[TRNSYS-users] air contact

[David BRADLEY]

Karol,
   What I have often done is to define a coupling air flow between the 
two zones, then run the simulation once with very little coupling flow 
and then once with a high airflow. The values of "low" and "high" are 
somewhat arbitrary; the idea is to make a reasonable guess as to how 
much air transfer there is. If there is no real difference in the 
simulation outputs that I care about (such as comfort or total building 
energy consumption) then I am confident that I don't have to spend much 
time thinking about what a good value would be (the model isn't 
sensitive to the value). If I find that there is a high degree of 
sensitivity then I can focus some more effort there.

   At the other end of the spectrum, you can of course implement COMIS, 
CONTAM, or TRNFlow in the building so as to get an estimate of what the 
transfer might be.
Kind regards,
  David


On 2/14/2014 12:26, Karol Bandurski wrote:
>
> Dear Jochen,
>
> Thank you for your advice, but now I am looking for the values for 
> such exchange, and the basis for this airflow assumption.
>
> What is your practice with this issue?
>
> Regards,
> Karol
>
> *From:*hotline [mailto:hotline at Transsolar.com]
> *Sent:* Friday, February 14, 2014 4:48 PM
> *To:* 'TRNSYS users mailing list at the Solar Energy Lab, UW-Madison'
> *Subject:* Re: [TRNSYS-users] air contact
>
> Dear Karol,
>
> You can merge both zones to one zone and two airnodes. Please have a 
> look into the manual 5.4.1 for the difference between airnode and zone.
>
> 1.if you draw the building in SketchUp, you need to define the wall as 
> a virtual surface, to merge them in TRNBuild ,use the 180° arrow on 
> the upper left site of the zone window
>
> 2.If you define the wall manually in TRNBuild ,you can add directly 
> another airnode to the zone.
>
> After merging you have two airnodes in the zone and you might need to 
> define an air exchange see 5.2.4.10.
>
> Best
>
> /__________________________________________________________________________________________________/
>
> //
>
> /Jochen Lam/
>
> TRNSYS Software Team
>
> /
> /*Transsolar Energietechnik GmbH*
>
> Curiestraße 2
>
> 70563 Stuttgart
>
> Fax:        +49 711 67976-11
> Email: jlam at transsolar.com <mailto:jlam at transsolar.com>
>
> Web: www.trnsys.de <http://www.trnsys.de>
>
> *Von:*trnsys-users-bounces at cae.wisc.edu 
> <mailto:trnsys-users-bounces at cae.wisc.edu> 
> [mailto:trnsys-users-bounces at cae.wisc.edu] *Im Auftrag von *Karol 
> Bandurski
> *Gesendet:* Freitag, 14. Februar 2014 15:24
> *An:* trnsys-users at cae.wisc.edu <mailto:trnsys-users at cae.wisc.edu>
> *Betreff:* [TRNSYS-users] air contact
>
> Dear All,
>
> I wondering how are you model air contact:
>
> there is two zones (e.g. two rooms) and they are connected by air 
> (e.g. doorway), there are no mechanical ventilation or intensive, one 
> direction, air flow.
>
> I think to assume some massless construction between this zones, but 
> what resistance will be appropriate? Or maybe some both direction air 
> flow, but how can I assume the value of the flow?
>
> Do you have some idea?
>
> Kind regards,
>
> Karol
>
> ------------------------------------------------
>
> Karol Bandurski MSc.
>
> Institute of Environmental Engineering <http://www.ee.put.poznan.pl/>
>
> Poznan University of Technology
>
> www.put.poznan.pl/~karol.bandurski 
> <http://www.put.poznan.pl/%7Ekarol.bandurski>
>
> www.ee.put.poznan.pl <http://www.ee.put.poznan.pl>
>
>
>
> _______________________________________________
> 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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