David and Joke,
the coupling airflows between
two airnodes belonging two different zones are defined by adjacent surfaces
(walls/windows).
Coupling airflows between
two airnodes of the same thermal zone can be defined in the regime. A new
button coupling becomes active.
Concerning the false
ceiling problem of Joke, do you use the detailed radiation modes?
I assume not because you
do have a shading and the distribution isn’t that important anymore,
right?
If you use standard
radiation mode I suggest that your airnode “false ceiling”
doesn’t cover the whole
Ceiling area, but only 70
%. The remaining separating vertical surface between the airnode false ceiling
and room
could be defined as a
resistance wall with a high conductivity.
Virtual surfaces are
defined in Trnsys3D, but they don’t exist in the thermal model. Thus no
heat transfer through the virtual surface
can be calculated.
Virtual surfaces are defined for creating closed volumes for airnodes such that
the volume calculation of the airnode
is performed correctly.
Best,
Dipl.-Ing.
Marion
Hiller
TRANSSOLAR:
KlimaEngineering - Technologien für energieeffizientes Bauen und Nutzerkomfort
in Gebäude
Munich - New York - Stuttgart + 49.711.67976.0
Transsolar Energietechnik GmbH,
Curiestrasse 2, 70563 Stuttgart
Amtsgericht Stuttgart - HRB 23347, Steuernummer 99073/00911, USt-IdNr.:
DE152272639
Geschäftsführer:
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Von: David BRADLEY [mailto:d.bradley@tess-inc.com]
Gesendet: Dienstag, 18. Oktober
2011 19:28
An: Joke De Beuckelaer
Cc: TRNSYS-users
Betreff: Re: [TRNSYS-users]
Simulation of false ceiling: influence on inertia
Joke,
This came up yesterday as well (how to make a coupling air flow across a
virtual surface) and I unfortunately don't know the answer. I am looking into
it and will let you know what I learn.
Best,
David
On 10/18/2011 11:23, Joke De Beuckelaer wrote:
David,
Thanks for the answer. But the problem is that it isn't a
100% false ceiling but about 70%.
So what do I do with the "air - air contact"
between the two zones.
Does Trnsys takes this into account when I model it with a
virtual surface in google sketchup or do the airnodes then have to belong to
the same thermal zone?
Greetings,
Joke
Van: David
BRADLEY [d.bradley@tess-inc.com]
Verzonden: maandag 17 oktober 2011
18:38
Aan: Joke De Beuckelaer
CC: TRNSYS-users
Onderwerp: Re: [TRNSYS-users]
Simulation of false ceiling: influence on inertia
Joke,
I like to simulate this situation as two thermal zones; the conditioned
zone below and the plenum zone above. Because the suspended ceiling basically
has no mass to it, I simulate it as a wall made up of a single purely resistive
(ie massless) layer.
best,
David
On 10/14/2011 03:44, Joke De Beuckelaer wrote:
Dear all,
Can anyone help me what’s the
best way to simulate a suspended false ceiling?
The goal is to simulate a class room
where the comfort is assured by using night ventilation. However for acoustic
reasons we need a false ceiling.
I want to know the percentage of
suspended false ceiling is possible in order to have still enough inertia from
the concrete ceiling.
Is the best way just to define two
different types of ceiling (1. A concrete ceiling and 2.a false ceiling
(concrete + air layer + false ceiling)) or has anyone another idea?
Is it possible to draw for example some
obstructions in Google sketch up and then to define 3 air nodes in trnsys. One
air node above the suspended false ceiling; one air node in the middle of the
room and one air node representing the opening window?
Will it take into account the less
availability of the inertia of the concrete ceiling?
Hoping for an answer,
Joke De Beuckelaer
project engineer mep
VK HEALTHCARE | BUILDINGS | INDUSTRY |
INFRA
Value
by design
t +32 2 414 07 77 f
+32 2 414 04 98 m +32 473 97 01 50 e joke.d@vkgroup.be w www.vkgroup.be
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confidential and for the sole useof the addressee. If you are not the intended
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please immediately notify
the sender by e-mail at the address shown and then delete it from your system
without copying, disclosing or forwarding its contents. Thank you.
-- ***************************David BRADLEYPrincipalThermal Energy Systems Specialists, LLC22 North Carroll Street - suite 370Madison, WI 53703 USA
P:+1.608.274.2577F:+1.608.278.1475d.bradley@tess-inc.com
http://www.tess-inc.comhttp://www.trnsys.com