Other Skilled Trades Sheet Metal and HVAC 2

Question 1

What tool is used to measure the static pressure within an HVAC duct system?

Accepted Answer

Manometer or magnehelic gauge

Answer

A manometer or magnehelic gauge measures the static pressure (in inches of water column) within ductwork to diagnose airflow restrictions and verify system performance.

Question 2

What is the purpose of a condensate drain line on a central air conditioning system?

Accepted Answer

To remove water condensed from humid air on the evaporator coil

Answer

As warm humid air passes over the cold evaporator coil, moisture condenses and drips into a drain pan — the condensate line removes this water from the system.

Question 3

What gauge (thickness) of sheet metal is most commonly used for residential HVAC trunk ducts?

Accepted Answer

24 gauge

Answer

24-gauge galvanized steel is the most common thickness for residential HVAC trunk ducts, providing adequate rigidity while remaining workable for fabrication.

Question 4

What does the acronym CFM mean in HVAC?

Accepted Answer

Cubic Feet per Minute

Answer

CFM (Cubic Feet per Minute) is the standard US measurement for airflow volume in HVAC systems, used to specify fan output, register sizing, and duct design.

Question 5

What is the minimum required clearance around an outdoor condenser unit for proper airflow and service access?

Accepted Answer

18 to 24 inches on all sides

Answer

Most manufacturers and codes require 18–24 inches of clearance around outdoor condenser units to ensure adequate airflow for heat rejection and safe service access.

Other Skilled Trades Practice Test

Other Skilled Trades Practice Test

Other Skilled Trades Sheet Metal and HVAC 2