Re: [TRNSYS-users] Massless layer + Very small zone

["Technical Support" <TechSupport@tess-inc.com>]

Virginie,
 I am also not sure how well Type56 models such small volumes so check
your results and make sure that you can justify them to yourself. As
for the u-values, TRNBuild adds some default coefficients for
convection and radiation to each wall when it displays the overall
u-value. However, the convection part of the heat transfer is
calculated internally while the model is running; the time-dependent
value is reported as one of Type56's optional outputs (NTYPES).
Kind regards,
 David



Technical Support Team
Thermal Energy System Specialists, LLC
2916 Marketplace Dr, Suite 104
Madison, WI 53719
techsupport@tess-inc.com

----- Original Message -----
Subject: [TRNSYS-users] Massless layer + Very small zone
From: "RENZI Virginie 217644" <virginie.renzi@cea.fr>
Date: Mon, April 21, 2008 7:02

Dear users,   I’m trying to model a small box made of aluminium (2mm thick) and in order to define the walls I used a massless layer. Thus I entered a thermal resistance (thickness divided by conductivity) for my new layer but the U-value given in the Wall Type Manager is different from my corresponding U-value. Does someone know why? Does it deal with the “combined heat transfer coefficients”? Is the U-value from the Wall Type Manager used at some point in the calculation?   I have another question, related to the size of the zone. It seems that it is not possible to enter a wall area smaller than 0.1m². Is it right? if yes, is there another way to model a very small zone?   Thanks for your help   Virginie         _______________________________________________ TRNSYS-users mailing list TRNSYS-users@engr.wisc.edu https://www.cae.wisc.edu/mailman/listinfo/trnsys-users