Filtech Testing Division - Air Changes Per Hour (ACPH)

Air Changes Per Hour (ACPH)

At Filtech, we record Air Changes Per Hour (ACPH) as part of our Cleanroom Certification services, ensuring precise air quality and ventilation rates in controlled environments. Our certification process aligns with key industry standards, including USP 797, USP 800, USP 825, GMP, CETA, CAG, and ISO-14644-1.

Certification Process and Equipment

Our experienced technicians utilize calibrated equipment, including Direct Inflow Measurement (DIM) devices to accurately measure airflow volume within your controlled environments. For hard-to-reach ceiling HEPA units, we offer the ability to calculate CFM through velocity readings utilizing a Digital Anemometer or a Velgrid.

Determining Air Changes Per Hour (ACPH)

Air Changes Per Hour (ACPH) is a crucial metric for evaluating the ventilation and air quality in controlled environments. It represents the number of times the entire volume of air within a room is replaced with fresh, filtered air in one hour. ACPH is calculated using the following formula:

Air Changes Per Hour = Room CFM x 60 ÷ Room Volume in Cubic Feet

· Room CFM (Cubic Feet per Minute): This is determined by measuring the supply air volume in the ceiling HEPA filters using calibrated equipment like Direct Inflow Measurement (DIM) devices. In cases where access to ceiling units is challenging, we can calculate CFM by taking velocity readings using a Digital Anemometer or Velgrid.

· Room Volume in Cubic Feet: We measure the total volume of the room to accurately calculate ACPH

USP 797 IV Rooms

ISO 7 classified rooms require a minimum of 30 ACPH to meet regulatory standards. 15 Air Changes must be provided through the Secondary Engineering Controls, while an additional 15 Air Changes can be pulled from a Primary Engineering Control (Typically a Cleanbench or a Biosafety Cabinet) assuming the HEPA filtered air is recycled into the room.

USP 800 Hazardous Drug (HD) Compounding Rooms

These high-risk areas, also ISO 7 classified, maintain the same requirement of 30 ACPH to ensure safety and compliance.

USP 797 ISO 8 Anterooms

Adhering to ISO 8 standards, anterooms require a minimum of 20 ACPH to guarantee optimal air quality within the cleanroom suite.

HD Storage Areas

In hazardous drug storage areas, ACPH meets the requirement of 12 ACPH. Our certification process includes the measurement of exhaust volume in HD storage to ensure compliance.