Some flow patterns within ventilation strategy coupled to energy efficiency

Abstract

Energy and buildings are increasingly becoming subjects for investigations, especially for the indoor air quality domain coupled to energy demand. The physics of fluids flowing inside enclosures bring basic models to understand and build better schemes. This paper is devoted to studying ventilation strategies in regards to Indoor Air Quality (IAQ) and energy efficiency in floor refreshing houses. A room model is considered in a simplified level, as a cavity heated on the external sidewall and cooled on the bottom ground surface. The external air injector is at variable positions and interacting with the needed cooling power; the air quality (mixing ability) and thermal comfort are also studied. The cooling efficiency inside the considered volume and the average air temperature are analyzed for a given temperature difference characterizing the natural convection level (Rayleigh number, Ra = 106) and a horizontal ventilation (moderate Reynolds number Re = 102). An obtained complex flow structure indicates that the natural convection and the forced flow (ventilation) act directly on the resulting patterns, mixing ability, heat exchange which in a straight line affect the thermal comfort and in fine the energy cost (cooling requirement).