For that field study, measurements of different aspects of an UFAD (UnderFloor Air Distribution) system performance were made in an office building. The results show evidence of the benefits provided by UFAD on indoor air quality.
In this paper, the numerical methods are first validated by experiments, then a seated computational thermal manikin (CTM) is used to carry out the parameters study of Personalized Ventilation .The modeling outcome shows that in a stagnant environment, the human body is enclosed by the thermal plume and its intensity is affected by the room air temperature.To tear away the thermal plume at the windward side of the human body, a uniform airflow in the horizontal level with a O,2 m/s speed is strong enough.
The ventilation potential of buildings is widely affected by the building location, wind direction, space between buildings : so when high-rise buildings are too close, the influence of adjacent buildings on the availability of cross-ventilation has to be taken into account.
This paper reports the results of CFD simulation studies on that effect.
Filter performance of two new systems of simple respirators are investigated in this paper : a new method is used to quantify the real value of face seal leakage. The results show that respirators can't perform well because of the important leakage of airflow when they are mounted on the headform.
The study shows that physical characteristics of respirators such as the resistance and face fitting geometry are main factors to decide the leakage.
For that study, experiments are conducted to develop a new breathing ventilator using the concept of alternating-current (AC) ventilation. That ventilator is composed of a reversible fan and a thermal storage medium. In order to obtain the air change efficiency of a room by AC ventilation, numerical simulations are performed .
To face infection in hospitals, the control of the concentration of bacteria in patient rooms is necessary. For that study, computation and experiment were carried out in a real hospital isolation room. CFD software was used to simulate steady and transient air motion. A fog generated by an ultrasonic nebulizer was used to put experimental bacteria into the patient room.. The effect of bacteria removal by means of colony counts was examined. Both computational and experimental results proved that the original design of the isolation room could not remove bacteria effectively.
The aim of negative pressure control in an isolation room is to control the airflow so as to control the movement of airborne infectious particles. The differential pressure between isolation room and adjacent ambient areas should control the direction of airflow from clean to less clean areas. But operations such as the opening or closing of the door between the two areas would destroy the differential pressure.
A field study was carried out in a cold area market building. The IAQ and various kinds of factors that influence IAQ and human body 's thermal comfort were analyzed. In parallel the personnel was investigated through questionnaire. Results show that the main reason that caued poor IAQ was shortage of fresh air and insufficient ventilation.
Top Hung windows are typical and popular in North China. Measures in classrooms of Tianjin University equipped with such windows have been made. Then under different conditions, the comparison has been made with sliding windows : it appeared then that the indoor air quality was better.
Login