Installation Standards & Best Practices Flashcards

When installing HEPA filters in a critical environment, which test is performed in-place to verify filter integrity after installation?

Answer: DOP/PAO aerosol challenge scan test

An in-place DOP (dioctyl phthalate) or PAO (poly-alpha-olefin) aerosol scan test is the industry-standard method to verify installed HEPA filter integrity and detect pinhole leaks or frame bypass.

What is the maximum allowable installed filter penetration per IEST-RP-CC034 for a HEPA filter scan test?

Answer: 0.01%

IEST-RP-CC034 specifies that the maximum allowable local penetration during a HEPA in-place scan test is 0.01% of the upstream concentration.

According to NAFA guidelines, which type of duct liner should NOT be installed immediately downstream of the final filter in a critical application?

Answer: Exposed fiberglass duct liner

Exposed fiberglass duct liner downstream of the final filter can shed fibers into the clean air stream, contaminating areas the filtration system was designed to protect.

What problem occurs when a filter holding frame is installed out of plumb in a vertical filter bank?

Answer: Filters may sag, causing bypass gaps at the top or sides

An out-of-plumb frame allows filters to sag or shift under gravity, opening gaps that permit unfiltered air bypass and reduce filtration efficiency.

What is the recommended minimum overlap between a filter gasket and its mating surface on a holding frame?

Answer: 1/4 inch

A minimum 1/4-inch gasket contact with the frame mating surface ensures a reliable seal against bypass under operational static pressures.

When should a filter holding frame be cleaned before installing new filters?

Answer: Before every filter replacement to remove accumulated dirt that could compromise the new filter seal

Debris and dirt buildup on the frame seating surface prevents proper gasket compression, so the frame must be cleaned before each filter changeout to ensure a good seal.

Which installation tool is used to verify that a filter is seated with adequate and uniform compression against the frame?

Answer: Calibrated torque wrench or compression gauge on retaining clips

Calibrated retaining clip torque or a compression gauge ensures the gasket is compressed uniformly to the manufacturer's specification, preventing both under- and over-compression.