Assessment of Indoor Air Parameters in Building Equipped with Decentralised Façade Ventilation Device

Abstract

The study contains an analysis of a decentralised unit installed in a building façade, where air supply and exhaust cycles are swapped by proper positioning of dampers. The analysis was carried out in real conditions in an office building. The Computational Fluid Dynamics (CFD) simulation is an important element of the system design, and has become more and more widely used. Simulation of the analysed unit has shown air stream distribution in a room. Moreover, it allowed for determination of indoor air temperature. Completed analysis and CFD simulations allow for the observation that façade ventilation systems provide a good way to improve the indoor microclimate, as they effectively reduce air pollution. The decentralised façade ventilation unit reduced the carbon dioxide concentration to a level lower than 1000 ppm and maintained the indoor air temperature in the range of 19.5–22 °C. The error for CFD simulation equals 0.5%, which is not much. The results of research and analysis show that the highest reduction of carbon dioxide concentration occurred when supply/exhaust time equalled 10 min. At the same time, when supply/exhaust time equalled 10 min, the indoor air temperature was the lowest of the recorded values.