[Bldg-sim] ASHRAE 2012 Energy Modeling Conference Topic for Discussion

[Karen Walkerman]

Two things:

1.  Some modeling software has lots of controls built into default HVAC
system types.  These controls are often better than what is planned or
installed for the building.  For example: economizers, demand controlled
ventilation or outdoor air reset might be assumed.  Similarly, on many
projects the HVAC controls drawings or sequence of operation is either
missing or not useful at all.  Without good information, it's tempting as a
modeler to assume efficient control of equipment.  However, on the actual
building, the opposite is likely to happen.

2.  Once I account for usage patterns, if a building I modeled during
design performs poorly in comparison to my model, I generally view at as
the building's "fault", and not the fault of my model.  The model can be a
great diagnostic tool for discovering where/how the building is not
operating as was modeled.  With a cooperative engineer and facilities
manager, we can usually make adjustments in building controls to bring the
building more closely in line with the model.  If the building was not
insulated properly, that is another matter, and post-occupancy adjustments
are difficult/impossible to make.  However, I would argue that the solution
is not to model poor construction and execution, but try to find a way to
use the model's projected energy data to keep the energy target in sight
through construction.

--
Karen

On Wed, Sep 5, 2012 at 10:52 AM, Matthew W. Higgins <MWHiggins at bpce.com>wrote:

>  Hi all. I’d like to echo Jim’s comment, and express excitement about
> what RMI is doing. Related to the “reality factor,” I’ve seen a tremendous
> gap between what LEED/GBCI wants and what will actually take place in the
> building, and the lack of sanity checks in modeling software. Though it is
> the responsibility of the modeler to perform sanity checks, and quality
> control, just spending the extra couple of hours each project can make the
> world of difference. On that end I’ve created a slew of my own sanity-check
> post-processing tools for eQuest and feel like our deliverables have
> improved significantly as a result.****
>
> ** **
>
> What some of the data our clients are sharing has begun to express the
> overwhelming need for these checks in all modeling, which includes analyses
> I’ve reviewed on behalf of our clients. In recent projects I’ve gone so far
> as to assume building-user error, reflected in schedules and temperatures,
> which has been spot on when comparing to metered data. This is somewhat
> taboo, because not many people are likely to voice these foreseeable
> shortcomings when delivering EUI’s during design that look inflated, for a
> new “high performance” building, but as sanity checks and associated tools
> develop it may become easier.****
>
> ** **
>
> What we can do, as an industry, is get better at setting expectations
> parallel to educating the building community about the usefulness/value of
> a good model.****
>
> ** **
>
> Great thread folks.****
>
> ** **
>
> Matthew Higgins, CEM, HBDP, LEED-AP (BD+C)* *
>
> *Energy Project Manager***
>
> * *
>
> *Bridgers & Paxton Consulting Engineers, Inc.*
>
> 4600-C Montgomery Blvd. NE****
>
> Albuquerque, NM  87109****
>
> 505.883.4111  *(t)*****
>
> 505.888.1436  *(f)***
>
> ** **
>
> ** **
>
> ** **
>
> *From:* bldg-sim-bounces at lists.onebuilding.org [mailto:
> bldg-sim-bounces at lists.onebuilding.org] *On Behalf Of *Ellen Franconi
> *Sent:* Tuesday, September 04, 2012 8:48 PM
> *To:* Ellis, David
> *Cc:* bldg-sim at lists.onebuilding.org
>
> *Subject:* Re: [Bldg-sim] ASHRAE 2012 Energy Modeling Conference Topic
> for Discussion****
>
> ** **
>
> This is a timely issue to be raised. I appreciate David Ellis' overview.
