Solar chimneys are often used to extract air from a building by thermal stacks, while subfloor plenums are used to passively cool air before it is supplied to a building. This paper examines the overall flow pattern in buildings with both solar chimneys and subfloor plenums. For a multi-zone flow system in which each zone has only two effective openings, an analytical solution is derived. A sufficient condition for upward flows to occur is derived from the analytical solution.
Usually, the performance of fan-coils is defined and measured in the laboratories only through thermal quantities. However, comfort conditions within a room depend also on the air flow pattern determined by the appliance. Therefore, an experimental procedure to evaluate the fluid dynamic performance of fan-coils has been developed.
In order to give some guidance for the optimization of shop entrances regarding comfort and energy savings, a project was launched by the City of Zurich. The project covers field investigations in 12 shops with different entrance types, and analytical and numerical investigations (CFD)for complementary results. The emphasis of this work was on the interaction between the situation at the entrance for different technical local solutions with other factors of importance like building ventilation, building tightness and combination with other entrances.
The general strategy adopted in the development of a computational tool performing the identification of parametric models based on the Residence Times Distribution (Rm) theory is exposed. Two main aspects of the modelling procedure are presented: the structural discrimination of the various solution schemes, and the parameters estimation step. The structural model determination is solved by a stochastic procedure based on a Simulated Annealing algorithm, while the parametric identification is solved by a nonlinear deterministic procedure.
This paper presents a way of ventilating a large room so that the room can be divided into different zones by temporary vertical walls (canvas, plastic sheets etc) and with no physical ceiling. Different activities, like welding, painting or mechanical assembly, can go on inside each of these zones, unaffected by each other, as long as pollutants are extracted through designated extract openings in the outer walls. These inner, temporary walls need only reach from say 3 - 4 metres above the floor and up to some metres above the pollutants' height of equilibrium.
The results of various numerical simulations of wind induced flows through large openings in a room are presented. The study is parametric on the sizes and relative positions of the openings and the wind direction. Various grid densities have been used. Grid independency for the presented results is demonstrated. Validation of the numerical approach is performed using measurements on a test cell with a single opening. The influence of the inflow wind profile is studied. It is shown that different flow patterns are induced within the dwelling when different profiles are assumed.
A test room and measurement system were developed for the full-scale measurements of the active displacement air distribution. The room represents a 3-meter wide module of a larger hall. The requirements for the room included minimisation of the errors caused by air leaks, thermal conductance and flow obstacles. The measurement of the flow pattern is carried out with ultrasonic and thermal anemometers. Automated traversing system was built to move the sensors in the vertical symmetry plane of the room.
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