Using isothermal full-scale experiments and 3-dimensional CFD simulations it is investigated how normal office furniture influences the air movements in a mixing ventilated room. Two different types of inlets are used in the experiments and a set-up with normal office furniture is made. The set-up is simulated with one of the inlets where a volume resistance represents the furniture. The jet under the ceiling is investigated and it is found that the normal office furniture does not influence the air movements in the upper part of the room.
An application of the systemic approach is presented for the study of the ventilation of a room in an industrial facility. First, a series of tracer gas experiments was made with a radioactive tracer. Analysis of the Residence Time Distribution (RTD) curves, supported by some CFD, then enabled to build a simple zonal model for the description and quantification of the observed air flow patterns. This model was able to reproduce the experimental RTDs inside the room as well as at the exhaust.
Working spaces in modem buildings are easily formed by interior partitions because these buildings have been designed and constructed as open spaces for flexibility. This could lead to an indoor environment which might be different from the intended design. In this study, the effect of partition on the indoor air quality in a model room has been investigated with different configurations such as the height of' partition and the gap between partition and floor.
There are many indices to evaluate the ventilation characteristics of the ventilated rooms. These indices are classified into air change efficiency and contaminant removal effectiveness. In order to know how to use many indjces for a good understanding of the characteristics of the concerned ventilation system, the values of various efficiencies under some typical air flow conditions with isothermal condition are compared. The local mean age distributions and local contaminant concentrations are measured with tracer gas technique in a scaled model of the room ventilated mechanically.
Several new scales have been developed to quantify fresh air diffusion and contaminant dispersion in ventilated spaces. The local purging effectiveness is proposed for analyzing the individual contribution of each supply opening for a multi-inlet system. The local specific contaminant-accumulating index is defined to indicate the tolerance of a ventilation flow to contaminants. Furthermore, the regional purging flow rate, Up, is re-embodied in a simple expression different from the previous description.
A three-dimensional mathematical model to solve the mixing, displacement and vortex ventilation systems in the removal of pollutants with a thermal source is described. The study carried out to investigate the effectiveness of each of the individual ventilation systems showed that the vortex ventilation system performed better than the other two systems in providing moderate occupancy thermal comfort but very effective in purging pollutants away from a typical office room environment
The paper presents a mathematical model, implemented in a general computer code, that can provide detailed information on velocity and temperature fields as well as pollutants concentrations prevailing in three-dimensional buildings of any geometrical complexity, for given external meteorological conditions. The model involves the partial differential equations governing flow and heat transfer in large enclosures containing heat sources. Turbulent flow is simulated and buoyancy effects are taken into account.