HVAC Ventilation and Air Distribution 2

Question 1

What is the purpose of a Variable Air Volume (VAV) box in a commercial HVAC system?

Accepted Answer

To vary the volume of conditioned air supplied to a zone based on its load

Answer

A VAV box modulates the volume of air supplied to a zone by adjusting a damper, allowing independent temperature control of multiple zones from a single central AHU.

Question 2

What instrument measures air velocity in a duct or at a register?

Accepted Answer

Anemometer or velometer

Answer

An anemometer or velometer measures air velocity in feet per minute (FPM), which can be used to calculate airflow volume (CFM) when combined with the duct area.

Question 3

What does MERV stand for in relation to air filters?

Accepted Answer

Minimum Efficiency Reporting Value

Answer

MERV (Minimum Efficiency Reporting Value) is a standard scale from 1-16 that rates how effectively an air filter captures particles of various sizes.

Question 4

What is duct leakage testing used to determine?

Accepted Answer

The amount of conditioned air escaping through gaps and holes in the duct system

Answer

Duct leakage testing measures how much conditioned air is lost through unsealed joints, connections, and holes in the duct system, which wastes energy and reduces comfort.

Question 5

In HVAC, what does the term 'throw' refer to when selecting supply air diffusers?

Accepted Answer

The horizontal distance the supply air travels before its velocity drops to 50 FPM

Answer

Throw is the horizontal distance that the primary air stream from a diffuser travels to reach a terminal velocity (typically 50 FPM) before mixing with room air.

HVAC - Heating, Ventilation, and Air Conditioning Practice Test

HVAC - Heating, Ventilation, and Air Conditioning Practice Test

HVAC Ventilation and Air Distribution 2