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Re: [TRNSYS-users] How to calculate pressure difference(pa)



Wang,
  If you are defining the pressure difference value in the test data option then typically you would have the results of a "blower door" test in which a special door containing a computer controlled fan is installed in the building. The fan is run at different speeds to force a pressure difference between indoors and outdoors. Running the fan at various speeds can give you an estimate of the total leakage area of the building. If you are working with a building design (instead of with an actual building) then you can't really use the "test data" type of opening in TRNFlow. You need to use the more theoretical opening types.
Regards,
 David


On 7/4/2011 08:14, 王洋 wrote:
Dear Mr. Bradley,
 
    Thanks for your patient reply!
 
   To the pressure difference between indoors and outdoors:
Do you mean it's difficult to use some measuring devices and methods to test it? Whether there is no an Maths Equation  to calculate this value according to known data e.g. building height, wind spead etc.?
 
   Because I need one pressure difference(pa) value in Test Data Option of TRNFLOW.
 
  Many thanks!
 
 br.
 
wang 


2011/7/1 王洋 <wanghongyang1767@gmail.com>

 
2011/3/16 David BRADLEY <d.bradley@tess-inc.com>
Wang,
 Chapter 18 is the one you need; look specifically on page 18.19 at the mathematical description of the conduction process through the walls.

 As for your question about pressure differences, the pressure difference between indoors and outdoors varies with a great many factors (windspeed, direction, obstructions, building height, the nature of the openings in the building facades, etc.). In many tests, the flow through an opening with a 50Pa pressure difference is given. Whether a 50Pa pressure difference is average or extreme, however, depends on the building.
Regards,
 David



On 3/16/2011 08:25, 王洋 wrote:


Dear Mr. Bradley,

     But I cann't find the ASHRAE Handbook of Fundamentals about
  the Conduction Transfer Function methodology. My ASHRAE Handbook of Fundamentals is 2009 version.
The chapter 4 Heat transfer and Chapter 6 Mass transfer have no informations about transfer function coefficients.
Please tell me which chapter of the ASHRAE Handbook of Fundamentals contains transfer function coefficients etc.?

PLUS: In Test Data Option of TRNFLOW : about the pressure difference(pa). Please tell me normally what's the pressure differnce between outside and inside in winter or summer? The trnflow manual and Example Rest_com.tpf have no detailed introduction. I tried also 20 pa or 0 pa etc. Is it OK?

Many thanks!

Br.

