[TRNSYS-users] Fwd: Error creating the wall transfer function coeffients

Jean Marais jeannieboef at gmail.com
Sat Nov 17 12:18:33 PST 2012 

Maybe Trnsys should think of employing a different solver that can be
applied where you want it. For example the latest eneryplus v7.2, you can
use the conduction finite difference algorithm for select constructions
whilst the rest run on the default CTF algorithm. Some years ago, I also
had models with these issues.

On 17 November 2012 20:42, leen peeters <l.f.r.peeters at gmail.com> wrote:

> Karol,
>
> the transfer functions have some limitations, especially with heavyweight
> largely insulated constructions. You can check out the old TRNSYS manuals
> to find out more.
> The group of Michael Kummert in Montreal is doing more research to try to
> lower the timeconstant. They found a trick to lower the time constant. That
> was by adding an active layer (that is not used) in the heavyweight layer.
> That way, the transfer function coefficients are calculated differently,
> allowing a lower value of the time base. I have done some test runs with
> different time steps and, as expected, it does influence the results. In my
> case I tested a configuration with time base of 2 versus 5 hours. The
> deviation on the energy consumption was up to 10% for a specific room.
> 9 hours is way too high, so try the active layer approach.
>
> leen
>
>
>
> On Sat, Nov 17, 2012 at 6:28 PM, ÍõÑó <wanghongyang1767 at gmail.com> wrote:
>
>> Dear leen,
>>
>> Thanks for your email!
>> I tried till 9 hours as the TIMEBASE which can work. But could you please
>> tell me the detailed reasons for that? i.e. why we need so large TIMEBASE 9
>> hours to meet its Stability Criteria?
>>
>>
>> Thanks in advance!
>> Br.
>> wang
>>
>>
>> 2012/11/16 ÍõÑó <wanghongyang1767 at gmail.com>
>>
>>> Dear leen,
>>>
>>> Thanks for your email!
>>> I tried till 9 hours as the TIMEBASE which can work. But could you
>>> please tell me the detailed reasons for that? i.e. why we need so large
>>> TIMEBASE 9 hours to meet its Stability Criteria?
>>>
>>>
>>> Thanks in advance!
>>> Br.
>>> wang
>>>
>>>  2012/11/15 leen peeters <l.f.r.peeters at gmail.com>
>>>
>>>> Can you open in TRNBUILD the 'project' window, and consequently the
>>>> 'outputs', change the timebase for calculation of your transfer function to
>>>> something higher. I think it is standard on 2 hour, change it into 5,
>>>> check. If it works, then try 4, ..... until you reach the lowest possible
>>>> number
>>>>
>>>>
>>>> On Thu, Nov 15, 2012 at 10:28 PM, ÍõÑó <wanghongyang1767 at gmail.com>wrote:
>>>>
>>>>> Dear all,
>>>>>
>>>>> I have a question about *.BUI file. I create a project with about 30
>>>>> zones using TRNSYS 16.
>>>>> Before I created the seventeenth zone using the same exterior wall and
>>>>> floor as well as interior wall etc for the project, it worked well. But
>>>>> when the seventeenth zone created, it appeared an ERROR in TRNBuild: Error
>>>>> creating the wall transfer function coeffients. Please see the
>>>>> attached figure. The second file is its INF file.
>>>>>
>>>>> If you had some relative experience, PLEASE tell me how to solve with
>>>>> this problem.
>>>>>
>>>>> Thanks in advance!
>>>>> Br.
>>>>> wang
>>>>>
>>>>> ---------- Forwarded message ----------
>>>>> From: ÍõÑó <wanghongyang1767 at gmail.com>
>>>>> Date: 2012/11/15
>>>>> Subject: Error creating the wall transfer function coeffients
>>>>> To: trnsys-users at cae.wisc.edu
>>>>>
>>>>>
>>>>> Dear all,
>>>>>
>>>>> I have a question about *.BUI file. I create a project with about 30
>>>>> zones using TRNSYS 16.
>>>>> Before I created the seventeenth zone using the same exterior wall and
>>>>> floor as well as interior wall etc for the project, it worked well. But
>>>>> when the seventeenth zone created, it appeared an ERROR in TRNBuild: Error
>>>>> creating the wall transfer function coeffients. Please see the
>>>>> attached figure. The second file is its INF file.