> As he states, the industry expects the need for adjustments/corrections to
> verified savings models so the same should nominally be expected for
> whole-building simulation models developed to inform design decision. ****
>
> ** **
>
> During the RMI Building Energy Modeling Summit (
> http://www.rmi.org/ReportsBEMInnovationSummit), the Methods & Processes
> break-out group came to agree that part of the modeling credibility
> challenge could be managed by addressing owner's expectations. We
> determined that modeling was performed for one of three objectives - 1) for
> making performance comparisons (e.g. comparing design options), 2)
> demonstrating compliance (e.g. LEED baseline or code) or 3) predicting
> performance. Depending on the objective, the level of effort and associated
> costs are different (as others have acknowledged on this email chain). The
> owner and statement of work need to recognize these differences. And as
> others have pointed out, a building simulation model assumes ideal
> conditions. It can be used to benchmark actual operation against and detect
> operational issues. But it can't be expected to reflect conditions other
> than those assumed in the model. ****
>
> ** **
>
> Inspired by the work plan developed by the Methods & Processes break out
> group (see link for final report and work plan), I submitted a proposal to
> DOE to complete work in line with what David proposed for the industry. We
> are just getting it underway. We refer to it as the Building Energy
> Modeling Library or Modeling for Investor Confidence. While this is a broad
> area, we are starting by structuring and documenting modeling best practice
> procedures to facilitate their use in modeling guidelines, standards,
> scopes of work etc. As much as possible, we aim to include risk
> assessment/management into the methods. Once developed, the methods will be
> posted on the internet. I'll share our progress as we go with the
> list-serve. ****
>
> ** **
>
> I also recently co-authored a paper on risked-based building energy
> modeling, which provides a pretty good overview and some new ideas to
> support the topic. If anyone is interested to read it. let me know and I'll
> email you a copy.****
>
> ** **
>
> Best regards,****
>
> Ellen. ****
>
> ** **
>
> On Tue, Sep 4, 2012 at 2:49 PM, Ellis, David <David.Ellis at hdrinc.com>
> wrote:****
>
> Bill, Jim, Dennis, et al ****
>
>  ****
>
> This is a tough nut. In the ESPC or ESCO world, where performance must be
> depended upon to achieve financial returns, there are understood and
> controlling processes in what equipment is bought, how it is installed, how
> it is maintained, how it is operated and expected duty schedule. Contracts
> are written to reduce uncertainty to the point that in some cases any
> deviance, in seemly minor matters, throws the performance expectations up
> for renegotiations.****
>
>  ****
>
> While weather changes can be adjusted for after the fact (and thus readily
> understood as a reason for some differences between real and modeled
> performance), outside of the ESPC/ESCO arena, a design engineer/modeler can
> make their best fine tuned efforts on construction intent equipment and
> operations, to be undone by changes in installation, commissioning,
> operational practices and occupancy that are not under their control, and
> are frequently difficult to document after the fact.****
>
>  ****
>
> In the design arena, modeling is a means to assess options on a level
> plane, and should not be offered as a predictor of actual cost unless that
> risk is fully evaluated and compensated for (both in labor/risk fees and in
> the processes to assure changes are documented). There is a real need to
> fully vet an industry standard approach to identifying the risks (for fair
> negotiation), and establishing standards in best practices.****
>
>  ****
>
> Yes, our modeling does inform sequences of operations, as strategies can
> be involved, and are a combined designer and modeler effort. They do indeed
> make their way into construction intent documents … but implementation and
> ongoing maintenance are another matter.****
>
>  ****
>
> A calibrated model is an excellent tool for more realistically evaluating
> operational and systems changes. But here too, the results should be
