Energy saving by evaporative air-cooling processes in building-envelope ventilated air spaces

The thermal behavior of a building-envelope with a ventilated air space in summer mediterranean climates was investigated in the case of an air-conditioned indoor ambient. The energy saving deriving from a forced ventilation carried out by saturated air subjected to a direct evaporative cooling along the air space was analyzed through a finite-difference simulation model, with reference to external walls of different masses, thermophysical properties and geometrical features, as well as to different ventilation and exhaust airflow rates. Results show that heat gains through the envelope significantly smaller than those relevant to air spaces ventilated by indoor air or, even more, to airtight air spaces.