>>>>>
>>>>> If you had some relative experience, PLEASE tell me how to solve with
>>>>> this problem.
>>>>>
>>>>> Thanks in advance!
>>>>> Br.
>>>>>
>>>>> wang
>>>>>
>>>>> 2012/11/12 <trnsys-users-request at cae.wisc.edu>
>>>>>
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>>>>>> than "Re: Contents of TRNSYS-users digest..."
>>>>>>
>>>>>> Today's Topics:
>>>>>>
>>>>>>    1. Re: Type 15-2: Relationship between data arrangements,
>>>>>>       simulation times and convergence (David BRADLEY)
>>>>>>    2. simulation trend opposite to reality (validation)
>>>>>>       (Karol Bandurski)
>>>>>>
>>>>>>
>>>>>> ---------- ÒÑת·¢Óʼþ ----------
>>>>>> From: David BRADLEY <d.bradley at tess-inc.com>
>>>>>> To: Flynn Ciaran <ciaran.flynn at aalto.fi>
>>>>>> Cc: "trnsys-users at cae.wisc.edu" <trnsys-users at cae.wisc.edu>
>>>>>> Date: Mon, 12 Nov 2012 11:09:38 -0600
>>>>>> Subject: Re: [TRNSYS-users] Type 15-2: Relationship between data
>>>>>> arrangements, simulation times and convergence
>>>>>> Ciar¨¢n,
>>>>>>   Option 1) is incorrect. Type15 is intended to be used with
>>>>>> year-long weather files that have a 1-hour data interval. The component
>>>>>> knows from the simulation start and stop time what day of the year it is,
>>>>>> so if you trick it by setting the simulation start time to hour zero and
>>>>>> rearrange the weather file to start in the middle of the year, what the
>>>>>> Type calculates about the sunup and sundown times and what the data file
>>>>>> says is happening are not going to match at all. Option 2 is the only
>>>>>> correct one.
>>>>>> Best,
>>>>>>  David
>>>>>>
>>>>>>
>>>>>> On 11/12/2012 06:32, Flynn Ciaran wrote:
>>>>>>
>>>>>>  Hello,****
>>>>>>
>>>>>> ** **
>>>>>>
>>>>>> I have a couple of questions concerning the relationship between the
>>>>>> arrangement of data in TMY2 weather files, TRNSYS simulation times and
>>>>>> convergence errors. I tried looking at the source code but I could not
>>>>>> figure out the answer..
>>>>>> I am running a simulation for one year, using Type 15-2 for weather,
>>>>>> starting at 1h on July 1st and ending at 24h on June 30th. This
>>>>>> leaves me with two options:
>>>>>> 1) Either I rearrange the tm2 file to start at 1h on the 1st of July
>>>>>> and end at 24h on June 30th, and set the simulation start and stop
>>>>>> times to 0 and 8760h respectively, or
>>>>>> 2) Either I leave the weather file as it is and set the simulation
>>>>>> start and stop times at 4344h and 13104h respectively.****
>>>>>>
>>>>>> ** **
>>>>>>
>>>>>> When I use a provided weather file (e.g. CA-BC-Vancouver-718920.tm2)
>>>>>> and set the simulation time step at 0.1h, I get the following:****
>>>>>>
>>>>>> ** **
>>>>>>
>>>>>> ** **
>>>>>>
>>>>>> Failed convergence time steps****
>>>>>>
>>>>>> Time steps where:
>>>>>> calculated total horizontal radiation > horizontal extraterrestrial
>>>>>> radiation****
>>>>>>
>>>>>> Time steps where:
>>>>>> direct normal radiation > solar constant****
>>>>>>
>>>>>> Time steps where:
>>>>>> calculated horizontal beam radiation > total horizontal radiation****
>>>>>>
>>>>>> 1)****
>>>>>>
>>>>>> 7719****
>>>>>>
>>>>>> 10664****
>>>>>>
>>>>>> 124****
>>>>>>
>>>>>> 3498****
>>>>>>
>>>>>> 2)****
>>>>>>
>>>>>> 6424****
>>>>>>
>>>>>> -****
>>>>>>
>>>>>> -****
>>>>>>
