Nearly zero energy target and indoor comfort in Mediterranean climate: Discussion based on monitoring data for a real case study.

• The performance of "Benevento" Nearly Zero Energy Building is discussed. • The dynamic behaviour of the walls and the comfort conditions are measured. • The optimal management of the internal and external shades is evaluated. • The effectiveness of pre-treatment of ventilation air by means of geothermal probes is studied. • The hourly energy balance is analyzed with some new indexes. The paper discusses the results of a monitoring campaign performed during the spring and autumn with the purpose to evaluate the operational energy performance of an existing nearly zero energy building (nZEB). It is located in Benevento, a middle-size city of South Italy with typical Mediterranean climate. A methodology for real-time nZEB performance analysis is proposed by taking into consideration the implications of the continuous interplay between external conditions and indoor occupant requirements as well as between on-site generation and the building loads with the resulting interaction with the energy grid. It takes into account the inertial properties of building envelope and the occupant perception in term of thermo-hygrometric and visual comfort as well as of indoor air quality. Compilation and assessment of appropriate quantitative indicators are proposed basing on data with hourly time step for finding the optimal management of the internal and external shades and the ventilation system. Moreover it is discussed how daily variations can influence the efficiency of the whole building-HVAC system with particular attention to the pre-handling system based on an earth-water heat exchanger. [ABSTRACT FROM AUTHOR]