> considered as a way to evaluate options on a level playing field, as
> control over so many variables is out of the modelers scope.****
>
>  ****
>
> I would encourage the development of collective industry guidance towards
> understanding these risks and offering clarification on expectations for
> client informational purposes.****
>
>  ****
>
> *David Ellis
> *PE (VA, MD, DC)****
>
> LEED AP BD+C****
>
> CEM****
>
> PMP****
>
> *HDR Architecture Inc**
> *Energy Services Technical Director, NC****
>
> 1101 King Street, Suite 400  | Alexandria, VA 22314
> 703.647.7735 | c: 703.343.6758
> David.Ellis at hdrinc.com <first.last at hdrinc.com> | hdrarchitecture.com<http://www.hdrinc.com/markets/architecture>
> ****
>
> Follow Us – *Architizer<http://www.architizer.com/en_us/firms/view/hdr-architecture/8916/>|
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>
>  ****
>
>  ****
>
> *From:* Bishop, Bill [mailto:bbishop at pathfinder-ea.com]
> *Sent:* Tuesday, September 04, 2012 11:33 AM
> *To:* Jim Dirkes; Dennis Knight; bldg-sim at lists.onebuilding.org****
>
>
> *Subject:* Re: [Bldg-sim] ASHRAE 2012 Energy Modeling Conference Topic
> for Discussion****
>
>  ****
>
> Jim said most of what I was going to say. Additionally,****
>
> ·         An energy modeler’s task for a new construction project is
> rarely to accurately predict energy use, but to demonstrate compliance
> with, and improvement over, code performance.****
>
> ·         Modelers generally do not fine tune plug loads, occupant
> numbers and schedules etc. because these are kept identical for determining
> improved performance over code.****
>
> ·         Sequence of operations. The modeler is usually not the engineer
> of record, and should therefore not be dictating the sequence of operations
> of HVAC/plant equipment. I may provide the mechanical engineer with
> suggestions on controls strategies and setpoints, and sometimes they are
> receptive. However, my focus as energy modeler is energy, and not comfort,
> system complexity or reliability. Regardless, the exact sequence of
> operations, even if meticulously described in the design documents, may not
> be implemented, or may be changed many times during the first year or two
> of building operation.****
>
> ·         No/poor commissioning of buildings. Buildings designed to be
> very energy efficient often rely on complex controls for HVAC and lighting
> systems. Many buildings are not commissioned, and even in the ones that
> are, commissioning is often little more than verifying that the equipment
> and controls were installed as designed. The commissioning agent rarely has
> the time/budget/scope to determine that all control strategies are
> operating as designed. Also, the commissioning agent cannot change the
> weather conditions during which the building is commissioned, making it
> next to impossible to check CHW controls during winter for example.****
>
> ·         New buildings often go through many changes in operating
> conditions during their first year or two. New buildings are often in use
> after hours due to people moving into their new offices, or because they
> are nice facilities and the demand to utilize them is high.****
>
> ·         One of the best ways to predict energy performance is data
> mining of existing building performance. Hopefully, CBECS and other
> building performance databases will be a big area of focus for our field.*
> ***
>
>  ****
>
> **** <wbishop at pathfinder-ea.com>
>
>  **** <wbishop at pathfinder-ea.com>
>
> *From: bldg-sim-bounces at lists.onebuilding.org [
> mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Jim Dirkes
>  <wbishop at pathfinder-ea.com>*
> *Sent: Tuesday, September 04, 2012 10:56 AM
> To: Dennis Knight; bldg-sim at lists.onebuilding.org
> Subject: Re: [Bldg-sim] ASHRAE 2012 Energy Modeling Conference Topic for
> Discussion <wbishop at pathfinder-ea.com>*
>
>   **** <wbishop at pathfinder-ea.com>
>
> Dear Dennis and BldgSim Community,**** <wbishop at pathfinder-ea.com>
>
> 1.       I think the tools are absolutely up to the task.  My own
> practice uses EnergyPlus exclusively, but I know that most of the other
> tools are based in solid thermodynamic and physical principles – so they
> start on a solid foundation.**** <wbishop at pathfinder-ea.com>
