HVAC Duct System Quiz

What is the purpose of automatic fire dampers in vertical ducts?

• To minimize the turbulence in the ducts

• To reduce the temperature of the ducts

• To maintain the required rating of fire-related barriers

• To increase airflow in the ducts

How often should automatic fire dampers be inspected and tested?

• Only when a fire occurs

• Once every 2 years

• At least once a year

• Once every 6 months

What is the hour rating requirement for fire dampers passing through a firewall?

• 25% of the hour rating for the wall

• 50% of the hour rating for the wall

• 75% of the hour rating for the wall

• Equal to the hour rating for the wall

Which type of fire dampers are used in duct systems with little or no airflow when the damper closes?

• Passive fire dampers

• Static fire dampers

• Dynamic fire dampers

• Automatic fire dampers

What is the purpose of using long-radius elbows in duct systems?

• To increase turbulence

• To reduce the efficiency of the ventilation system

• To decrease airflow velocity

• To minimize turbulence and maximize airflow velocity

Which manual is used to determine residential duct sizes according to the International Residential Code (IRC)?

• Manual D—Residential Duct Systems

• Manual C—Residential Duct Systems

• Manual B—Residential Duct Systems

• Manual A—Residential Duct Systems

What is the first step in sizing a duct system?

• Obtain room-by-room heating and cooling load calculations

• Calculate the design friction rate for the system

• Prepare a rough sketch of the duct system

• Obtain blower data for the equipment

What is used to determine duct sizes for each section of ductwork?

• Duct velocity chart

• Pressure drop chart

• Psychrometric chart

• Airflow friction chart

What do airflow friction charts graph?

• Pressure drops and air velocities

• Duct diameters and pressure drops

• Airflow rates and pressure losses due to friction

• Duct diameters and airflow rates

What do sophisticated software programs based on Manual D standards allow HVAC duct designers to do?

• All of the above

• Input duct routing and generate a cost estimate

• Input building configurations and generate a floor plan

• Input heating and cooling loads and generate a bill of material