NCT Air Filtration Fundamentals & Filter Media 2

Question 1

ASHRAE Standard 52.2 is used to evaluate air filter performance primarily by measuring:

Accepted Answer

Particle size efficiency and dust holding capacity

Answer

ASHRAE 52.2 measures particle size efficiency across 12 particle size ranges and dust holding capacity to assign a MERV rating.

Question 2

What is the primary purpose of activated carbon in an air filter?

Accepted Answer

Adsorbing gaseous pollutants and odors

Answer

Activated carbon adsorbs volatile organic compounds (VOCs), odors, and other gaseous contaminants through its large porous surface area.

Question 3

As a filter loads with dust during service, what generally happens to both its efficiency and pressure drop?

Accepted Answer

Efficiency increases; pressure drop increases

Answer

As dust accumulates on a filter, the dust cake acts as an additional filtration medium, increasing efficiency, while restricted airflow increases pressure drop.

Question 4

Which filter construction type offers the greatest filter media surface area within a compact housing frame?

Accepted Answer

V-bank (V-pleat) filter

Answer

V-bank filters arrange multiple pleated packs in a V configuration, maximizing media area and dust holding capacity in a short housing depth.

Question 5

Fiberglass filter media is commonly used in low-MERV panel filters because it offers:

Accepted Answer

Low cost, low resistance, and acceptable efficiency for coarse dust

Answer

Fiberglass media is inexpensive, provides low initial resistance, and effectively captures larger airborne particles in MERV 1–4 applications.

(NCT) NAFA Certified Technician Practice Test

(NCT) NAFA Certified Technician Practice Test

NCT Air Filtration Fundamentals & Filter Media 2