>
> 2.       Current best practices is another story altogether!****<wbishop at pathfinder-ea.com>
>
> a.       Keeping in mind that I know only the “Best practices” for my own
> firm …**** <wbishop at pathfinder-ea.com>
>
> b.      Energy modelers of new construction are normally given scant
> information.  **** <wbishop at pathfinder-ea.com>
>
> ·   Partly this is due to the owner not knowing exactly how the new
> facility will be used.**** <wbishop at pathfinder-ea.com>
>
> ·   Partly this is due to the Owner and Designer not caring about, not
> appreciating the importance of, or just not needing to gather detailed
> information about the operation of a building that hasn’t been built.****<wbishop at pathfinder-ea.com>
>
> ·   Partly it’s because “as built” is never “as designed”. (Think of fan
> and pump pressure estimates differing from actual, weather variances,
> occupancy schedule changes, etc.)**** <wbishop at pathfinder-ea.com>
>
> ·   The energy modeling community has, it seems, a lot of bright young
> men and women who are “learning the ropes”.  The fact that they are
> becoming involved is very exciting!  Their education must be broadened,
> however, in order for them to become effective at modeling existingbuildings. It’s no longer just theory;  there is a lot of practical, “hands
> on” activity that is needed.**** <wbishop at pathfinder-ea.com>
>
> 3.       Inferred above is the host of variables that differ in an actual
> building’s operation from what may have been assumed.  The older the
> building, the more variations there are!**** <wbishop at pathfinder-ea.com>
>
> 4.       Most building operators, if they exist within the building as a
> full time position, are distracted with many other details and spent
> precious little time optimizing energy performance.  If there is no full
> time building operator …..**** <wbishop at pathfinder-ea.com>
>
> 5.       This is a field ripe with opportunity!  The first and hardest
> task, I think, is to get building owners convinced that the ROI for optimal
> building performance is better than any of their other opportunities for
> investing.  The next task is to streamline the process of calibration and
> identification of opportunities so that they is faster and more economical.
> **** <wbishop at pathfinder-ea.com>
>
> 6.       … and I’d love to expand this discussion during the Q&A period
> at my presentation on this topic during the ASHRAE Energy Modeling
> Conference!**** <wbishop at pathfinder-ea.com>
>
>  **** <wbishop at pathfinder-ea.com>
>
> *James V Dirkes II, PE, BEMP, LEED AP
> www.buildingperformanceteam.com
> Energy Analysis, Commissioning & Training Services
> 1631 Acacia Drive, Grand Rapids, MI 49504 USA
> 616 450 8653 <wbishop at pathfinder-ea.com>*
>
>  **** <wbishop at pathfinder-ea.com>
>
> *From: bldg-sim-bounces at lists.onebuilding.org [
> mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Dennis Knight
> Sent: Tuesday, September 04, 2012 10:24 AM
> To: bldg-sim at lists.onebuilding.org
> Subject: [Bldg-sim] ASHRAE 2012 Energy Modeling Conference Topic for
> Discussion <wbishop at pathfinder-ea.com>*
>
>  **** <wbishop at pathfinder-ea.com>
>
> I am the Chair of the conference committee for the ASHRAE 2012 Energy
> Modeling Conference that will be held in Atlanta on October 1, 2 & 3 this
> year (see link below).  The conference is focused on bringing
> practitioners, software developers, researchers and facility users together
> for 3 days of in depth discussion on current modeling software capabilities
> and current best practices in energy modeling.  I have two questions that I
> would like to pose to this group to get some feedback to help provider
> richer content for the discussions planned at the conference;****<wbishop at pathfinder-ea.com>
>
> 1. Are the current energy modeling tools available to an energy modeling
> practitioner reliable enough to allow the modeler to predict a building's
> actual energy consumption with a high degree of confidence such that an
> accurate energy target can be established and recommended to the building
> owner for the new building or a  renovation/retrofit? ****<wbishop at pathfinder-ea.com>
>
> 2. Are the current best practices of the energy modeling
> community reliable enough, and well understood by most practitioners, to
