MEASURING TECHNOLOGY AND ASSESSMENT OF NATURAL VENTILATION APPLIED IN A COMPLEX BUILDING

By natural ventilation, the air rate varies randomly. Therefore, it is difficult to evaluate the naturalventilation performance due to insufficient measured data. In the present work a complex office buildingwas taken as a study object for the experimental investigation. A measurement technology isdeveloped in this work for the assessment of the natural ventilation performance in the building. Themeasuring sensors for temperature, moisture and airflow velocity were located along the flow-paths ofthe natural ventilation and on some other dominant positions according to the structure of the building.An assessment system is proposed for the evaluation of the utility of the natural ventilation. The air rateof natural ventilation should be evaluated according to the necessary ventilation rate. In the paper, thenecessary ventilation rate is determined by three factors: human health, indoor air quality and heatextraction. The alignment chart for the necessary ventilation rate can then be obtained. The complexbuilding discussed in the paper was tested comprehensively in May, 2005 and was evaluated by theassessment system of nature ventilation proposed. The evaluation results show that the measurednatural ventilation rates were always larger than the necessary ventilation rates, and the coefficient ofventilation effective utilization and the efficiency of ventilation exchange were always greater than 1.The air circulation ratio was 5 times per hour when the opening ratio of the lower windows was 28%.