NATE Air Distribution 3

Question 1

What is the purpose of a zone damper in a zoned HVAC system?

Accepted Answer

Open or close to direct conditioned air to specific zones based on thermostat demand

Answer

Balance static pressure across all zones simultaneously

Answer

Filter air entering a specific zone

Answer

Modulate the blower speed

Question 2

What type of duct fitting causes the most turbulence and pressure drop?

Accepted Answer

Square elbow without turning vanes

Answer

Long-radius elbow

Answer

Straight section

Answer

Conical reducer

Question 3

What does the ASHRAE 62.2 standard address in residential applications?

Accepted Answer

Ventilation and acceptable indoor air quality for residential buildings

Answer

Duct leakage limits for new construction

Answer

Minimum equipment efficiency ratings

Answer

Duct system design procedures

Question 4

What is a bypass damper used for in a zoned duct system?

Accepted Answer

Relieve excess static pressure when zone dampers close by routing air back to the return side

Answer

Provide fresh outdoor air to the return system

Answer

Balance airflow between supply and return plenums

Answer

Control humidity in a single zone

Question 5

What is the correct method for measuring total external static pressure (TESP) on an air handler?

Accepted Answer

Measure static pressure in the return plenum before the coil and in the supply plenum after the coil, then subtract return from supply

Answer

Measure only at the supply plenum

Answer

Average pressures at all supply registers

Answer

Measure velocity pressure at the blower inlet

Question 6

What is the recommended insulation R-value for ducts installed in unconditioned attics in most US climate zones?

Accepted Answer

R-8

Answer

R-4

Answer

R-6

Answer

R-11