>>>>>> 13****
>>>>>>
>>>>>> ** **
>>>>>>
>>>>>> So my question are:****
>>>>>>
>>>>>> -          Why is TRNSYS giving different error messages if the same
>>>>>> weather data are used ? (I believe that there are no other types in my file
>>>>>> that could explain the reason for this)****
>>>>>>
>>>>>> -          What parameters do the radiation values calculated by
>>>>>> TRNSYS depend on and how are they calculated? ****
>>>>>>
>>>>>> -          What is the best approach in this situation (minimal
>>>>>> radiation errors)?****
>>>>>>
>>>>>> ** **
>>>>>>
>>>>>> Thanks a lot,****
>>>>>>
>>>>>> Ciar¨¢n****
>>>>>>
>>>>>> ** **
>>>>>>
>>>>>> ** **
>>>>>>
>>>>>> ** **
>>>>>>
>>>>>> ** **
>>>>>>
>>>>>>
>>>>>> _______________________________________________
>>>>>> TRNSYS-users mailing listTRNSYS-users at cae.wisc.eduhttps://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:+1.608.278.1475d.bradley at tess-inc.com
>>>>>> http://www.tess-inc.comhttp://www.trnsys.com
>>>>>>
>>>>>>
>>>>>>
>>>>>> ---------- ÒÑת·¢Óʼþ ----------
>>>>>> From: "Karol Bandurski" <karol.bandurski at put.poznan.pl>
>>>>>> To: <trnsys-users at cae.wisc.edu>, <bldg-sim at lists.onebuilding.org>
>>>>>> Cc:
>>>>>> Date: Mon, 12 Nov 2012 18:22:45 +0100
>>>>>> Subject: [TRNSYS-users] simulation trend opposite to reality
>>>>>> (validation)
>>>>>>
>>>>>> Dear All,****
>>>>>>
>>>>>> ** **
>>>>>>
>>>>>> I simulate the dwelling in TRNSYS. Last time a try to validate my
>>>>>> model and I compare simulation results with measurements.****
>>>>>>
>>>>>> *Heat consumption* has been measured in dwelling every week (the
>>>>>> same day of week and the same hour).****
>>>>>>
>>>>>> Trnsys simulation generate results for dwelling¡¯s model with ideal
>>>>>> heating assumptions (set temperature 20/21) ¨CNTYPE2 (sensible *energy
>>>>>> demand*).****
>>>>>>
>>>>>> ** **
>>>>>>
>>>>>> Total *heat consumption (measurements)* of dwelling and *energy
>>>>>> demand (simulation)* of simulated model are quite similar (36 weeks
>>>>>> from September to June), but if we look on weekly results there are bigger
>>>>>> difference with interesting regularity:****
>>>>>>
>>>>>> ** **
>>>>>>
>>>>>> if *heat consumption* decreases from one week to the next, then *energy
>>>>>> demand* increase, and vice versa (I enclose graph).****
>>>>>>
>>>>>> ** **
>>>>>>
>>>>>> Could you tell me what can cause this lack of coincidence?****
>>>>>>
>>>>>> I will be grateful for any hints!****
>>>>>>
>>>>>> ****
>>>>>>
>>>>>> Regards,****
>>>>>>
>>>>>> Karol****
>>>>>>
>>>>>> ** **
>>>>>>
>>>>>> ------------------------------------------------****
>>>>>>
>>>>>> Karol Bandurski MSc.****
>>>>>>
>>>>>> Institute of Environmental Engineering <http://www.ee.put.poznan.pl/>
>>>>>> ****
>>>>>>
>>>>>> Poznan University of Technology****
>>>>>>
>>>>>> www.ee.put.poznan.pl****
>>>>>>
>>>>>> www.put.poznan.pl****
>>>>>>
>>>>>> ** **
>>>>>>
>>>>>> _______________________________________________
>>>>>> TRNSYS-users mailing list
>>>>>> TRNSYS-users at cae.wisc.edu
>>>>>> https://mailman.cae.wisc.edu/listinfo/trnsys-users
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> TRNSYS-users mailing list
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>>>>>
>>>>>
>>>>
>>>
>>
>
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