[Virtual-sim] [Bldg-sim] IES-VE Energy
wang95 at purdue.edu
wang95 at purdue.edu
Mon Mar 2 18:21:39 PST 2009
Dear Dr. Huang:
George didn't have much time on CONTAM97R since then. Simultaneous solution is
possible but needs a little bit more new derivations, which should work better
for highly-coupled thermal-airflow problems without the need of relaxations.
The CFD in CONTAM 3.0 is relatively faster than normal CFD, which is compiled
together and shares memory with CONTAM, instead of externally coupled. It
currently doesn't do annual simulations and thermal equation coupling but the
turbulence model and the solver algorithm can be improved for annual studies, if
there is really a need to predict annual data using CFD instead of EnergyPlus
etc. By the way, CONTAM 3.0 also provides an option of wind pressure and
contaminant profile predictions on building envelopes using CFD, which is very
useful for multizone indoor simulations.
Best regards,
Leon Wang
____________________________________
Liangzhu (Leon) Wang, PhD
lwang at nist.gov; wang95 at purdue.edu
Building Environment Division
National Institute of Standards and Technology
(301) 975-6447
100 Bureau Drive, Stop 8633
Gaithersburg, MD 20899-8633
____________________________________
Quoting Joe Huang <joe at drawbdl.com>:
> Leon,
>
> Nice to get this update on CONTAM97R. However, I'm surprised that the
> solutions
> are still "onion" (iterating between thermal and air flow program within
> each time step,
> for the benefit of those unfamiliar with the terminology) and
> "ping-pong" (passing boundary
> conditions without iteration), and not simultaneous, especially since
> Jim was quite
> critical of the ping-pong approach I was proposing for the
> EnergyPlus/COMIS link back
> in 2002. I'd also like to hear more about CONTAM 3.0 with CFD
> capability. Is this intended
> for annual simulations, or single snapshots? Does it also have thermal
> capabilities ?
>
> Joe Huang
> White Box Technologies
>
> wang95 at purdue.edu wrote:
> > Dear Dr. Huang and Dr. Glicksman:
> >
> > Yes, the work ended with up a program called CONTAM97R, which can do both
> onion
> > and ping-pong type of thermal-air couplings. The program has been used
> > internally for several projects related to natural/hybrid ventilation. We
> are
> > looking for the potential of extending its capability. Besides
> > Energyplus+Airnet, TRANSYS has a new type to couple with CONTAM too, which
> is
> > also under further development. By the way, we have a new version of CONTAM
> 3.0
> > with CFD capability, which is under beta testing. Hopefully, the new
> version
> > will be released publicly soon.
> >
> > Thanks,
> > Leon
> > ____________________________________
> >
> > Liangzhu (Leon) Wang, PhD
> > lwang at nist.gov
> > Building Environment Division
> > National Institute of Standards and Technology
> > (301) 975-6447
> > 100 Bureau Drive, Stop 8633
> > Gaithersburg, MD 20899-8633
> > ____________________________________
> >
> >
> > Quoting Joe Huang <joe at drawbdl.com>:
> >
> >
> >> Leon,
> >>
> >> That's very interesting. I know Jim Axley also worked with George
> >> Walton a decade or so ago to add heat conduction routines to CONTAM in
> >> order to simultaneously solve for heat and mass transport. I don't know
> >> whatever became of that work, though.
> >> Univ. of Colorado is now working on an ASHRAE project 1456-RP to
> >> evaluate methods to model natural ventilation, although so far they've
> >> only looked into coupled techniques, not simultaneous solutions. Have
> >> you considered using an existing thermal program for the thermal side of
> >> the equations ? I know that would be major surgery, but then you will
> >> have access to all the
> >> effort that's already done in modeling heat transfer and radiation.
> >>
> >> Joe Huang
> >> White Box Technologies
> >> 346 Rheem Blvd. Suite 108D
> >> Moraga CA 94556
> >> phone 1 925 388 0265
> >>
> >> Leon Glicksman wrote:
> >>
> >>> We are working on a natural ventilation program, CoolVent, that does
> >>> zonal analysis for multiple zones such as multistory open plan zones
> >>> connected to a central atrium. It simultaneously solves the energy and
> >>> momentum equations for each zone and includes thermal mass effects for
> >>> transient simulations. It is still under development.
