[Equest-users] *****SPAM***** RE: Team eQUEST: Lowdown Showdown Report

[Joe Huang]

Nick, Aaron,

Thanks for your thoughtful and detailed responses. I thought I'd use this reply to comment on both responses ( so, Aaron, don't go away ! :-) )

1) I think using a more detailed program for daylighting makes all the sense in the world, since the interactions between lighting and thermal are all one-way. Just one question, though, is how do you import the lighting schedule into DOE-2.2? If it were DOE-2.1E I would write a little User Function.

2) In respect to the appropriateness of using the Sherman-Grimsrud Infiltration Model to calculate air flows through large openings, I always recall my asking Max Sherman (the Sherman of the S-G model, one of the advantages of working at LBNL) that very question decades ago and was relieved to hear that not only was it okay, but it might actually work better since the equation is physics-based and better suited for bulk air flow than through cracks and tiny openings. As far as modeling dampers, there are several ways to handle it, with a "vent schedule" or by tweaking the discharge-coefficient, although that would mean setting up another User-Function. 

Joe

Sent from my iPad

> On Nov 16, 2015, at 5:14 AM, Nicholas Caton <ncaton at catonenergy.com> wrote:
> 
> 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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20151116/a708ccb4/attachment-0002.htm>