Comfort and energy performance of a HVAC system under real conditions for an office block

In the present work, we performed a dynamic simulation of an air-conditioning system for an office block using a mathematical model via Matlab-Simulink. Both the accomplishment of the desired human comfort within the conditioned space and the variation of energy request due to different measurements of volume flow rate have been evaluated, as requested by the European regulation EN 13779 on non-residential buildings. The model has been applied to an office block located in Bologna (Italy), but can also be used for other types of buildings, as well. The HVAC system in the study uses external air supply, with either constant or variable flow rate, and includes three different ways of air treatment: heating and humidification in winter, cooling and dehumidification in summer, and ventilation only, other ways. The study estimated: i) the conditions that can ensure the requested performances at the lowest energetic cost; ii) the energetic gain deriving from the installation of a heat recovery, or/ and using carbon dioxide sensors within the conditioned space. The calculation of the energy required has been evaluated in both a typical winter and summer day.