> >>> Leon Glicksman
> >>>
> >>> Leon R. Glicksman
> >>> Professor of Building Technology and Mechanical Engineering
> >>> Massachusetts Institute of Technology
> >>> Room 5-418
> >>> 77 Massachusetts Avenue Cambridge, MA 02139
> >>> phone: 1 617 253 2233
> >>> e-mail : glicks at mit.edu
> >>>
> >>>
> >>>
> >>> Joe Huang wrote:
> >>>
> >>>> On the modeling of natural ventilation, I've not heard of anyone
> >>>> who's coupled thermal with CFD for annual simulations, and if they
> >>>> did I'd guess they're still waiting for the results! There are,
> >>>> however, several programs (EnergyPlus, ESPr) that do link up with a
> >>>> multi-zone air-flow network program (EnergyPlus uses AirNET/CONTAM)
> >>>> to "ping pong" with the thermal
> >>>> program. My experience doing an earlier linking of COMIS into
> >>>> EnergyPlus showed increases in runtimes of 2-3 times (that's on top
> >>>> of the standard run times most people have seen). I also saw
> >>>> instabilities in the "ping pong" approach that made me think of more
> >>>> iterations (horrors!), but the funding got cut so I didn't pursue that.
> >>>>
> >>>> As for eQuest handling of natural ventilation, its capabilities are
> >>>> probably the same as DOE-2.1E, which does have a very simple
> >>>> one-zone natural ventilation model that would calculate outside air
> >>>> flow rates based on that zone's leakage are, outside temperature, and
> >>>> wind speed. This capability was available first only in the RESYS
> >>>> system, but later extended to the other systems. I wouldn't use it to
> >>>> design a commercial building with hybrid ventilation, but for rough
> >>>> estimates of natural ventilation potentials for operable windows in
> >>>> perimeter offices, how bad is it ? Another nice thing about this
> >>>> natural ventilation feature in DOE-2 is that DOE-2 Systems first
> >>>> checks to see if NV can hold the setpoint temperature, and if not, it
> >>>> shuts off NV and turns on the mechanical system. Voila! The ideal
> >>>> natural ventilation control. I've yet to see such a control
> >>>> available in other programs.
> >>>>
> >>>> So, I get a little impatient when people talk about the capabilities
> >>>> of different programs in a yes-no context.
> >>>>
> >>>> Joe Huang
> >>>> White Box Technologies
> >>>>
> >>>>
> >>>> Karen Walkerman wrote:
> >>>>
> >>>>> Carol said most of it, and I definitely second the prohibitive cost
> >>>>> for a program like IES-VE for a small shop, but I've used Trace700,
> >>>>> which I assume uses an iterative algorithm (it took about 1-2 hours
> >>>>> run-time). So maybe using an iterative algorithm gives a little
> >>>>> more accuracy, I'd guess on the order of 2-5%, BUT many of these
> >>>>> programs don't allow you the flexibility in your inputs to take
> >>>>> advantage of the iterative nature of the program. For many systems,
> >>>>> you don't need to use an iterative program, you just need to know
> >>>>> the hourly space loads, hourly ventilation loads, and equipment
> >>>>> operation efficiencies at the given conditions. You need just a few
> >>>>> layers: component load (walls, windows, internal loads, etc), zone
> >>>>> loads, hvac system loads, loop loads and plant loads, in order to
> >>>>> get pretty good results. You need a few additional levels when your
> >>>>> systems get more compliated, but it doesn't require a
> >>>>> super-complicated algorithm.
> >>>>>
> >>>>> Bottom line is, many programs have their drawbacks. eQuest is not
> >>>>> good at modeling natural ventilation, precisely because it is not a
> >>>>> CFD program. If it were good at modeling natural ventilation, it
> >>>>> wouldn't be able to run in 1-2 minutes.
> >>>>>
> >>>>> I'd love to see a program that could integrate into two simulation
> >>>>> engines, one quick engine for trouble-shooting, doing DD models and
> >>>>> running lots of alternatives, and then an interative simulation
> >>>>> engine for more complex stuff, natural ventilation, complicated HVAC
> >>>>> system configurations, etc. Add that one to the wish-list! Maybe
> >>>>> we'll see it in 20 years.
