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I am modeling one apartment of a multi-family house, using identical boundary conditions for surfaces surrounding the apartment. Futhermore, I have active layers (for heating) in the floor structures below and above the apartment. Since these two floor structures are completely identical, I expect identical output results for these surfaces (temperatures and heat flow rates), but that is not the case. In attached plot, the floor surface temperature of the floor structure below the apartment (TSI_S5) is compared to the corresponding temperature for the floor structure above the apartment (TSO_S8), and there is a small deviation.
Do you have any suggestion to why this deviation occur? Can it depend on differences in surface heat transfer coefficients? I use internal calculation of these coefficients.
Thanks in advance! /Johan
@jolind Johan, I think you are likely correct that the difference is because the inside heat transfer coefficients for the floor and the ceiling are different. You can probably check the theory by looking at some of the surface outputs (NTYPE19 QCOMI - the energy transfer through the inside surface of a construction or NTYPE108 HCONVI - the convective heat transfer coefficient for the inside surface). Alternatively, you could force both surfaces to have the same (constant) convective heat transfer coefficient just as a test.
Another possibility is the distribution of beam solar. Depending on how you are handing GEOSURF, it may be that the floor of your zone is receiving more energy gains from beam solar than is the ceiling.
kind regards,
David
jolind Topic starter
11/06/2024 5:40 am
@davidbradley Thanks for your answer. I will check this. /Johan
