[Bldg-sim] One model

m.lebourhis m.lebourhis at elioth.fr
Thu Mar 19 04:14:13 PDT 2009


Hi all,

 

I am also currently working with IES-VE for LEED energy modeling. I am
finding it very efficient to compute the loads on the project I am working
on, which is quite huge and relatively complex in terms of
geometry/envelope.

However, it gets harder to model the water chilling plant as required by
Appendix G, and I am actually doing this part of the modelling with my own
excel calculation sheets and with DOE-2 curves. 

I was wondering; how will this approach be received by the USGBC? Could they
possibly require that the whole modeling is carried out with a single
package? Has anyone had problems validating EA1 with part of the energy
modelling being external to the simulation tool?

 

I have also been thinking of somehow using EnergyPlus or eQuest (preferably
the latter) just for the water chilling plant modeling. Has anyone ever used
one of these two tools to compute the systems energy from a cooling demand
calculated in an other simulation package?

 

Regards

Mathieu Le Bourhis

 

  _____  

De : bldg-sim-bounces at lists.onebuilding.org
[mailto:bldg-sim-bounces at lists.onebuilding.org] De la part de Field, Kristin
Envoyé : jeudi 12 mars 2009 21:40
À : bldg-sim at lists.onebuilding.org
Objet : Re: [Bldg-sim] One model

 

I tried out IES-VE a few months or a year ago with some people because the
potential for this type of integration seemed very exciting.  However, we
found the HVAC side to be pretty basic.  For a lot of building types, there
are significant savings to be had by changing HVAC control schemes and/or
configurations and using HVAC types that were not well-represented in IES-VE
the last time I saw it.  It seemed like a great interface to use if you were
trying to design a building to use minimal energy due to envelope,
orientation, natural ventilation, etc.  In other words, it seems strong on
the loads calculation side.  On the system use side, though, it seemed a lot
more limited than DOE2 or EnergyPlus.  For that reason, I have also stuck
with the multiple-tools method.  I agree with all who wrote that it would be
wonderful to have one integrated tool in the future!  Rob does bring up an
interesting point about the resolution of spaces needed for daylighting vs.
thermal vs. architectural modeling.  Architects especially have to be so
detailed in their models that I’ve often just ended up using the floor plans
they provided, deleting a bunch of elements out of those, and scaling wall
heights and windows.  Other than that, their 3D models only serve to help me
visualize the building myself.  It would be nice if we didn’t end up
tripling the effort like we all do now, but so far I don’t see a great way
around it (unless you don’t need complex system modeling – then you could
use IES-VE as discussed below).

 

Kristin Field

 

  _____  

From: bldg-sim-bounces at lists.onebuilding.org
[mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of CARNEY Ronan
Sent: Wednesday, March 11, 2009 10:34 PM
To: Rob Guglielmetti; Ross Harding
Cc: bldg-sim at lists.onebuilding.org
Subject: Re: [Bldg-sim] One model

 

Actually, I'm utilising IES to do HVAC design, Energy Analysis, PMV calc,
lighting lux design, lighting power intensity design and natural daylight
analysis all in line with the Australian Standards and Green Star (another
form of LEED) requirements. 

 

Although the software costs money, I've found it to be worthwhile battling
against it's flaws and it gives us the results which we require. 

 

Please note, this is a one model approach. It's easy to start a project at
CD (concept design) stage within Google Sketchup and to utilise the freeware
version of IES to do alternate design analysis. However, it's way better if
the full suite is purchases and the model is crossed over into IES. Within
IES multiple analysis and detailed designs can be modelled quickly and with
fantastic final project results. I know, I've done it.

 

Also with the daylight analysis, if you've got a detailed building with over
100000 surfaces, it's going to take forever to do the analysis, that's my
only issue with the software. However, the software is developing
multithreading facility within it's software, therefore decreasing the time
for analysis dramatically.

 

Should anyone want to discuss my approaches further, and are in Brisbane, I
welcome the opportunity to meet and greet with you.

Regards,
Ronan Carney
Electrical Engineer
Project Services
*Level 5B 80 George St Brisbane
*Ph: (07) 3224 5983
*Fax: (07) 3224 6151
*Email:  <mailto:Ronan.Carney at projectservices.qld.gov.au>
Ronan.Carney at projectservices.qld.gov.au 

 

  _____  

From: bldg-sim-bounces at lists.onebuilding.org
[mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Rob
Guglielmetti
Sent: Thursday, 12 March 2009 1:12 PM
To: Ross Harding
Cc: bldg-sim at lists.onebuilding.org
Subject: Re: [Bldg-sim] One model

 

On Mar 11, 2009, at 6:09 PM, Ross Harding wrote:

 

The ultimate goal for us would be to use one model for daylight and energy
models, but I haven’t found that quite that simple as most software requires
varying drawing techniques.

 

Amen brother!  Another issue is that while the energy model has to include
the total building -- all spaces and systems -- to be a complete picture of
the energy use, a Radiance-based daylight model does not necessarily require
all the spaces to be modeled simultaneously.  Indeed, the accuracy of the
ambient calculation is directly affected by the maximum size of the scene,
and so conducting a simultaneous daylight simulation of an entire building
at an acceptably rigorous ambient resolution can be -- is generally --
time-prohibitive.

 

As mentioned in a recent thread on this list, Thomas Bleicher's "su2rad"
plugin for SketchUp can export a SU model to Radiance format and there is
also an E+ plugin to allow one to use the same SU model for E+ analysis; in
theory, these three components (SketchUp, su2rad and the E+ plugin) allow
for a "single model" approach to energy and daylight modeling. However,
because the su2rad exporter wants to take the entire model and create a
single Radiance scene description, that creates the aforementioned problem
of the ambient calculation getting out of hand fairly quickly.  I suppose
through intelligent layering and model structuring, one could create a model
that could be exported to Radiance in "space components", but I'm not sure
if this is compatible with the E+ plugin's layering/model organization
requirements.

 

- Rob Guglielmetti

 

********************************************************

Kristin M. Field

Engineer II - Mechanical

Electricity, Resources & Building Systems Integration

National Renewable Energy Laboratory

1617 Cole Blvd.

Mail Stop #1725

Golden, CO  80401

Phone: 303.384.7376

Fax: 303.384.7540

 

 

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