COMMERCIAL AIR FILTERS AND SOUND CONTROL

Question 1

An earthly matter smaller than 100 microns would describe:

Answer 1

Dust

Question 2

A micron is a unit of linear measure. There are_________microns in one metre ?

Answer 2

1 000 000

Question 3

Filtering media of fibre screen, wire mesh, expanded metal stamping or plates coated with an oily substance would best describe:

Answer 3

Viscous impingement filter

Question 4

To be classed as a high efficiency filter, a dry media filter must have a dust spot efficiency greater than :

Answer 4

40%

Question 5

A two stage precipitator is another name for a:

Answer 5

Electronic air cleaner

Question 6

The viscous impingement filter uses the_________effect to force the rapidly moving contaminant particles to strike the filter media

Answer 6

Centrifugal

Question 7

What are the two methods of measuring dust concentration before and after the filter

Answer 7

Dust spot test

Weight test

Question 8

Spray type air washers should never be installed on the suction side of the fan unless they have been built for this purpose

T or F

Answer 8

False

Question 9

The more efficient type of air washer is the?

Answer 9

Cell type

Question 10

An effective and economical means of removing odour or gaseous contaminants is to
use a?

Answer 10

Activated carbon filter

Question 11

What product is used in between machinery and ductwork to reduce the noise transfer into the ductwork?

Answer 11

Flexible duct connectors

Question 12

The direct transmission of sound from one opening to another through the ductwork itself would define:

Answer 12

Cross talk

Question 13

To improve arrestance, some filters are coated with an adhesive. This type of filter should be referred to as:

Answer 13

a viscous impingement filter

Question 14

To prevent the vibration from a floor mounted fan from being transferred to the floor, you could use:

Answer 14

Rubber mounts

Question 15

Allergy particles from weeds, trees, flowers, and other forms of vegetation would describe:

Answer 15

Pollen

Question 16

Dry media type air filters are most efficient at:

Answer 16

Low air filtration velocities

Question 17

Noise attenuation is important on both sides of the duct system

T or F

Answer 17

True

Question 18

What are some options to attain proper noise reduction ?

Answer 18

Silencers,
fan isolation mounts,
inertia bases,
flexible connectors
acoustic liner,
sound traps

Question 19

List four types of isolator options available for centrifugal fans?

Answer 19

Free standing,

restrained spring,

housed spring,

rubber in shear

neoprene mounts

Question 20

Are springs colour-coded and why ?

Answer 20

Yes to identify their load capacity

Question 21

What material is used on the interior of a silencer?

Answer 21

Foam,
vinyl barriers
fibreglass

Question 22

Where are flexible duct connectors used?

Answer 22

Attached to equipment that contains a fan or a blower

Question 23

Can duct liners be used for kitchen exhaust?

Answer 23

No

Question 24

What is the amount of adhesive coverage required when installing duct liners

Answer 24

100% coverage

Question 25

When is metal nosing used on duct liners?

Answer 25

When velocities exceed 4000fpm

Question 26

What is the function of internal duct liner

Answer 26

To reduce noise transfer and dampen sound

Question 27

Are viscous impingement filters coated, if they are, what is the coating?

Answer 27

Oily tackifiers

Question 28

What does the acronym MERV stand for?

Answer 28

Minimum effiency reporting value

Question 29

What is the name of the gauge used to measure the pressure differential across filters?

Answer 29

Magnehelic gauge

Question 30

Which type of filter is used for odours and gaseous contaminants?

Answer 30

Activated carbon filter

Question 31

Name the two stages of an electronic air cleaner ?

Answer 31

Charging section and collecting section

Question 32

What stage of an electronic air cleaner uses ionizing wires with a positive charge

Answer 32

First stage

Question 33

What are two common methods of filter effiency testing?

Answer 33

Dust spot and weight test

Question 36

What is designed to provide air duct thermal insulation, noise absorption and vapour barriers all in one product

Answer 36

Micro-air ducts

Question 37

What’s the most important variable in all air cleaning

Answer 37

Particle size

Question 38

Ozone generators produce ozone by design T or F

Answer 38

True

Question 39

How many volts causes an induction of a strong electrostatic field into the media?

Answer 39

3000 to 6000 volts dc

Question 40

What are the two types of air washers

Answer 40

Spray type Cell type

Question 41

What is the most efficient air washer

Answer 41

Cell type

Question 42

What type of filter is the flat rectangular filter

Answer 42

Straining type

Question 43

NFPA Standard 90A: "Requires filters to be renewed or cleaned when the resistance to airflow has increased to two times the original resistance T or F

Answer 43

True

Question 44

What gauge is used to determine when filters need to be replaced

Answer 44

Magnehelic gauge

Question 45

What’s supplied in pairs and is designed to run the full length of the EQUIPTMENT

Answer 45

Isolation rails

Question 46

What is added to inertia bases on site

Answer 46

Concrete

Question 47

Where additional lateral support is required what isolator is used

Answer 47

Housed spring isolator

Question 48

What are sound absorbing materials in silencers held in by

Answer 48

Perforated metal liners

Question 49

A sound absorber should not be located immediately after a duct elbow or divided flow fitting T or F

Answer 49

True

Question 50

The transmission of mechanical equipment noise through ductwork is known as ?

Answer 50

Breakout noise

Question 51

Sound that gets into the duct from the surrounding area and transmits before breaking out is known as?

Answer 51

Break in noise

Question 52

Round ducts are less effective acoustically as they tend to be more rigid and absorb less sound T or F

Answer 52

True