Clean Room AC

[mre212]

Dears
Please can you share me your experience and knowledge about Clean Room AC.
What type of AC to be apply ( AHU or air cooler)?
Filtration?
Duct?
This room for dairy manufacturing

Thank you

[cduque]

Hi mre212,
Clean rooms have various classifications. You can look at ISO 14644-1, AS 1386, BS 5295, Federal Standard 209E (canceled), etc. With those classifications you have the specification of the maximum number and size of particules that can be found in the ambient. Only after that you can identify the kind of instalation needed.
For example if you classify your clean room as ISO Class 5 ou less (FED STD 209E class 100), you will need an AHU and HEPA terminal filters (class H13 or H14) with vertical difusion, also prefilters and regular filters. In a room like this the maximum concentration / m3 of particules of 1 micron is 832.
The lower the class, the higher the sofistication of the HVAC instalation, also the number of recirculations por hour increase.
Normaly this kind of clean rooms are used for electronics production, pharmaceutical or medical operations.
In food production normaly it's not this kind of "cleanliness" that is used, in my life I have seen many diferent thing but never this kind of sofistication.
Anyway the use of an AHU and at least a prefilter and a medium F8 or F9 filter would be a good idea. Also a fabric insuflation duct is a good principle.
If you use only air coolers there is no positive influence in the cleanliness and the final result is totaly unknown.
This kind of specification must be indicated by the client (owner or consultant) as we can be talking of much money.
Hope to clarify a bit.

[Magoo]

Hi mre.
dairy process areas generally require positive pressure in the process area to an average of 5 pa / pascals, checked with a magnihelic gauge,to keep out flying insects etc. Prefilter air with hepa cleanable filter bags and condition air with cooling coils DX or chilled water. Add additional interior/ localized cooling as required.

[mre212]

Thank you very much for your reply
Please Is it ok if i use air cooler with chilled water as AC and one AHU with filtration( G4 and F9) for fresh air?
I mean can i get clean room (ISO Class 4 ) by this way?

Please what is the rule for number of recirculations per hour

Thank you

[Magoo]

Air flow rates dependent on structure tightness, allowing for doors and penetrations. Ultra clean rooms will have double entry doors and an air lock situation. Not usually required in dairy process areas though, adding low levels of ozone into pressurization air gives a sanitizing effect of outside air introduced. Ozone generators are simple to install injecting vapor into air stream.
I am not familiar with those ISO standards, yes use chilled water cooling for fresh air pressurization, but add additional cooling coils in the process area to maintain design temperature selected.