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Question 1

Several common forms of energy are heat chemical electrical and mechanical. in the following right each blank space the appropriate form of energy

Answer 1

A - oil burned in a boiler converts it’s ( heat ) energy to. ( chemical ) energy
B - An electric motor converts ( electrical ) energy to ( mechanical ) and ( heat ) forms of energy

Question 2

Temperature- is a measure of heat intensity or quantity ? while a BTU - is a measure of heat intensity or quantity?

Answer 2

Intensity quantity

Question 3

Three states of matter are?

Answer 3

Solid Liquid and gas

Question 4

Absolute zero ?

Answer 4

-460*

Question 5

When circling water is chilled in a refrigeration machine, the sensible or latent heat of the water is changed ?

Answer 5

Sensible

Question 6

Pressure exerted by the weight of liquid at rest is called ?

Answer 6

Hydrostatic pressure

Question 7

The occupied zone in an air conditioned room extends from the floor upwards from the floor upwards a distance of ?

Answer 7

6’ ft

Question 8

The velocity of air to which occupants of air conditioning space are exposed is called local velocity or residual velocity for human comfort this philosophy should be in the range of ?

Answer 8

35 - 75 ft./min.

Question 9

Smudging of ceiling around a ceiling diffuser is probably caused by ?

Answer 9

Dirty secondary air

Question 10

Air distribution system increases comfort of the occupants by controlling?

Answer 10

Humidity temperature air motion

Question 11

Human beings can dissipate excess heat from their skin a current of air passing over the skin and removing more heat than the skin would normally dissipate is called a?

Answer 11

Draft or gross air

Question 12

In a terminal reheat system temperature or volume or both, temperature and volume is/are automatically veried ?

Answer 12

Both temperature and volume

Question 13

A group of rooms all supplied by air of the same temperature and having windows facing West can, as related to an air distribution system, be referred to as a?

Answer 13

Zone

Question 14

2 methods of static pressure control located at the supply fan are?

Answer 14

VFD and inlet guide veins

Question 15

Dry contacts

Answer 15

separate control voltage, alarms, pressure switch, building automation, cts

Question 16

Wet contacts

Answer 16

In line (powered), line voltage thermostat

Question 17

The relationship of total pressure in the duct to the static pressure and the velocity pressure is?

Answer 17

Sum of static and velocity pressure

Question 18

On impact tube with open and facing into the airstream will sense?

Answer 18

Total pressure

Question 19

A velocity pressure of 1” in wc is indictative of a duck velocity very close to?

Answer 19

4000 ft./min.

Question 20

Given a rate of air flow of 2225 CFM in a. having a cross-section of 18” by 18”, the duck velocity should be?

Answer 20

3860 ft./min. V×AREA××CFM

Question 21

The fractional resistance of a duck system is indicated by ?

Answer 21

Static pressure

Question 22

The resistance to air flow presented by cooling coil is 0.30” in wc when 2000 CFM pass through the coil the resistance will become_______ “ wc if the air quantity is increased to 3000 cfm

Answer 22

0.45” wc

Question 23

To determine on the job the direction in which a centrifugal fan is rotating you should look at the fan?

Answer 23

From the side on which the drive pulley and belt are located

Question 24

A fan delivers 2000 CFM when rotating at the speed of 1000 rpm if the fan is increased to 1200 RPM the fan will handle ?

Answer 24

2400 CFM

Question 25

You have a sheet of graph paper on which have been drawn a fan performance curve for the speed at which the fan is actually operating and a system curve from this information how can you determine the actual CFM and static pressure?

Answer 25

The point of intersection of the fan performance curve with a system curve indicates the actual CFM and static pressure

Question 26

The fractional resistance of a duck requires point 0.25” wc static pressure to cause air to flow in the duct at a rate of 2500 CFM. For flow in the same duct to be increased to 3500 CFM the static pressure will have to be?

Answer 26

0.49” wc.

Sp2

Question 27

You Have a blowthru type of airhandling unit, you are to determine the amount of sensible heat the cooling coil is removing from the air. Assuming you have already determined the air quantity in CFM you should then measure?

Answer 27

DB temperatures entering and leaving the coil

Question 28

Manufacturers fan rating tables show values of air horse power or break horse power?

Answer 28

Break horsepower

Question 29

If a centrifugal fan is rotating backwards?

Answer 29

Air will flow into the fan inlet and out of the fan discharge

Question 30

A type of the tachometer that combines a revolution counter in a stopwatch in one instrument is called a?

Answer 30

Chronometric tachometer

Question 31

A type of tachometer that uses light to obtain an indication of RPM is called a?

Answer 31

Is strobescope

Question 32

3 effects of access belt tension are

Answer 32

1. Early belt failure
2. Excessive wear on shaft bearings
3. Possible overload of a drive motor

Question 33

Any slack and a fan belt will cause?

Answer 33

1. Slippage
2. Loss of power
3. Excessive belt wear

Question 34

Several V vaults of smaller Cross-sectional area are used instead of 1B belt of large Cross-sectional area to reduce the?

Answer 34

Size of the drive

Question 35

A belt drive on a motor driven fan has a drive sheet of 3” pitched diameter on the motor the pulley on the fat and shaft has a pitched diameter of 5”. When the motor speed is 1720 RPM what is the fan speed it’s the fan speed? Hes a little one where’s a little 1 at hes a little basketball well you don’t just kick that 1 hillies look that little basketball the blue 1 no grab the blue 10K blue 10K use that 1 that whatever whatever whatever

Answer 35

W