The Energy Balance Model: Heatinging And Heating Structure

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II. Energy balance model
The methodology adopted has been used to predict the heating and cooling requirements of different buildings. Energy needs, expressed in Kilowatt-hour (kWh) are given commonly by equation 1: (01)
In the heating season, equation 1 is simplified as follows: (02)
In the cooling season, equation 1 is transformed into the following form: (03)
During inter-seasons periods, if the heat generated by energy sources (lights, occupants and their activities) is higher than the energy consumption due to the envelope, the heating and cooling needs are calculated as follows: (04)
In the opposite case, if the diffusion heat is lower than the energy consumption due to the envelope, energy needs are calculated using formula 5: (05)
II.1. Energetic
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l defines the length of the thermal bridge according the various links lpb_i/m_j: low floor i - wall j lpi_i/m_j: intermediate floor i - wall j lph_i/m_j: top floor i - wall j lmen_i/m_j: shear wall i - wall j lrf_i/m_j: shear wall i - wall j (14) hsp: the average ceiling height
N: number of habitable space niv: number of levels
The ventilation of buildings requires a minimum flow which must be ensured in order to avoid discomfort. Air leaks in the heated space increase the incoming flow rates. Therefore, the leakage in building envelope plays a major role in thermal losses. The loss coefficient generated by the air exchange system, in W/K, is calculated by the following formula [21]: (15) qveq : the equivalent volumetric flow rate of the air, transiting in the volume space (m3/h)
0.34 : the volumic thermal capacity of the air (Wh/m3 K)
If one or more flows are not used, its values are zero. (16) qvwind_aer is the aeration air flow rate when windows are used as a hygiene ventilation system (for each room). (17)
Dhyg is the hygiene flow

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