|1.Reference of times of ventilation in
1)Common places request 25-30 times/ hour
2)Public places with dense people request 30-40 times/hour;
3)Workshop with heat devices request 40-50 times/hour;
4)Workshop with high temperature and bad pollution request 50-60 times/hour;
5)The southern area with wet climate request more times of ventilation, the northern area
with dry and hot climate request less times of ventilation.
2.The account method of numbers of sets
Definition of times of ventilation: Times of ventilation (times/hour)= Total amount of
indoor airflow (m3/h)/ (area of the room (m2)*height below the orifice of air-transporting
Number of sets=area of the room*times of ventilation/the amount of airflow of the set
3.As for the air transportation to positions of workers, we can
choose equipments according to the fact of the environment, and the total amount of
airflow can be decrease properly.