Standard of ventilation times in dust-free workshop
(1) In the standards of dust-free workshops in different countries, the experience ventilation times of non-unidirectional flow dust-free workshops of the same level are not the same. China's Code for the Design of Clean Workshops (GB 50073-2001) clearly specifies the number of empirical ventilation required for the calculation of clean air supply volume in non-unidirectional flow dust-free workshops of different levels, as shown in the table below:

Remarks:
The number of ventilation is suitable for dust-free workshop whose floor height is less than 4.0m.
(2) The lower limit value should be adopted when the number of people in the room is small and the heat source is small.
(3) No less than 12 ventilation times in dust-free workshops with a scale greater than 100000.
In addition:
Laboratory Animal Environment and Facilities
National Standard GB 14925-2001
Regulations
Ordinary environment 8-10 times/h
Barrier environment 10-20
Isolation environment 20-50
(2) Temperature and relative humidity
Temperature and relative humidity in dust-free workshop (area) should be suitable for pharmaceutical production process. When there is no special requirement, the temperature should be controlled at 18 - 26 C, and the relative temperature should be controlled at 45% - 65%.
(3) Pressure difference
(1) Dust-free workshop must maintain a certain positive pressure, which can be achieved by making the supply air volume greater than the exhaust air volume, and should have a device indicating the pressure difference.
(2) The static pressure difference between adjacent rooms with different air cleanliness grades should be greater than 5 Pa, the static pressure difference between dust-free workshop (area) and outdoor atmosphere should be greater than 10 Pa, and there should be a device indicating the differential pressure.
(3) The process produces a large amount of dust, harmful substances, explosive substances and penicillins, some steroids, and any microorganisms considered to have pathogenic effects in the production process, the operating room and its adjacent rooms or areas should maintain relative negative pressure.
(4) Fresh air volume
A certain amount of fresh air should be maintained in the dust-free workshop, and its value should be taken as the Zui value of the following air volume:
(1) 10%~30% of the total air supply in non-unidirectional flow dust-free workshop and 2%~4% of the total air supply in unidirectional flow dust-free workshop;
(2) The amount of fresh air needed to compensate for indoor exhaust and maintain positive pressure;
(3) Ensure that the indoor fresh air per person per hour is not less than 40 m3.
(5) Notes on other standards:
1. Standard for Management of Sterile Medical Devices (YY 0033-2000): Frequency of ventilation in 100,000-grade clean area: Frequency of ventilation in 15/h 10,000-grade clean area: Frequency of ventilation in 20/h.
2. Rules for the implementation of in vitro diagnostic reagents: There is no specific provision, only the range of pressure difference is specified.
3. Pharmaceutical production quality management standard: There is no regulation, only the range of pressure difference is stipulated.
4. Design Specification for Clean Workshop (GB50073-2001): Frequency of ventilation in 100,000-grade clean area: 10 times/h-15 times/h 10,000-grade clean area: 15 times/h-25 times/h.
5. GMP Validation Guidelines (2000 edition) recommend: ventilation times in 100,000-grade clean areas: 15 times per hour in 10,000-grade clean areas: 25 times per hour.
6. International Standard for Biological Pollution Control (ISO14644)* Chapter Clean Grade Division: 100,000 Class Clean Zone Air Exchange Frequency: 10/h-15/h 10000 Class Clean Zone Air Exchange Frequency: 15/h-25/h.
That is to say, the number of ventilation can be discussed.
(6) Explanation of ventilation times in general clean areas: