100-Class Dustless Room
According to the international standard of ISO14644 clean room: 100-class clean room equals to the fifth class.
For 100-class clean room, its flow pattern of indoor air current is vertical on-way current or level current, and the speed of the air current is: 0.2~0.5m/s. The dusty particle number is 3520/m3. Under the normal condition, when its distribution rate is 80%, the distribution rate of the vertical one-way current should be not smaller than 60%, and the distribution rate of level one-way current should be not smaller than 40%, otherwise, it will change to be partly one-way current.

The advised numbers of lower limit air speed of one-way current of clean room:
The smallest air speed to ensure that the clean room can control the following four kinds of pollution:
A. When the pollution air current multi-directionally spread, the air-supply current should be effectively control the range of the pollution;
B. When the pollution air current and air-supply air current are the same direction, the air-supply air current should be effectively control the spread range of the pollution air current reaches the lower place;
C. When the pollution air current and air-supply air current are not the same direction, the air-supply air current can control the pollution air current in the essential range;
D. Under the condition that the whole clean room is polluted, it will have enough time to clean the indoor room by itself at a suitable period.