Submitted by Maria.Kapsalaki on Wed, 10/28/2015 - 17:20
Door operation and the subsequent passage of occupants through the doorway can cause containment failures in hospital isolation rooms. Typically hinged doors are used between the isolation room and anteroom/corridor in healthcare facilities. However, sliding doors can reduce door induced airflows through the doorway and hence effectively reduce the contaminant outflow during the door operation.
The purpose of this study was to find out the local intensity and extent of doorway draughts, the functioning of air curtains, and the variation of the neutral pressure levels in 18 industrial premises. The doorway draught can reach the whole workspace and all the employees. At the doorline, close to the doorway, the thermal conditions can be even harsher than those outside. Air curtains significantly decrease the fluctuation of the temperature at work sites, but the functioning of the same type of air curtain varied substantially between the buildings.
The aim of this study was to find out the effectiveness of equipment used to prevent cold air flows in the wind boxes of commercial buildings and super markets. Measurements were carried out in 14 buildings at the total of 42 work sites. The effectiveness of the equipment used to prevent cold air flows in wind boxes was insufficient. The measurements showed that temperature changes and air flows can reach even beyond than 10 m from the wind box and create serious local draft at work sites.
This paper presents the results of full-scale experiments in a realistic building to evaluate natural convective heat and mass transfer through doorway-like apertures under small temperature differentials. The zone-to-zone temperature differences were nominally between re and 2.5°C. Heat transfer correlations, coefficient of discharge, and thermal stratification are reported for air (Pr = 0. 71), an enclosure aspect ratio of 0.26, aperture height relative to the enclosure height in the range of 0. 75 to l, and aperture width relative to the enclosure width in the range 0.29 to 0. 79.
The use of sulphur hexafluoride (SF6), nitrous oxide (N2O) or carbon dioxide (CO2) as tracer-gases have been examined for the measurement of airflow in a two-zone environmental chamber. A series of measurements were carried out to examine airflows through a doorway under natural convection, forced convection and combined natural and forced convection. Results were compared with those predicted using the MULTIC computer program.
Inter-zone convection affects the general movements of air in a building and must be evaluated for accurate thermal zones heat and mass balance. The paper presents results of an experimental study of convective heat transfers caused by temperature difference between two zones connected by an opening of height 2. 05 m and varying width. Experiments were carried out in a full scale calorimetric chamber (5.5 m x 2.5 m x 2.5 m). Temperature differences were maintained by two active vertical walls locatedon either side of the doorway.
The subtask 2 of Annex XX (Optimization of Air Flow Patterns Within Buildings) involved a research project called "Air Flows Through Large Openings In Buildings". The scope of this project was to test the range of validity of available algorithms, and where possible to develop new ones. This paper focuses on the new interzonal airflow studies which have been carried out in this frame.