Full coverage rate: The full coverage rate of high-efficiency filters on the vertical unidirectional flow ceiling should be above 80%. Sometimes the specification considers that above 70% is sufficient, but considering that the airtightness of the clean shed is worse than that of the general clean room, it is recommended to increase it to 80%.
Calculation formula: Since the Class 100 clean room usually requires full coverage of FFU, its layout rate can be directly considered as 80%-100% of the ceiling area. For specific calculations, you can refer to the following steps: Determine the total area AA (length × width) of the clean room Calculate the number of FFU required: N=A×full coverage rate/single FFU coverage area N=A×full coverage rate/single FFU coverage area
The requirements of the Class 1000 clean room are lower than those of the Class 100, but a high degree of cleanliness must still be maintained. Its airflow organization may not be completely unidirectional, so the FFU layout rate will be lower than that of the Class 100. The specific layout rate needs to be determined comprehensively based on factors such as the actual use of the clean room, air supply volume requirements, and pollution source distribution.
The FFU layout rate can be calculated according to the formula N=(A*H*n)/Q:
N is the number of FFU required
A is the floor area of the clean room (m²)
H is the height of the clean room (m)
n is the ventilation rate, which is generally 75 times/hour for a Class 1000 clean room (the ventilation rate can be adjusted according to specific needs)
Q is the air volume of each FFU (m³/hour)
It should be noted that these calculations are only basic theoretical calculation methods. In actual projects, it is also necessary to consider the impact of various factors such as clean room equipment layout, personnel flow, and return air method on airflow organization and cleanliness, and make appropriate adjustments to the layout rate and number of FFU.
Suzhou Pharma Machinery Co.,Ltd.
2025/07/28
Icey