wang





>
>
>  Wang,
>   The thermal time constant for a zone in your building is not a simple
> thing to compute. It has to do with the materials in the wall, the
> placement
> of the mass within the wall, the capacitance of the zone, ventilation,
> infiltration, gains, solar radiation, etc. I would think that the easiest
> way to get an estimate of the zone's thermal time constant is to impose a
> step change in one input on it - step change the ambient temperature while
> holding all other inputs constant for example.
>
>   The numbers that you see in the *.inf file are transfer function
> coefficients. You can read in the ASHRAE Handbook of Fundamentals about
> the
> Conduction Transfer Function methodology.
> Regards,
>  David
>
>
>
> On 11/3/2010 09:29, 王洋 wrote:
>
> Dear all,
>
> 1. How to calculate or find the thermal time constant of zone in TRNSYS
> software?
>
> ---------- WALL TYPE BST_FL_HEAT_W1      ----------
>
>        THERMAL CONDUCTANCE, U=    67.80000 kJ/h m2K; U-Wert=     4.48235
> W/m2K
>               (incl. alpha_i=7.7 W/m^2 K and alpha_o=25 W/m^2 K)
>
>                         TRANSFERFUNCTION COEFFICIENTS
>    K            A              B              C              D
>
>    0       1.7050117E+02    2.1087019E+01    1.7050117E+02
> 1.0000000E+00
>    1      -1.1800059E+02    3.5808933E+01   -1.1800059E+02
> -1.3683139E-01
>    2       6.0267372E+00    1.6298573E+00    6.0267372E+00
> 4.7362566E-05
>    3      -1.2736107E-03    2.3363784E-04   -1.2736107E-03
>   SUM      5.8526043E+01    5.8526043E+01    5.8526043E+01
> 8.6321597E-01
> What's meaning of A B C D? Are they Wall's TRANSFERFUNCTION COEFFICIENTS?
> And what is the thermal time constant of the whole zone? How to calculate
> or
> find the thermal time constant of the whole zone in TRNSYS software?
> Need I   calculate by myself the whole zone's TRANSFERFUNCTION based on
> all
> the walls of the zone or others?
>
> 2.  How to calculate or find air volume flow of the window opening in
> TRNFlow software?
>  The window opening area (m2)is known. Whether it needs the wind
> speed(m/s)
> or not?
>
> Many thanks!
>
> Br.
>
> wang
>  2010/11/3 <trnsys-users-request@cae.wisc.edu>
>
>> Send TRNSYS-users mailing list submissions to
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>> Today's Topics:
>>
>>   1. Re: GenOpt optimization: problem for the second generation
>>      after 5 simulations (Thibaut VITTE)
>>   2. Re: google sketchup+trnsys3d (hotline)
>>   3. input file (Emiliano Casati - 3ME)
>>   4. Re: GenOpt optimization: problem for the secondgeneration
>>      after 5 simulations (Timothy McDowell)
>>
>>
>> ---------- 已转发邮件 ----------
>> From: Thibaut VITTE <thibaut.vitte@h3c-energies.fr>
>> To: trnsys-users@cae.wisc.edu
>> Date: Wed, 03 Nov 2010 11:27:53 +0100
>> Subject: Re: [TRNSYS-users] GenOpt optimization: problem for the second
>> generation after 5 simulations
>> Dear Alexis,
>>
>> I've had a similar error when I used Genopt. I've had several components
>> tracked by a "trace" command that made my list file enormous (more than
>> 100Mb) and genopt could'nt handle that amount of data.
>>
>> Just my 2cents.
>>
>> Thibaut
>> --
>>
>> Le futur maîtrisé
>>
>>  Thibaut VITTE
>>
>> Docteur - Ingénieur Energies
>>
>> Mail : thibaut.vitte@h3c-energies.fr
>>
>> -----------------------------
>>
>> H3C-énergies
>>
>> 35, chemin du vieux Chêne - 38240 MEYLAN
>>
>> Tél : 04 76 41 88 66 – Fax : 04 76 41 28 94
>>
>> www.h3c-energies.fr
>>
>>
>> -----------------------------------------------------------------------------------
>>
>> Afin de contribuer au respect de l'environnement, merci de n'imprimer ce
>> message qu'en cas de nécessité.
>>
>> In order to respect the environment, please don't print this e-mail
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>> ---------- 已转发邮件 ----------
>> From: "hotline" <hotline@transsolar.com>
>> To: "julia.feste" <julia.feste@whitepavilion.com.cn>
>> Date: Wed, 3 Nov 2010 11:37:08 +0100
>> Subject: Re: [TRNSYS-users] google sketchup+trnsys3d
>> Hi,
>>
>> that's a well known problem that will be fixed in the next version.
>> Hopefully upcoming within the next weeks.
>>
>> Regards
>> Christian
>>
>> TRANSSOLAR Software Team
>> hotline@transsolar.com
>>
>> www.trnsys.de
