Marco Simonetti

A Numerical and Experimental Study of an Air Device for controlled Natural Ventilation of a building

Abstract The rationale of an advanced natural ventilation system should be to control airflows and air temperature during winter, and to avoid unnecessary energy losses and local draught, while maintaining an adequate ventilation rate. On the other hand, natural driving forces (pressure head due to buoyancy and wind) vary significantly during the heating season. A prototype of a new device for controlled natural ventilation of buildings has been designed with the aim of avoiding cold draughts and excessive energy consumption during the coldest periods as well as ensuring the right amount of airflow even during mid-seasons. The device has been numerically studied by means of a commercial Computational Fluid Dynamics (CFD) code and has subsequently been built and experimentally tested. The CFD calculations were validated and used to assess the practical possibility of controlling the very low airflow rates typical of natural ventilation. Results will be used to investigate the comfort conditions in a room equipped with such a device during a normal heating season.

Thermodynamic modelling of an adsorption chiller based on a zeolite

Low power adsorption chillers with low desorption temperatures deserve particular attention, because of the possibility of driving them with a solar thermal system integrated with buildings. The monitoring of a recent solar cooling installation in Turin, Italy, has pointed out the opportunity of developing a dynamic mathematical model, in order to simulate the transient performances of this plant. Focusing on the aforementioned low power-low temperature adsorption chiller category, this work proposes a numerical model of the systems, that include a novel zeolite as the adsorbent and water as the refrigerant fluid. The simulation results have been verified by means of the nominal values of one of the very few commercial chillers of this typology available on the market, and have compared with experimental data found in the literature for similar plants.Copyright