There are a number of methods available concerning with distribution of air in buildings. Within control research, one can find new control algorithms which have not yet been used in practice. These new algorithms open the possibility of developing andimplementing of new demand controlled ventilation systems.In a building the internal air motions are due both to differences in temperature andpressure differences caused by the ventilation system.
This paper deals with the interzonal air movement in a building, throughhorizontal openings, under natural convective conditions. These airflow phenomena areinvestigated experimentally, through a series of experiments in the stairwell of a full-scalebuilding, using tracer gas technique. The resulting time-dependent concentration evolutionoffers a means of analyzing the flow field. These cases are also simulated by a CFD code, thatuses the finite-volume method and incorporates a low-Reynolds k-E two equation turbulencemodel.
The paper deals with energy consumption and heat recovery in office buildings with natural ventilation. Net energy consumption for ventilation is calculated for 7 European countries. The calculations are done with various air flow rates and occupancy. The calculations shows differences between the seven countries, but the net ventilation heat loss is substantial for all. Norway and Sweden will benefit most from heat recovery. Several heat recovery concepts for natural ventilation are presented.
The multiple spaces equation of ASHRAE Standard 62-1989 makes it possible to bring in a smaller fraction of outdoor air than that dictated by the critical space. This paper develops an analytical proof that increasing the primary airflow rate to t e critical space reduces the outdoor airflow rate required to meet ventilation requirements. For systems employing fan-powered boxes, where more than one box is critical, a systematic procedure for incrementally increasing the primary air is currently required.
A purpose of this research work is to study the environmental control in large indoor stadiums which utilize the natural ventilation. In these problems, effects by the airflow in and around the stadium should be analyzed. In this research work, a numerical analysis technique which enables simultaneous simulation of indoor airflow and the airflow around buildings was developed adopting composite grid coordinate calculation technique. In this paper, an outline of this technique is described.
This paper presents a new technology for capture and containment testing in commercial kitchen ventilation research. It is called large-scale focusing schlieren system and offers a nonintrusive approach to effluent flow observation. Schlieren systems can be added to conventional kitchen ventilation research laboratories or other hood testing facilities and allow continuous observation of a large area around a hood-appliance setup.
This paper presents results of applying the capture and containment test procedures in ASTM Fl 704-96, Standard Test Method for Performance of Commercial Kitchen Ventilation Systems, to determine the threshold capture and containment exhaust flow rates for a number of cooking appliances and two types of kitchen exhaust hoods.
In the design of natural ventilation systems, there is a wide range of possibilities with regard to the selection of window type and the positioning of windows in the facade. Each window type has unique characteristics, which affect air flow and thermal comfort conditions in the occupied zone. A combination of various window types and faade locations in a room should be capable of improving thermal comfort and minimising draught risk.
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