> allow the modeler to predict a building's actual energy consumption with a
> high degree of confidence such that an accurate energy target can be
> established and recommended to the building owner for the new building or a
> renovation/retrofit? **** <wbishop at pathfinder-ea.com>
>
>  **** <wbishop at pathfinder-ea.com>
>
> Background for the discussion:**** <wbishop at pathfinder-ea.com>
>
> These questions recently came up in a discussion among the conference
> committee.  It seems that one our colleagues from the UK indicated that in
> the UK new schools have performed very poorly in comparison with their
> predicted energy use.**** <wbishop at pathfinder-ea.com>
>
>  **** <wbishop at pathfinder-ea.com>
>
> Another comment that was made was as follows:****<wbishop at pathfinder-ea.com>
>
> "Often a building's actual energy consumption is 1.5 to 2 times as much as
> the results of an energy model that was used to make decisions during
> design about the building's energy using systems.  Is it the the energy
> modeling tools or is it the processes used by energy modelers to describe
> the systems and how they operate in the software? Should energy models be
> used to "predict" a building's future energy performance or just be used to
> inform better decisions during design?**** <wbishop at pathfinder-ea.com>
>
>  **** <wbishop at pathfinder-ea.com>
>
> I have reviewed a good many models and, almost without fail, I never see a
> modeler start by writing a sequence of operation and I also never see the
> sequence of operation used by the modeler make its way into a set of
> construction documents.  **** <wbishop at pathfinder-ea.com>
>
>  **** <wbishop at pathfinder-ea.com>
>
> Also, when I am the modeler and I am "calibrating" a model to an existing
> building's actual energy consumption it is a very iterative process.  I
> know what things to manipulate in the model to effect demand and what
> things to manipulate to effect consumption.  I just keep going back and
> forth until I have a model that you can almost lay its output on top of the
> building's utility bill history. I also have a good understanding of how
> the building is actually being operated and maintained - which I hope helps
> make the model more accurate, but, does that process really give me a
> better model to make decisions from?"**** <wbishop at pathfinder-ea.com>
>
>  **** <wbishop at pathfinder-ea.com>
>
>  **** <wbishop at pathfinder-ea.com>
>
> I invite everyone to please, tell us what you think.****<wbishop at pathfinder-ea.com>
>
> Sincerely,**** <wbishop at pathfinder-ea.com>
>
>  **** <wbishop at pathfinder-ea.com>
>
>  **** <wbishop at pathfinder-ea.com>
>
>  **** <wbishop at pathfinder-ea.com>
>
>  **** <wbishop at pathfinder-ea.com>
>
>  **** <wbishop at pathfinder-ea.com>
>
> Link to conference webpage: *
> http://www.ashrae.org/membership--conferences/conferences/ashrae-conferences/emc2012
> ***** <wbishop at pathfinder-ea.com>
>
>  **** <wbishop at pathfinder-ea.com>
>
>
> **** <wbishop at pathfinder-ea.com>
>
>  **** <wbishop at pathfinder-ea.com>
>
> --
> M. Dennis Knight, P.E.**** <wbishop at pathfinder-ea.com>
>
> Founder & CEO**** <wbishop at pathfinder-ea.com>
>
> *Whole Building Systems, LLC <wbishop at pathfinder-ea.com>*
>
> P.O. Box 1845**** <wbishop at pathfinder-ea.com>
>
> Mt. Pleasant, SC 29465**** <wbishop at pathfinder-ea.com>
>
> Phone: *843-437-3647***** <wbishop at pathfinder-ea.com>
>
> Email: *dknight at wholebuildingsystems.com***** <wbishop at pathfinder-ea.com>
>
> Website: *www.wholebuildingsystems.com***** <wbishop at pathfinder-ea.com>
>
>  **** <wbishop at pathfinder-ea.com>
>
>  **** <wbishop at pathfinder-ea.com>
>
>
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> **** <wbishop at pathfinder-ea.com>
>
> ** ** <wbishop at pathfinder-ea.com>
>
> --
> Ellen Franconi, PhD, LEED AP, BEMP
> Senior Consultant, Built Environment Team
>
> Rocky Mountain Institute
> 1820 Folsom Street
> Boulder, CO 80302
> 303.567.8609 (Desk)
> 303.245.7213 (Fax)
>
> Rocky Mountain Institute drives the efficient and restorative use of
> resources, creating a world thriving, verdant, and secure, for all, for
> ever.
>
> *http://www.rmi.org***** <wbishop at pathfinder-ea.com>
>
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