Posts

Gowned lab worker under hood w TV2 on Wall

Clean Room Design & Build

/in , /by

test

Industrial Applications
Process Classification
Aerospace ISO Class 5-7
Assembly of Touch Screen ISO Class 7
Composite Materials ISO Class 8
General Industrial ISO Class 8
Injection Molded Parts ISO Class 7-8
Optical ISO Class 5-7
Electronics
Process Classification
Semiconductor ISO Class 5
SMT Assembly ISO Class 7-8
Solar ISO Class 5-7
Wafer Board ISO Class 5
Consumables and Pharmaceuticals
Application Classification
E-Liquid ISO Class 7-8
Food Packaging No Classification
Nutraceutical Packaging ISO Class 7-8
Pharmaceutical Compounding ISO Class 7
Pharmaceutical Packaging ISO Class 8
Sterile Compounding ISO Class 5
Medical Devices
Application Classification
Device Reprocessing ISO Class 7
Inplantable Devices ISO Class 5
Medical Device Packaging ISO Class 7-8

Building and designing a cleanroom requires proper planning, and a thorough understanding of the equipment and technology used in the controlled environment to ensure it’s correct and safe operation. Clean room design will be heavily dependent on the type of process that will be carried out in the space chosen.

Many companies prefer to consult with an engineer, an architect, an HVAC specialist and a general contractor before moving forward with a particular clean room design.

For the purposes of this article, we’ll get right down to the basics of best practices for optimal clean room design.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

mmmmmmmmmmmmmmmm

 

ISO 14644-1 Cleanroom Standards
Classification Maximum Particles/m3 FED STD 209E Equivalent
≥0.1µm ≥0.2µm ≥0.3µm ≥0.5µm ≥1µm ≥5µm
ISO 1 10 2.37 1.02 0.35 0.083 0.0029
ISO 2 100 23.7 10.2 3.5 0.83 0.029
ISO 3 1,000 237 102 35 8.3 0.029 Class 1
ISO 4 10,000 2,370 1,020 352 83 2.9 Class 10
ISO 5 100,000 23,700 10,200 3,520 832 29 Class 100
ISO 6 1.0 x 106 237,000 102,000 35,200 8,320 293 Class 1,000
ISO 7 1.0 x 107 2.37 x 106 1,020,000 352,000 83,200 2,930 Class 10,000
ISO 8 1.0 x 108 2.37 x 107 1.02 x 107 3,520,000 832,000 29,300 Class 100,000
ISO 9 1.0 x 109 2.37 x 108 1.02 x 108 35,200,000 8,320,000 293,000 Room Air
Zoom in of one pressure readout on partial screen of TV2

Negative Pressure in a Positive Pressure Cleanroom

/in , /by

Not too long ago we were asked by a pharmaceutical manufacture why our TV2 pressure monitor showed a negative pressure indication on the Max/Min display.

We investigated and found that if you quickly open the door into the room the pressure drops down into the negative range.  This had always been the case but he had never noticed it since he was using analog pressure monitors.  They did show the jump to negative pressure but you had to look quick since the needle swings happened fast.  The TV2 monitor, being digital, records and updates the high and low pressure, showing each in red if it is below the safety level.  So even if the room experienced negative pressure for a few seconds it is written to the display where it is very obvious.  In fact it jumps right out at anyone walking by.  That is, of course, the whole point, but this manufacturer was worried that an inspector would balk if the minimum pressure reading showed up in red.  Explaining that it was probably negative for a few seconds would not be enough to avoid ‘ding’ on the report.  Any indication of a negative pressure was a problem.  It was a problem easily fixed.  We simply set the display to not show the Max/Min.

However, this fix ignores the real problem.  Anytime the door of a positive pressurized  room is opened, all of that positive pressure air can and often does spill out into the hall where it is instantly mixed with the outside air and then sucked back into the room.  And, of course, it brings with it any and all suspended particles so that now the cleanroom is no longer clean.  Or at least as clean as it needs to be.

There are actually three solutions to this problem:  1.  Open the door verrrry slowly;  2. Install large capacity blowers that turn on any time a door is opened to maintain positive pressure; and 3.  Install a pressurized air lock so that pressure can return to positive before the door to the clean area is opened.  Each solution has its own drawback.  Option one is impractical and probably impossible to enforce.  Option two is expensive to install and may lead to increased maintenance costs.  Option three is the best solution.  In order to be effective personnel must pause in the air lock until it is re-pressurized and the in-rushing air has had time to be evacuated.  It is also important that the two doors not be opened at the same time.