> >>>>>
> >>>>>
> >>>>> --
> >>>>> Karen
> >>>>>
> >>>>> On 2/26/09, *Carol Gardner* <gems at spiritone.com
> >>>>> <mailto:gems at spiritone.com>> wrote:
> >>>>>
> >>>>> It can be better because you only have to do the renaming process
> >>>>> once and then your done whereas you are going to have to do the
> >>>>> rerunning way more than once: at least 4 orientation runs, a run
> >>>>> for each energy efficiency measure, a run each time you realize
> >>>>> you forgot to do the ____(fill it in). You are way further ahead
> >>>>> using eQUEST. I'm not sure what you mean by an interactive 3D
> >>>>> viewer, I find eQUEST's 3D views really helpful but I get the
> >>>>> impression you are talking about something else. At any rate, I
> >>>>> have used IESVE and E+ and I think they both excel in ways that
> >>>>> eQUEST doesn't but IESVE is just too expensive for a single shop
> >>>>> person like me and E+ is just too slow so far. I don't rule them
> >>>>> out for use when I'm rich and they're faster, though.
> >>>>>
> >>>>> Carol
> >>>>>
> >>>>> Paul Carey wrote:
> >>>>>
> >>>>>
> >>>>> Karen and all,
> >>>>>
> >>>>> I’m confused here....how can a program that takes up to 3
> >>>>> hours to rename the zones but then takes minutes to get
> >>>>> results, be better than something that takes a few minutes to
> >>>>> rename, but then takes a couple of hours to run? They are
> >>>>> about the same surely? The only advantage I can see is that
> >>>>> further iteration might be quicker in the former assuming your
> >>>>> geometry doesn’t change.
> >>>>>
> >>>>> I have been using various modelling tools such as IES VE, TAS
> >>>>> and DesignBuilder as well as a few other tools when necessary
> >>>>> (Fluent & CHAM CFD etc) since the late 90s. IES is good, it’s
> >>>>> quick to produce models and excellent for dynamic natural
> >>>>> ventilation design. TAS is better at the HVAC and natural
> >>>>> ventilation design aspects than IES and I think it’s more
> >>>>> accurate, but it’s front end still lacks some of the
> >>>>> functionality of other tools. Hopefully that is being
> >>>>> addressed by their links with Bentley. My colleague, Chris
> >>>>> Yates (also on this list) has become a bit of a wiz with the
> >>>>> sketchup plug in for IES and this appears to be much better
> >>>>> than relying on the gbxml output of revit.
> >>>>>
> >>>>> DesignBuilder is the tool that I use most now in both SBEM (UK
> >>>>> regulations format) and EnergyPlus for dynamic modelling. It
> >>>>> takes a lot of the best features of both IES and TAS and then
> >>>>> adds some other nice touches in terms of data application to
> >>>>> speed up the process of setting up your models. The only
> >>>>> sticking point with it is that EnergyPlus is painfully slow.
> >>>>> The main thing I’d like is for that to be changed and
> >>>>> improved. Carrying out simulations with all the lighting
> >>>>> controls and calculated natural ventilation turned on for
> >>>>> buildings with over 100 zones is nigh on impossible as I don’t
> >>>>> fancy leaving it running for a week or two. I have to carry
> >>>>> out major sub-division of models or calculate individual zones
> >>>>> then schedule up the vent based on those results or just go
> >>>>> with scheduled vent. Thankfully the reporting methodology from
> >>>>> DesignBuilder is pretty good, though I have to admit I quite
> >>>>> like some of the report wizard output by equest.
> >>>>>
> >>>>> The main advantage of the commercial tools as opposed to the
> >>>>> free tools such as DOE and equest, is that they use an
> >>>>> interactive 3d model to input the building and that you can
> >>>>> interrogate much more easily for post-processing. This means
> >>>>> you gain an understanding of the building form much more
> >>>>> easily and many link with other tools for further analysis. I
> >>>>> like some of what equest has to offer, but I much prefer the
> >>>>> interactive model building tools that IES, TAS and
> >>>>> DeisgnBuilder offer. They just make it...easier...and
> >>>>> generally quicker and more efficient when you consider the
> >>>>> other studies that you can do (e.g daylighting, CFD, etc).
> >>>>>
> >>>>> In terms of asking for changes having worked for IES (and
> >>>>> with many other developers), the stock answer even to their
> >>>>> own team was...yes it’s on the list. My guess is that will
> >>>>> still be the same.
