Commercial Exam Study

Question 1

NMS is national master specification is comprehensive library of construction standards

Answer 1

True

Question 2

How do you motorized zone dampers contribute to energy efficiency in residential HVAC

Answer 2

By conditioning the zones only required

Question 3

What is the purpose of a bypass damper in multi zone residential

Answer 3

To relieve pressure and prevent damage to the equipment

Question 4

What is the purpose of light commercial multi zone equipment

Answer 4

Temperature control in each zone 

Question 5

?

Answer 5

?

Question 6

Why are VAV terminals popular in light construction

Answer 6

VAV terminals all for versatility for change easy to move later 

Question 7

What is the function of a single duct terminal unit in a VAV system and where are they typically found

Answer 7

Single duct terminal units supplied condition air constant volume and temperature mostly found in interior zones

Question 8

What distinguishes Large commercial multi zone equipment from other types of zoning

Answer 8

Pressurized loops and different types of vav terminals

Question 9

How do dual duct non-mixing VAV terminals function and where are they commonly used

Answer 9

They use hot and cold ducts adjusting dampers based on temperature needs used in constant airflow like hospitals

Question 10

What are two main types of HVAC systems discussed in commercial setting

Answer 10

CAV
Vav

Question 11

What are primary types of CAv systems and How are they modified for supply temperature

Answer 11

Used in small buildings with reheat coils

Question 12

What’s the primary benefit of regular vav

Answer 12

Precise air amounts reducing consumption for smaller equipment

Question 13

Single duct vav and there temperatures

Answer 13

Volume control dampers and adjusting air flow based on zone thermostat

Question 14

How do bypass vav systems work

Answer 14

Bypass systems conditioned air without going through the occupied space. Not very efficient

Question 15

Why is make up air needed

Answer 15

Prevent negative air so there are no issue trying to open doors , backdraft from gas appliances

Question 16

Two types of gas fired makeup air units

Answer 16

Indirect
And direct

Question 17

Two types of fans and classes

Answer 17

Axial (propeller)
Centrifugal (radial )

Question 18

How dose air in axial fans work

Answer 18

Leaves the fan in the same direction it went in

Question 19

Characteristics of a propeller fan

Answer 19

Low rpm large volume of air with low static pressure

Question 20

What are cross flow fans and uses

Answer 20

They have a crossing pattern used on wall curtains for doors

Question 21

What temp is going into single duct vav box and what might be added

Answer 21

55f and a heating coil

Question 22

What are air extractors

Answer 22

Installed in main ducts where splitters can be installed

Question 23

What are some common methods for sound and noise control

Answer 23

Silencers , fan isolation mount, sound traps

Question 24

Describe CAV system

Answer 24

Supply air flow rate is constant supply air temperature is Varied

Question 25

What’s is buckling

Answer 25

Heating and cooling at the same time

Question 26

What happens to the ducts in a high velocity system

Answer 26

They are reduced

Question 27

What’s used to slow down air in high velocity

Answer 27

Attenuator

Question 28

When low temp enters system. What’s used to heat before it’s conditioned

Answer 28

Reheat coil

Question 29

Single VAV systems adjust volume of air entering the space

Answer 29

True

Question 30

Dual dock VAV system blends cold and heated air at air handling unit true or false

Answer 30

False

Question 31

Vaneaxial fans are what Efficiency

Answer 31

Most efficient

Question 32

Thousand CFM of air to remove through duct system it’s a pressure of 0.4 What motor works best

Answer 32

Forward curved blade centrifugal

Question 33

What type of blade arrangement is usually use an air pollution high particle loads

Answer 33

Radial

Question 34

The most accurate volume control air is obtain by using

Answer 34

Oppose blade dumper

Question 35

What type of isolation valves come in pairs

Answer 35

Isolation rails 

Question 36

Or additional mass is required what base do you use

Answer 36

Inertia bases

Question 37

How are free standing isolators determined

Answer 37

Colour coated coil springs to load capacities

Question 38

What is used forFloor isolators

Answer 38

Rubber

Question 39

Types of material use for acoustical lining

Answer 39

Fibreglass has become the most frequently may use material

Question 40

H

Answer 40

N

Question 41

Types of air washers

Answer 41

Spray type Cell type 

Question 42

Dry media filters increase efficiency as they collect material true or false

Answer 42

True

Question 43

What’s Merv 

Answer 43

Minimum efficiency reporting value

Question 44

When changes are made to original drawings what the changes made called

Answer 44

Revisions and addenda

Question 45

Discrepancies in drawings what take president

Answer 45

Written specifications

Question 46

What is the most note worthly Between residential and light commercial blueprints

Answer 46

Grid lines

Question 47

Where does the intersection of gridlines usually occur

Answer 47

Centreline of columns

Question 48

Which callouts are most commonly used for Hvac drawings

Answer 48

Grilling defuses 

Question 49

Who should be consulted when proposed changes

Answer 49

Design engineer

Question 50

Return air should be ducted to one or several return grill

Answer 50

Only when combustibles are present

Question 51

When duct is in conditioned space. Is it less of a factor then when it is not

Answer 51

Yes

Question 52

The most Important verible in air cleaning

Answer 52

Particle size