INVESTIGATING POSITIVE PRESSURE VENTILATION

Positive pressure ventilation was investigated. Forty-three experiments were performed on the first, second, and third floors of a three-storey brick building with wooden trusses. The objectives of the experiments were to investigate the effects of distance between fan and inlet, size and numbers of outlets, and volume of building on vent flow rates when using positive pressure ventilation. Four different fans from two different manufacturers with varying characteristics were used. Airflow through outlets was measured. The results shows that flow rate through an exhaust increases with increasing distance between fan and inlet up to some maximum value and a decreasing flow rate after this point. Also, flow rate through an exhaust decreases as volume of the structure increases. In a larger volume more leakage can be expected, thus decreasing the efficiency of positive pressure ventilation. In addition, increasing the exhaust area decreases the flow loss, thus increasing the efficiency of positive pressure ventilation. The number of exhaust openings affects the volumetric flow rate in a nonlinear manner