FC FC Ductwork & Air Distribution

Question 1

What is the purpose of a static pressure test on a forced-air furnace system?

Accepted Answer

To measure airflow resistance in the duct system and verify proper system operation

Answer

To check gas pressure

Answer

To test the heat exchanger for leaks

Answer

To measure combustion air volume

Question 2

What is the maximum total external static pressure (TESP) typically allowed for a residential furnace?

Accepted Answer

0.5 inches W.C.

Answer

0.1 inches W.C.

Answer

1.0 inches W.C.

Answer

2.0 inches W.C.

Question 3

What is the primary cause of high static pressure in a residential duct system?

Accepted Answer

Restrictive air filter, undersized ducts, or excessive elbows

Answer

Oversized ductwork

Answer

A dirty heat exchanger

Answer

Low gas pressure

Question 4

Which type of duct fitting creates the least resistance to airflow?

Accepted Answer

Long-radius swept 90-degree elbow

Answer

Sharp 90-degree elbow

Answer

Square elbow with turning vanes

Answer

Tee fitting

Question 5

Return air duct sizing should be based on which primary factor?

Accepted Answer

System airflow (CFM) requirements of the equipment

Answer

Furnace BTU input

Answer

Number of supply registers

Answer

Duct material type

Question 6

What is the recommended maximum air velocity in residential supply duct main trunks to minimize noise?

Accepted Answer

700–900 FPM

Answer

400 FPM

Answer

900 FPM

Answer

1,500 FPM