Assessing cooling energy demands with the EN ISO 52016-1 quasi-steady approach in the Mediterranean area

In regarding to the buildings energy performances, the EN ISO 52016-1 introduced a new hourly calculation method to evaluate sensible and latent energy demands. Despite it representing a more reliable approach, in several countries it cannot yet be used because national extensions have to be provided at a local level for the correct application of calculation methodologies. Therefore, the quasi-steady procedure of the same EN ISO 52016-1, which uses the concept of the utilization factors for energy gains and heat transfer, has to be adopted. The latter represents a simplified method more appealing for designers due to the contained required input data and the reduced computational efforts, however it provides noticeable deviances in the cooling period, especially in buildings located in warm climates equipped with large glazed surfaces. In this study, in order to attain more reliable results, a calibration of the summer quasi-steady models was carried out, by means of the results provided by the TRNSYS software, referring to different configurations of two buildings located in different points of the Mediterranean area. By using the “black box” approach, simulations have allowed the determination of the “equivalent” energies to the steady-state conditions and a new correlation for the calculation of the gain utilization factor. The latter, in combination with a modification of the solar radiation transmitted through glazed surfaces, permit to determine accurate cooling energy requirements. In order to validate the calibrated procedure, the comparison between monthly cooling demands and TRNSYS results was carried out, observing deviances lower than 5%.