The lower the iso class the more stringent the requirements for keeping particles and contamination to the acceptable levels of the room class.
Iso class 1 clean room.
A cleanroom must have less than 35 200 000 particles 0 5 micron per cubic meter and 20 hepa filtered air changes per hour.
As of november 29th 2001 the federal standard 209e has been replaced with iso 14644 1.
Iso class 1 iso class 2 and iso class 3 will require 500 to 750 air changes per hour.
The particles range in size from 1 5 microns µm.
Iso 8 is the least clean cleanroom classification.
The recommended air changes per hour for an iso class 1 clean room is 500 750 and the ceiling coverage should be 80 100.
So for example an iso class 5 cleanroom has at most 105 100 000 particles per m.
Iso 14644 1 and older standard fs 209e determine class by the concentration levels of particles.
Small numbers refer to iso 14644 1 standards which specify the decimal logarithm of the number of particles 0 1 µm or larger permitted per cubic metre of air.
However class will greatly impact design considerations such as filtration hvac requirements and other design elements.
Ordinary room air is around class 1 000 000 or iso 9.
The equivalent fed standard is class 100 000 or 100 000 particles per cubic foot.
Depending on the iso class there are required averages for the number of air changes per hour.
The class defines a minimum cleanliness level not a specific design.
Iso 5 class.
Iso 14644 1 and iso 14698 are non governmental standards developed by the international organization for standardization iso.
By comparison a typical office space would be 5 10 times more dirty.
Iso 14644 1 and iso 14698.
As an example iso 8 cleanrooms also known as class 100 000 cleanrooms can be modular or soft walled and have a maximum particle count of 100 000 particles 0 5 um per cubic foot of interior air.
Iso 7 class 10 000 0 051 0 076 10 15 60 90.
The former applies to clean rooms in general see table below.
Iso 6 cleanroom class 1 000 in theory for an entire room to reach iso 6 air cleanliness you need to enter the cleanroom via an iso 8 ante room then go through an iso 7 to finally get into the iso 6 as shown in the image.
Class iso 146144 1 federal standard 209e average airflow velocity m s ft min air changes per hour ceiling coverage.
To meet requirements of a clean room as defined by federal standard 209e and newer iso standards all clean rooms must not exceed a particulate count as specified in the air cleanliness class.
Iso class 1 the cleanest cleanroom is iso 1 used in industries such as life sciences and electronics that require nanotechnology or ultra fine particulate processing.
Iso 6 class 1 000 0 127 0 203 25 40 150 240.
In reality however you can reach an iso 6 clean room with 1 recommendation is 2 airlock.