DOE-2 .

For my personal curiosity, I'd like to ask the team:
(1) how much of your work was done using eQUEST "out of the box", and how
much of it tweaking the underlying DOE-2.2 engine? This question applies
mostly to the modeling of low-energy HVAC strategies, esp. the solar
chimneys.
(2) what was the motivation to use Radiance to calculate daylighting
instead of the native daylighting capabilities in DOE-2?  (this is not
meant as a challenge - I simply have never looked into the
strengths/weaknesses of the DOE-2 daylighting calculation)
(3) great to see the multi-variant analysis of 60,000 runs, especially the
colorful 3-D surface plot :-)   What were the two axes being plotted?
There are those who dismiss slow runtimes as just an annoyance, but my
experience is that fast runtimes open up whole new ways of analysis.  When
DOE-2 runtimes got down to a few seconds, I started doing a lot more
experimental design.

I also suggest that you send your post to BLDG-SIM to get more
distribution, especially among readers less familiar with eQUEST.

Once again, congrats!

Joe

Joe Huang

White Box Technologies, Inc.

346 Rheem Blvd., Suite 205A

Moraga CA 94556

yjhuang at whiteboxtechnologies.com

http://weather.whiteboxtechnologies.com for simulation-ready weather data

http://www.whiteboxtechnologies.com

(o) (925)388-0265

(c) (510)928-2683

"building energy simulations at your fingertips"

On 11/10/2015 7:52 PM, Nicholas Caton wrote:

This year at the 2015 ASHRAE Energy Modeling Conference, there was a
“Lowdown Showdown” design competition.  Voluntary teams representing most
commercial energy simulation software packages & platforms tried to tackle
a relatively open design challenge to bring a building (of our own design)
down to net-zero energy.  The relatively small team representing
eQUEST/DOE-2 won an award by popular vote for the “Most Creative” design
solution!



The eQUEST team had 5 members (all CC’ed on this email thread) - you may
recognize a few as frequent contributors over these mailing lists:

·       Aaron Powers

·       Cara Sloat

·       Pasha Korber-Gonzales

·       Chris Jones

·       Nick Caton



I served as ‘coach’ for the team, and in that context am very proud to
share some new information concerning our collaborative efforts, design
process, and the final ‘product’ with the greater eQUEST-users community.
Those who were able to attend the conference experienced a live
presentation by representatives for the teams and a panel discussion with
all of the coaches to field questions/challenges from the audience, but
time was quite constrained.  This this is an opportunity to share with
those who could not attend and to convey/discuss things in more detail.



Attached is a ‘poster’ that covers much of the information we presented for
the project, and outlines the process we followed over the ~9 weeks we had
to collaborate.  We accomplished a great deal in the time we had, in spite
of a late start due to some difficulties in assembling the minimum # of
members required.  The team met weekly via VOIP calls (Skype/join.me) to
coordinate efforts, present individual findings, and to simply share
knowledge and relate/compare experiences.  As a group, each individual
identified and contributed challenges/problems/systems of interest early
on, and as a group we made it a goal to incorporate those elements into our
project along the way.  This ‘spirit’ to tackle new/interesting issues and
to avoid “easy/obvious” solutions lead to some interesting design decisions
along the way!



I initially thought I would make it a personal goal to ensure the project
would be engaging, informative, and rewarding for every participant, but I
learned that with the right group that is going to happen anyway!  My only
regret is that more of my friends and colleagues in the industry did not
get to participate.  I sincerely hope when the next opportunity comes
along, more individuals from this community will take the initiative to
participate – it was very much worth our time!



If anybody would like to learn more or ask questions, please freely reply
to this email thread!



Kind regards,



~Nick



*NICK CATON, P.E.*
*Owner*



*Caton Energy Consulting*
  306 N Ferrel

  Olathe, KS  66061

  office:  785.410.3317

www.catonenergy.com
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