> >>>>>
> >>>>> Regards
> >>>>>
> >>>>> Paul
> >>>>>
> >>>>> Dr Paul Carey
> >>>>>
> >>>>> Director
> >>>>>
> >>>>> Low Carbon Energy Assessor
> >>>>>
> >>>>> Zero Energy Design Ltd
> >>>>>
> >>>>> 10A Portland Place
> >>>>>
> >>>>> 2-22 Mottram Road
> >>>>>
> >>>>> Stalybridge
> >>>>>
> >>>>> SK15 3AD
> >>>>>
> >>>>> T: 0161 3386200
> >>>>>
> >>>>> F: 0161 3031281
> >>>>>
> >>>>> M: 0789 4098012
> >>>>>
> >>>>> E: paul at zed-uk.com <mailto:paul at zed-uk.com>
> >>>>>
> >>>>> W: www.zed-uk.com <http://www.zed-uk.com/>
> >>>>>
> >>>>> Certificate No: GB16647
> >>>>>
> >>>>> Certificate No: GB16646
> >>>>>
> >>>>> Please carefully consider the environment
> >>>>> before you print
> >>>>> this email.
> >>>>>
> >>>>> Company Registered in England & Wales. Registration No.
> 5815068
> >>>>>
> >>>>> Registered Address: 10A Portland Place, 2-22 Mottram Road,
> >>>>> Stalybridge, SK15 3AD, UK.
> >>>>>
> >>>>> _Privilege and Confidentiality Notice:___
> >>>>>
> >>>>> This email and any attachments to it are intended only for the
> >>>>> party to whom they are addressed. They may contain privileged
> >>>>> and/or confidential information. If you have received this
> >>>>> transmission in error, please notify the sender immediately
> >>>>> and delete any digital copies and destroy any paper copies.
> >>>>> Thank you.
> >>>>>
> >>>>> *From:* bldg-sim-bounces at lists.onebuilding.org
> >>>>> <mailto:bldg-sim-bounces at lists.onebuilding.org>
> >>>>> [mailto:bldg-sim-bounces at lists.onebuilding.org
> >>>>> <mailto:bldg-sim-bounces at lists.onebuilding.org>] *On Behalf Of
> >>>>> *Karen Walkerman
> >>>>> *Sent:* 25 February 2009 23:06
> >>>>> *To:* Varkie C Thomas
> >>>>> *Cc:* Varkie Thomas; bldg-sim at lists.onebuilding.org
> >>>>> <mailto:bldg-sim at lists.onebuilding.org>
> >>>>> *Subject:* Re: [Bldg-sim] IES-VE Energy
> >>>>>
> >>>>> Varkie,
> >>>>>
> >>>>> I disagree with your statement that eQuest is not appropriate
> >>>>> for large buildings because you can't change space names to
> >>>>> match architectural names in wizard mode, and the inputs
> >>>>> created from the wizard aren't appropriate for all spaces. The
> >>>>> wizards are called "Schematic Design Wizard" and "Design
> >>>>> Development Wizard" for a reason. They aren't desinged for
> >>>>> detail, they're designed to help you make big design decisions
> >>>>> quickly. If you want the building to be modeled as closely as
> >>>>> possible to the final design, this takes some extra work.
> >>>>> Yeah, re-naming spaces is a pain, but at 5 seconds per space,
> >>>>> re-naming 1,000 spaces takes about 1.5 hours, well worth the
> >>>>> effort. If you re-name zones too, maybe it's 3 hours total.
> >>>>>
> >>>>> Yeah, some things about eQuest are clumsy, like why does it
> >>>>> create one underground wall (and floor) consturction for each
> >>>>> surface, when only 4-5 are needed for the whole model? Why
> >>>>> does it re-create occupancy, lighting and micellaneous
> >>>>> equipment schedules for each shell, even if the use is the
> >>>>> same? And why does it create tons of duplicate infiltration
> >>>>> schedules? BUT... this takes an hour or two to clean up, and
> >>>>> then you have a decently flexible model that gives you
> >>>>> reasonable results in a matter of minutes. Versus a program
> >>>>> that takes 1-2 hours to run. I've done a few LEED projects in
> >>>>> Trace700 and it's painful modeling a design case and four
> >>>>> (rotated) base cases at 1-2 hours each, especially if you then
> >>>>> find you've left anything out.
> >>>>>
> >>>>> I definitely agree that there are some major things missing in
> >>>>> all modeling programs, which is why I'm putting together a
> >>>>> "Master Wish List" of modeler's desires. If you have things
> >>>>> that you would like to be able to model, things you'd like to
> >>>>> be able to model more easily, or things that you can do that
> >>>>> you feel are very important, please send me your list. I
> >>>>> currently have contact info for about 10 people representing
> >>>>> various simulation programs who want to know what we want!
