Influence of furniture arrangement on airflow distribution in open concept passive houses

Technical University of Civil Engineering of Bucharest, 021414 Bucharest, Romania

^* Corresponding author: adrian.ghiaus@utcb.ro

Abstract

This paper presents the analysis of airflow distribution in an open space room by means of CFD numerical simulation having as case study a pre-certified passive house, located in Cluj-Napoca. The ventilation system comprises two rectangular inlets, located on the floor near the glazing and six exhaust grilles of circular cross section located at the opposite side, at the kitchen's ceiling. An area of interest that represents the simulation/computation domain was selected. Numerical modeling was done through a commercial software, based on the finite element method that simulates a series of interconnected phenomena encountered in the field of applied engineering. Dry air was considered the fluid environment in the computing domain with thermo-physical properties taken from the program database. No slip boundary conditions were used for all the walls, volume flow rate of 215m³/h was specified for the inlets and exhaust nozzles were considered as open boundary. The following simplifying working hypotheses were established: stationary regime, incompressible fluid, constant temperature, isothermal jet, adiabatic system without internal heat sources, disregarding of mass forces. Airflow distribution analysis was performed for two distinct configurations: without furniture and in the presence of furniture. Simulation domain was divided into a large number of finite elements of variable size having a higher density near the boundary areas resulting tens of thousands of nodes. The purpose of the simulation was to evaluate the influence of furniture on the distribution of air currents in the occupied areas with direct impact on the occupants' comfort. Upon the comparative analysis for the two distinct cases, based on the distribution of streamlines, pressure and velocity vectors, the furniture's influence areas, the stationary areas and the air recirculation areas were identified.