Hvac, acr

Hi, I am working with a Pharmaceuticals company, at present we want to develop a new floor for solid dosage product. The floor should comply U.S. FDA pharmaceuticals regulation for solid dosage product. We are little confused as we have Licensee of F.Hoffman-La Roche Ltd. and their requirements for HVAC, air change rate is not less then 6.

Can anyone give me the U.S FDA guideline for HVAC system (specially air change rate) solid dosage product or any suggestion?

Please look ISPE baseline Guide for Oral solids.