> >>>>> Now's our chance to have some input!
> >>>>>
> >>>>> --
> >>>>> Karen
> >>>>>
> >>>>>
> >>>>> On Wed, Feb 25, 2009 at 2:15 PM, Varkie C Thomas
> >>>>> <thomasv at iit.edu <mailto:thomasv at iit.edu>
> >>>>> <mailto:thomasv at iit.edu <mailto:thomasv at iit.edu>>> wrote:
> >>>>>
> >>>>> Graham,
> >>>>>
> >>>>> The comment below stands out which might also be the reason
> >>>>> for not using EnergyPlus on large projects.
> >>>>>
> >>>>> - DOE-2.2 runs much quicker. For comparable 30,000 m2
> >>>>> buildings I would say DOE-2 runs in 1 minute and IES VE with
> >>>>> an APhvac network probably 1-2 hours. If you through in
> >>>>> Macroflo it probably adds another hour of simulation time. As
> >>>>> a result *iterative trial and error debugging* has to be done
> >>>>> on a 1-2 week period.
> >>>>>
> >>>>> Large building projects (1 to 10 million sqft) with up to
> >>>>> 1,000 zones and 70 systems ranging in size from 10,000 to
> >>>>> 200,000 cfm (pardon the English units - the USA & the Bahamas
> >>>>> are not going to switch to metric) require several iterative
> >>>>> runs to get the input errors fixed. Breaking up the project
> >>>>> into small pieces is not a solution since it affects demand
> >>>>> costs, central plants and other components. I have worked on
> >>>>> such projects using DOE2.1E and TRACE600/700.
> >>>>>
> >>>>> eQUEST is not suitable for such projects either. One of its
> >>>>> limitations is that you cannot enter the space names shown on
> >>>>> architectural drawings. Others include assuming all the input
> >>>>> data and making all the decisions for you when you enter the
> >>>>> type of building. 1000 zones means 1000 infiltration schedules
> >>>>> and multiples of other building components. It is unrealistic
> >>>>> to check all the input created by eQUEST for errors. Fixing
> >>>>> everything to match the exact project data has to be done in
> >>>>> detailed edit. Detailed edit means you lose access to the
> >>>>> graphical method of creating the building model from AutoCAD
> >>>>> drawings which is the main benefit of this program.
> >>>>>
> >>>>> Varkie
> >>>>>
> >>>>>
> >>>>>
> ------------------------------------------------------------------------
> >>>>>
> >>>>> _______________________________________________
> >>>>> Bldg-sim mailing list
> >>>>>
> >>>>> http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org
> >>>>> To unsubscribe from this mailing list send a blank message to
> >>>>> BLDG-SIM-UNSUBSCRIBE at ONEBUILDING.ORG
> >>>>> <mailto:BLDG-SIM-UNSUBSCRIBE at ONEBUILDING.ORG>
> >>>>>
> >>>>>
> ------------------------------------------------------------------------
> >>>>>
> >>>>> No virus found in this incoming message.
> >>>>> Checked by AVG - www.avg.com <http://www.avg.com/> Version:
> >>>>> 8.0.237 / Virus Database: 270.11.3/1971 - Release Date:
> >>>>> 02/25/09 06:40:00
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> ------------------------------------------------------------------------
> >>>>>
> >>>>> _______________________________________________
> >>>>> Bldg-sim mailing list
> >>>>> http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org
> >>>>> To unsubscribe from this mailing list send a blank message to
> >>>>> BLDG-SIM-UNSUBSCRIBE at ONEBUILDING.ORG
> >>>>>
> >>>>>
> >>>> _______________________________________________
> >>>> Bldg-sim mailing list
> >>>> http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org
> >>>> To unsubscribe from this mailing list send a blank message to
> >>>> BLDG-SIM-UNSUBSCRIBE at ONEBUILDING.ORG
> >>>>
> >> _______________________________________________
> >> Bldg-sim mailing list
> >> http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org
> >> To unsubscribe from this mailing list send a blank message to
> >> BLDG-SIM-UNSUBSCRIBE at ONEBUILDING.ORG
> >>
> >>
> >
> >
> >
> >
>
>
More information about the Virtual-sim
mailing list