Exercise 2 Solution

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GROUP 13 De Donatis Lorenzo - 876178 Santoianni Genny, Nicole - 884523 Stucchi Simone - 874442 BEM Assignment 02_Part A - GROUP 13 Exercise description The aim of this exercise was find the sensible heat QT, QS, QV, QI, and the energy need QH,s for the building defined during the lecture, using the weather data of Hamburg, and four different density indices for people occupants related to the building use. 1° Simulation à Residential: iS=0.1 pers/m2 2° Simulation à Office: iS=0.2 pers/m2 3° Simulation à Conference room: iS=0.6 pers/m2 4° Simulation à Cafè: iS=0.8 pers/m2 Trnsys procedure 1) The first step was to import the weather data files thanks the “Type15-2” that allowed us to use the external temperature, from a weather file, to calculate the sensible heat loads and the energy needs. 2) We created a new calculator in which we defined the formulas of the sensible heat loads: - QT = A * U * (Text-Tset,int) /1000 , heat transfer by transmission - QS = ∑Ik* Awg,k * g , heat transfer due to solar radiation - Q I= is*Afloor*qi,s , heat transfer due to internal gains (only people are considered) - QV = mV,a/3600 * cpma * (Text-Tint) , heat transfer due to infiltration and ventilation - QH = -QT-QV-QS-Qi 3) We created another calculator in which we defined all the parameters needed to calculate the sensible heat loads. 4) We connected the weather data file with the calculator to obtain the dry bulb temperature from it. 5) As last step we imported in the file the “Type65b” in order to print the results on a graph. This “Type 15-2” was connected to the calculator and the weather data file in order to see the changes in the sensible heat loads in relation to the external temperature. 6) Lastly we run the analysis and with the external file created by trnsys we plotted the…