NATE Air Distribution 2

Question 1

What unit is used to measure duct air leakage during a duct leakage test?

Accepted Answer

CFM25 (cubic feet per minute at 25 pascals)

Answer

Inches WC

Answer

Grains per pound

Answer

MERV rating

Question 2

What is the recommended duct sealing material for permanent duct repairs?

Accepted Answer

Mastic sealant or metal foil tape (UL 181 listed)

Answer

Standard gray cloth duct tape

Answer

Spray foam insulation

Answer

Silicone caulk

Question 3

What MERV rating range is recommended for residential HVAC filters to balance filtration and airflow?

Accepted Answer

5–8

Answer

1–4

Answer

9–13

Answer

14–16

Question 4

What is the purpose of a plenum in an HVAC duct system?

Accepted Answer

Serve as a pressure chamber that distributes or collects air from multiple duct branches

Answer

Filter combustion gases from the airstream

Answer

House the thermostat sensing element

Answer

Provide combustion air to the furnace

Question 5

What is the maximum recommended duct velocity for residential supply ducts to minimize noise?

Accepted Answer

700–900 FPM

Answer

400–600 FPM

Answer

1,200–1,500 FPM

Answer

2,000+ FPM

Question 6

What is the effect of duct leakage in unconditioned spaces like attics and crawlspaces?

Accepted Answer

Wastes significant conditioned air to outside, dramatically increasing energy consumption and reducing comfort

Answer

Slightly increases equipment run time

Answer

Has negligible effect on system performance

Answer

Only affects humidity levels