AIRFLOW FILTERS PATCH

This area shall consist of the net effective filter media area, which is exclusive of the filter frame or patch area of filter. The measurement area shall be cross sectional area of the filter face normal to the airflow.If applicable, and as agreed between the customer and supplier, the variance and standard deviation may be added to the test record.Ī: Filter face airflow velocity: Unidirectional.For room airflow velocity, the tests are normally performed at a specific work surface elevation (Normally 0.91 m (36”) above the floor).For filter face air flow velocity, the tests are performed at a distance of between 150mm to 300 mm from filter face.The location of the airflow reading in the work zone shall be as specified in the contract documents or as agreed between the customer and supplier.Measurements should be taken at the center of each grid cell.The number of measuring points should be more than the square root of 10 times the measuring plane area in square meters and should be not less than 4 points.

For air flow velocity measurements, define the measuring plane perpendicular to the supply air flow and divide the measuring plane into grid cells of equal area.Measurement of supply airflow volume is also performed to evaluate the arithmetic air exchange rate in the installation.Measurement of airflow velocity is applicable in unidirectional airflow cleanrooms or clean zones and is optional in non-unidirectional installations when the purpose of measurement is to evaluate its uniformity.

Refer Annex I (Table 1: Minimum Instrumentation requirements) The purpose of the SOP for this test is to evaluate airflow velocity and uniformity of airflow velocity in cleanrooms and clean zones.

Airflow filters