>> Transsolar KlimaEngineering - Technologien für energieeffizientes Bauen
>> und Nutzerkomfort in Gebäuden
>> Transsolar Energietechnik GmbH, Curiestrasse 2, 70563 Stuttgart /
>> Amtsgericht Stuttgart - HRB 23347 / USt-IdNr.: 99073/00911
>> Geschäftsführer: Dipl.Ing. Matthias Schuler, Dipl.Ing. Thomas Auer,
>> Dipl.Phys. Stefan Holst, Prof. Volkmar Bleicher
>>
>> -----Ursprüngliche Nachricht-----
>> Von: julia.feste [mailto:julia.feste@whitepavilion.com.cn]
>> Gesendet: Mittwoch, 3. November 2010 06:46
>> An: trnsys-users@cae.wisc.edu
>> Betreff: [TRNSYS-users] google sketchup+trnsys3d
>>
>>
>> Hello everybody,
>> Thanks for your posts that's always really interesting!
>> I come up with a problem using Google Sketchup and TRNSYS3D: inside a
>> TRNSYS zone, I draft a square, then I want to pull it up at a certain
>> height, so I write the number then Enter, and this error appears:
>>
>> <-----Beginning of the error----->
>> ERROR:
>> NoMethodError
>> undefined method `position' for
>> #<Sketchup::AttributeDictionary:0xfcb4eb8>
>>
>> BACKTRACE:
>> C:/Program Files/Google/Google SketchUp
>> 8/Plugins/Trnsys3d/sketchup/Sketchup.rb:309:in `polygon_loop'
>> C:/Program Files/Google/Google SketchUp
>> 8/Plugins/Trnsys3d/sketchup/Sketchup.rb:309:in `each'
>> C:/Program Files/Google/Google SketchUp
>> 8/Plugins/Trnsys3d/sketchup/Sketchup.rb:309:in `polygon_loop'
>> C:/Program Files/Google/Google SketchUp
>> 8/Plugins/Trnsys3d/sketchup/Sketchup.rb:321:in `outer_polygon'
>> C:/Program Files/Google/Google SketchUp
>> 8/Plugins/Trnsys3d/sketchup/Sketchup.rb:326:in `polygon'
>> C:/Program Files/Google/Google SketchUp
>> 8/Plugins/Trnsys3d/lib/interfaces/DrawingUtils.rb:27:in
>> `detect_base_face'
>> C:/Program Files/Google/Google SketchUp
>> 8/Plugins/Trnsys3d/lib/interfaces/DrawingUtils.rb:20:in `each'
>> C:/Program Files/Google/Google SketchUp
>> 8/Plugins/Trnsys3d/lib/interfaces/DrawingUtils.rb:20:in
>> `detect_base_face'
>> C:/Program Files/Google/Google SketchUp
>> 8/Plugins/Trnsys3d/lib/interfaces/BaseSurface.rb:254:in `face_polygon'
>> C:/Program Files/Google/Google SketchUp
>> 8/Plugins/Trnsys3d/lib/interfaces/BaseSurface.rb:253:in `each'
>> C:/Program Files/Google/Google SketchUp
>> 8/Plugins/Trnsys3d/lib/interfaces/BaseSurface.rb:253:in `face_polygon'
>> C:/Program Files/Google/Google SketchUp
>> 8/Plugins/Trnsys3d/lib/interfaces/Surface.rb:107:in
>> `update_input_object'
>> C:/Program Files/Google/Google SketchUp
>> 8/Plugins/Trnsys3d/lib/interfaces/BaseSurface.rb:94:in
>> `update_input_object'
>> C:/Program Files/Google/Google SketchUp
>> 8/Plugins/Trnsys3d/lib/interfaces/DrawingInterface.rb:353:in
>> `on_change_entity'
>> C:/Program Files/Google/Google SketchUp
>> 8/Plugins/Trnsys3d/lib/observers/FaceObserver.rb:32:in `onChangeEntity'
>> C:/Program Files/Google/Google SketchUp
>> 8/Plugins/Trnsys3d/lib/AsynchProc.rb:17:in `initialize'
>>
>> <-----End of the error----->
>>
>> When I pull it up manual, I don't have any problem, just when I write
>> the number.
>>
>> Thanks in advance for your help,
>> Julia.
>> ________________________________________
>> From: trnsys-users-request@cae.wisc.edu
>> [trnsys-users-request@cae.wisc.edu]
>> Sent: Wednesday, November 03, 2010 1:04 AM
>> To: trnsys-users@cae.wisc.edu
>> Subject: TRNSYS-users Digest, Vol 71, Issue 4
>>
>> Send TRNSYS-users mailing list submissions to
>>        trnsys-users@cae.wisc.edu
>>
>> To subscribe or unsubscribe via the World Wide Web, visit
>>        https://www-old.cae.wisc.edu/mailman/listinfo/trnsys-users
>> or, via email, send a message with subject or body 'help' to
>>        trnsys-users-request@cae.wisc.edu
>>
>> You can reach the person managing the list at
>>        trnsys-users-owner@cae.wisc.edu
>>
>> When replying, please edit your Subject line so it is more specific than
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>>
>>
>>
>>
>>
>>
>> ---------- 已转发邮件 ----------
>> From: "Emiliano Casati - 3ME" <E.I.M.Casati@tudelft.nl>
>> To: <trnsys-users@cae.wisc.edu>
>> Date: Wed, 3 Nov 2010 13:19:58 +0100
>> Subject: [TRNSYS-users] input file
>>
>> Hi to everybody!
>>
>> I don’t understand why, for certain projects, I can’t open the input
>> file,
>> the message is “the system cannot find the path specified”.
>>
>> Where should I find the input file?
>>
>>
