[Bldg-sim] simulation software

[Nick Doylend]

Apologies for resurrecting this thread!  I've been trying to decide on
simulation software for LEED/ASHRAE 90.1 analyses.  I can't find any
evidence that DOE-2 based tools are requirement for LEED/ASHRAE 90.1
analysis but they seem to be the standard.  I'm concerned about the
likelihood of extra work justifying the use of alternative calculation
tools to third parties who may be unfamiliar with them.

Is there a list of accredited tools for LEED/ASHRAE 90.1, or a list of
software that has been assessed against ASHRAE 140? I've found this
page: (http://www.eere.energy.gov/buildings/info/qualified_software/),
which lists "Qualified Software for Calculating Commercial Building Tax
Deductions".  Is this relevant - eQuest is conspicuous by its absence.

Am I correct in thinking that both eQuest and Visual DOE are front ends
for DOE-2, and Design Builder is a front end for EnergyPlus.  I thought
EnergyPlus was an evolution of DOE-2, so why are tools continuing to use
the DOE-2 engine?

I appreciate the danger of relying on a graphical front end without a
good understanding of the underlying model description.  What's the
difference between DOE-2 and EnergyPlus in this respect?  How easy is it
to pick through a simulation model from the inside?  This may be quite
important if the front end doesn't provide the flexibility needed - it
may be necessary to go into the guts of the model...

Other things I'm interested include model exchange with other tools such
as Ecotect/Sketchup and CAD, possibly via gbXML import/export.

Training and support is an important consideration - how much of an edge
do commercial interfaces like VisualDOE and Design Builder have, over
software supported on a voluntary basis?  My company is based in the UK,
so local training and support are important - that counts heavily
against VisualDOE and in favour of Design Builder.  Internet mailing
lists are very useful, but there are occasions when a definitive answer
is needed right there and then.  Are there there third parties providing
paid-for support for the free packages?

A lot of questions - any answers, comments and recommendations much
appreciated.

Regards,

Nick Doylend

On Thu, 03 Jan 2008 13:05:53 -0600, "Varkie Thomas"
<thomasv at iit.edu> said:
> I agree with Jeff. Different programs may produce different energy
> savings results for USGBC LEED certification, depending on (a) the
> competence level of the program user, (b) the technical in-depth
> knowledge they have of this subject, (c) their experience in
> developing real buildings, (d) the design criteria that they use and
> (e) how well they understand the program they are  using.
>     Theoretically all programs should produce the same results for a
>     given project if the inputs are identical and the programs use the
>     same methods- equations for analyzing envelopes, systems and
>     plants. EnergyPlus uses the Heat-Balance method for Loads whereas
>     all the other programs use the Transfer-Function method.  Systems
>     & Plants depend on  the performance curves of the equipment.
>     Decisions have to take into account first & maintenance costs,
>     availability of equipment parts and maintenance staff, reliability
>     and durability of systems, positive environmental and acoustic
>     impacts, and client preferences.  This requires experience working
>     on real buildings. A mechanical engineering degree and P.E. are
>     more suitable qualifications for energy analysts than LEED A.P.
>     The “percent energy savings” requirement of LEED can be misleading
>     since it is affected by different design criteria, process loads,
>     internal loads schedules (these items have to be the same in the
>     baseline and proposed models) and the program used.  The higher
>     the common items in the baseline and proposed, the lower the
>     “percent” energy saved.  Sixty percent energy savings does not
>     necessarily mean an optimally designed, long lasting, stable and
>     cost-effective building at the given (particularly urban)
>     location. Varkie
>
>
> ----- Original Message ----- From: Jeff Haberl
> <jeffhaberl at tees.tamus.edu> Date: Saturday, December 29, 2007 12:29 pm
> Subject: Re: [Bldg-sim] simulation software To: Ardas at dfwcgi.com, bldg-
> sim at lists.onebuilding.org
>
> > FYI.
> >
> > Whatever package you use, gaining the type of experience needed to
> > do a reliable job usually takes 2 to 5 years. Especially with
> > "custom" systems that are not easily modeled with fixed schematic
> > programs.
> >
> > In addition, one should know what the programs is doing. All too
> > often there are posts to the different sites where it is clear the
> > user does no want to take the time to read the manual.
> >
> > At our university we teach DOE-2 from the BDL. This takes a whole
> > semester to cover all commands. After the student takes the class,
> > I'm told it takes them another year or two to build a library of
> > their own files that they ca use to assemble an input. EQUEST is
> > then the program of choice by the students as it is based on DOE-
> > 2. In the future we will be teaching EP.
> >
> > Using any GUI or REVIT is one or two levels above the basic code.
> > This can be very tempting -- but it requires the user to do their
> > own checking to see if the outputs make sense. Obviously, having on-
> > line help is useful but it cannot replace experience.
> >
> > All too often I see posts where someone says that this is their
> > first time to simulate something...this is good...and I applaud
> > anyone who tries to learn this on their own.
> >
> > But a reasonable person must ask would you want your heart surgeon
> > to be operating for the first time on you?
> >
> > Certainly, any paid simulation job should also be approached with
> > similar respect...these are just calculations, based on algorithms
> > and assumed configurations. If you can't tell what is being
> > simulated, then you're better off using a spreadsheet or rule of
> > thumb.
> >
> > Finally, any simulation should be reviewed by another knowledgable
> > person who makes the original coder explain what they are doing,
> > check answers, etc., and the performance of the building monitored
> > (as budget allows) to see how the simulation performed.
> >
> > Jeff BB 8=! 8=) :=) 8=) ;=) 8=) 8=( 8=) :=') 8=) 8=) 8=? BB
> >
> > Jeff S. Haberl, Ph.D.,
> > P.E.............................jhaberl at esl.tamu.edu Professor..-
> > ....................................................Office Ph:
> > 979-845-6507
> >
> > Department of Architecture.......................Lab Ph: 979-845-
> > 6065
> >
> > Energy Systems Laboratory.......................FAX: 979-862-2457
> >
> > Texas A&M University..............................77843-3581
> >
> > College Station, Texas, USA.......................URL: www-
> > esl.tamu.edu BB 8=/ 8=) :=) 8=) ;=) 8=) 8=() 8=) 8=? 8=) 8=) 8= BB
> >
> >
> > ----- Original Message ----- From: bldg-sim-
> > bounces at lists.onebuilding.org <bldg-sim-
> > bounces at lists.onebuilding.org>To: bldg-sim at lists.onebuilding.org <bldg-
> > sim at lists.onebuilding.org> Sent: Tue Dec 18 09:41:15 2007 Subject:
> > [Bldg-sim] simulation software
> >
> > hi,
> >
> > we are planning to use EQUEST or TRACE 700 for energy simulation.
> >
> > Is eQUEST an approved software by USGBC (in Texas)?
> >
> > Where can we get training in DFW (Dallas Fort Worth) area?
> >
> > Which one is easier, faster? Trace 700 or eQUEST?
> >
> > or do you know other simulation software (preferable free) that we
> > can utilize in our LEED design projects and we can get training in
> > DFW area? thanks
> >
> > Ardas
> >
> >
> >
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