Methodology for design and evaluation of zero energy buildings in mediterranean climate. Application to a Passivhaus with EAHE.

We discuss how the current definitions of zero-energy building should be completed with explicit descriptions of the comfort models adopted and how this could influence the design phase via a formal optimization procedure. We discuss with a concrete example the potentialities of the long term comfort indexes presented in EN15251 within this optimization procedure, problems and ways to overcome them. We present the results of a measurement campaign conducted on a Passivhaus built in Pianura Padana (Italy). In particular we discuss the performances of the earth-air heat exchanger (EAHE), based on metered data. We analyse the fulfilment of comfort category III (existing buildings) indoor thermal comfort conditions through the two years continuous measurements of air temperature and relative humidity in different zones of the building and through detailed measurements for shorter periods. The behaviour of the system envelope-EAHE, were calculated with the use of a dynamic simulation software. Metered results and outputs of dynamic simulation are compared. Dynamic simulations of the integrated model of the building and the EAHE are then used to develop optimised configurations in climates of the Centre and South of Italy through a parametric analysis of the main design and control variables. Further work is ongoing and will be reported in future papers.