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Da: Bettina Nocke
[mailto:bettina@dream.unipa.it] Dear TRNSYS User’s, using the Integrated Model for Chilled Ceiling Panels
I’m not able to resolve some problems. My questions are: a) if I define only internal walls (test room for cooling
panels), how let I know the model the geometrics of the room (perpendicular
walls etc.)? b) can I define the emissivity of the internal
surfaces? (prEN 14240 stipulates an emission rate at least 0.9) c) the coefficients const and exp (Properties) are
done for the condition Tsurfceiling ? Tairceiling < 0. but so I have to
apply the exponent for a negative value. It means only the amount, without
sign? ? d) For calculate αconv with equation
6.3.2-157, the constant is done in KJ/m^2K, but multiplying with delta T,
remains KJ/m^2. I’m not sure if I understand rightly the units, so I have a
problem to change the default values (for achieve in the simulatione the same
results as the test of radiant panels). e) is the same model suited to be used for a heating
ceiling? The results of my simulation seems a little bit strange… I want to add another question
at the mail of yesterday: In the energy balance
output, in the cooling case, gains (SQCSURF) AND energy flows to other surfaces
(QCOMO, QCOMI) have a negative value. This is a little bit confusing for me,
for understand the convective and the radiative part of energy changes (setting
identical all boundary temperatures). Can anybody help me? Thanks very much. Bettina |