Which kind of filter will be used in hvac system for operation theater & which kind of pressure is required for this room?

HEPA filter (MERV17 & above) of0.3 microns having efficiency of99.997% are used for operation theaters. These rooms must be designed for positive pressure differential of0.01 in WC/2.5 Pa (that requires200–400 cfm offset) as per ASHRAE's Healthcare Design Manual.

ventilation filters are used and the pressure should be maintained such that the aerosols what is released should not impure the clean room.the pressure should be maintained high