>>
>> Thanks a lot
>>
>>
>>
>> ec
>>
>>
>> ---------- 已转发邮件 ----------
>> From: "Timothy McDowell" <mcdowell@tess-inc.com>
>> To: "Thibaut VITTE" <thibaut.vitte@h3c-energies.fr>,
>> trnsys-users@cae.wisc.edu
>> Date: Wed, 3 Nov 2010 07:23:05 -0500 (CDT)
>> Subject: Re: [TRNSYS-users] GenOpt optimization: problem for the
>> secondgeneration after 5 simulations
>> This type of error in GenOpt is usually caused by an error in the TRNSYS
>> simulation.  You need to check the *.lst file for the TRNSYS run to see
>> what the TRNSYS error is.
>>
>> Regards,
>>
>> Tim
>>
>>
>>
>>
>>
>> ----------------------------------
>> Timothy McDowell
>> Executive Vice President
>> Thermal Energy System Specialists, LLC
>> 22 N. Carroll St, Suite 370
>> Madison, WI 53703
>> Phone: 608-274-2577
>> Fax: 608-278-1475
>>
>> ----- Original Message -----
>> From: "Thibaut VITTE" <thibaut.vitte@h3c-energies.fr>
>> Sent: Wed, November 3, 2010 5:27
>> Subject:Re: [TRNSYS-users] GenOpt optimization: problem for the
>> secondgeneration after 5 simulations
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>    Dear Alexis,
>>
>>    I've had a similar error when I used Genopt. I've had several
>>    components tracked by a "trace" command that made my list file
>>    enormous (more than 100Mb) and genopt could'nt handle that amount of
>>    data.
>>
>>    Just my 2cents.
>>
>>    Thibaut
>>    --
>>
>>
>> .bodyclass      @page { size: 8.5in 11in; margin-top: 0.7874in;
>> margin-bottom:
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>> margin-top:0in;
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>> margin-top:0in;
>> font-family:Tahoma, sans-serif; text-align:justify ! important;
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>> margin-top:0in;
>> font-family:Tahoma, sans-serif; text-align:justify ! important;
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>> margin-top:0in;
>> font-family:Tahoma, sans-serif; text-align:justify ! important;
>> color:#3329b1; font-style:italic; }
>> .bodyclass      .P8 { font-size:7.5pt; margin-bottom:0in;
>> margin-top:0in;
>> font-family:Tahoma, sans-serif; text-align:justify ! important;
>> color:#3329b1; font-style:italic; }
>> .bodyclass      .P9 { font-size:12pt; margin-bottom:0in; margin-top:0in;
>> font-family:Times New Roman; text-align:justify ! important; }
>> .bodyclass      .P91 { font-size:12pt; margin-bottom:0in;
>> margin-top:0.05in;
>> font-family:Times New Roman; text-align:justify ! important; }
>> .bodyclass      .Standard { font-size:12pt; font-family:Times New Roman;
>> }
>> .bodyclass      .T1 { color:#f79646; }
>> .bodyclass      .T2 { color:#f79646; font-family:Tahoma, sans-serif;
>> font-size:7.5pt; }
>> .bodyclass      .T3 { color:#3329b1; font-family:Tahoma, sans-serif;
>> font-size:7.5pt; }
>> .bodyclass      { }
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>                  Le futur maîtrisé
>>
>>
>>
>>
>>
>>
>>
>>              Thibaut VITTE
>>              Docteur - Ingénieur Energies
>>              Mail : thibaut.vitte@h3c-energies.fr
>>
>>              -----------------------------
>>              H3C-énergies
>>              35, chemin du vieux Chêne - 38240 MEYLAN
>>              Tél : 04 76 41 88 66 – Fax : 04 76 41 28
>>                  94
>>              www.h3c-energies.fr
>>
>>
>>
>>
>>
>>
>>
>>
>>  -----------------------------------------------------------------------------------
>>      Afin de contribuer au respect de l'environnement,
>>        merci de n'imprimer ce message qu'en cas de nécessité.
>>      In order to respect the environment, please don't
>>        print this e-mail unless you really need to.
>>
>>
>>
>>
>>
>>
>> _______________________________________________
>> TRNSYS-users mailing list
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>>
>> ----- End of original message -----
>>
>>
>>
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> listTRNSYS-users@cae.wisc.eduhttps://www-old.cae.wisc.edu/mailman/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@tess-inc.com


-- 
***************************
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



-- 
***************************
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@tess-inc.com

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