[TRNSYS-users] building simulation

David BRADLEY d.bradley at tess-inc.com
Wed Dec 19 09:34:53 PST 2012


Matthias,
   I think the answer would depend a lot on the complexity of the HVAC 
systems and on the level of detail to which you would need to model 
them. The most comprehensive building models that I have done are for 
LEED projects (proposed building, proposed mechanical system, baseline 
(comparison) building, baseline (comparison) HVAC system, and lots of 
report writing). These projects can range from 70 to 200 hours of time 
with most coming in around 100 to 150. Again, though, that is modeling 
two buildings. To model just the one proposed building, I think you 
would probably be in the range of 50 to 150 hours.

   Some other thoughts for you, though (which I realize you didn't 
request... ;-)   ). Every model, every building simulation tool that is 
out there is some simplification of a real process. The more assumptions 
the model developer builds into the model, the simpler the model is to 
implement but the less flexible it becomes. The fewer assumptions that 
the developer builds in, the more flexible the tool but the more 
complexity there is involved with implementing a system model. I have 
found it helpful to think of building energy modeling tools on a sliding 
scale where on one end are tools that are relatively quick to use, which 
have a LOT of built-in assumptions and which are therefore not very 
flexible. One the other end are tools that are very flexible in terms of 
what you can model but which are more time consuming to use. TRNSYS is 
definitely on the "flexible but complex" end of that scale - 
intentionally so. If you are trying to model a building that has some 
unusual features (radiant floors, natural ventilation, double skin 
facades, complex HVAC systems, etc.) in it then TRNSYS is a good tool to 
use, even though it will require more hours to implement the model. If 
the building has nothing but conventional envelope and systems then 
there is no advantage to TRNSYS (or other tools like it); you will spend 
an unnecessarily long time implementing the model. On the other hand, it 
may be quick to implement a model in another software but if the 
building has features that cannot be modeled by the other software, you 
need to change to another, more comprehensive or flexible tool.

Best,
  David




On 12/12/2012 09:30, Matthias Maier wrote:
> Hi TRNSYS-users,
>
> I am studying electrical engineering at the Technical University of 
> Munich and currently I am writing my bachelor´s thesis at the 
> Institute for Energy Economy and Application Technology. My subject is 
> the comparison and assessment of various building simulation programs. 
> Background of this thesis is the development of an automatized demand 
> side management for commercial buildings, in case of the emergence of 
> a dynamic electricity tariff in Germany. Therefor a whole thermal 
> simulation of the building and it´s HVAC systems would be necessary.
>
> One of my tasks is to estimate the costs for the implementation of a 
> building including its HVAC systems. For this reason I selected an 
> example building to estimate the costs for (added in the attachment). 
> Support referred me to this user service. I would be very grateful if 
> anyone could tell me how long it takes to implement this example 
> building including its HVAC to TRNSYS and perform a high-resolution 
> simulation (minute-basis) for a eperienced user.
>
> Thank you for your attention.
>
> Regards,
> Matthias Maier
>
>
> _______________________________________________
> TRNSYS-users mailing list
> TRNSYS-users at cae.wisc.edu
> https://mailman.cae.wisc.edu/listinfo/trnsys-users

-- 
***************************
David BRADLEY
Principal
Thermal Energy Systems Specialists, LLC
22 North Carroll Street - suite 370
Madison, WI  53703 USA

P:+1.608.274.2577
F:+1.608.278.1475
d.bradley at tess-inc.com

http://www.tess-inc.com
http://www.trnsys.com

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