Unit 1

Question 1

In _________ heat or hidden heat, heat is known to be added, but no temperature rise is noticed.

Answer 1

Latent

Question 2

PSIA at sea level standard conditions is

Answer 2

14.696 / 29.9 hg (at 70 degrees F)

Question 3

The two common temperature scales used by air-conditioning and refrigeration technicians are called ___________ and ____________.

Answer 3

Celsius and Fahrenheit

Question 4

The Fahrenheit absolute scale is called the______________ scale.

Answer 4

Rankin

Question 5

Atmospheric pressure in inches of mercury (“HG) decreases ____________ per 1000 feet of increase in elevation.

Answer 5

1 HG

Question 6

Gauge that reads 0 PSI when open to the atmosphere is known as _____________ gauge.

Answer 6

Compound

Question 7

The Celsius absolute scale is called the____________ scale.

Answer 7

Kelvin

Question 8

The weight of a column of air at sea level at standard conditions is ___________ psig.

Answer 8

14.696

Question 9

Heating the vapor temperature above the boiling point is called _____________.

Answer 9

Superheat or latent heat

Question 10

Heat that changes the temperature of a substance is called _____________ heat.

Answer 10

Sensible

Question 11

What is the difference between a mercury barometer and an aneroid barometer?

Answer 11

Mercury is a liquid used that rises and falls with the pressure of atmosphere. Aneroid barometers do not use liquid to measure atmosphere.

Question 12

How many BTUs of heat are removed per hour when the water at a flow rate of 10 gallons per minute is cooled 15°F? (Water weighs 8.33 lbs per gallon)

Answer 12

74,970 btu/hr

10x60=600 gal/hr
600x8.33= 4998 lbs/hr
4998x15= 74970 btu/hr

Question 13

Define conduction of heat

Answer 13

Heat is transferred from molecule to molecule, causing molecules to move and heat to transfer. (Draw concept)

Question 14

Define radiation of heat

Answer 14

Heat that passes through air and gas and heat a surface. Example: heat from the sun that travels through the atmosphere and heats your arm.

Question 15

Define convection of heat

Answer 15

Transfer of heat via liquid or force convection. (Draw example). Pot of boiling water

Question 16

Match the temperature in Fahrenheit and Celsius to the correct equivalent Fahrenheit and Celsius temperatures. 12 total questions. Use the following equations:

Answer 16

C = (F - 32) / 1.8

F = (C x 1.8) + 32

Question 17

Match the pressures and PSA to the correct equivalent (Use 15 as the conversion between Psia and psig)

20psia

Answer 17

5 psig

Question 18

Match the pressures and PSA to the correct equivalent (Use 15 as the conversion between Psia and psig)

0 psia

Answer 18

15 Hg vac

Question 19

Match the pressures and PSA to the correct equivalent (Use 15 as the conversion between Psia and psig)

25 psia

Answer 19

10 psig

Question 20

Match the pressures and PSA to the correct equivalent (Use 15 as the conversion between Psia and psig)

85 psia

Answer 20

70 psig

Question 21

Match the pressures and PSA to the correct equivalent (Use 15 as the conversion between Psia and psig)

10 psia

Answer 21

5 “ hg vacuum

Question 22

Multiple choice:
How many BTUs are required to change one pound of ice at 20°F to steam at 220°F

Answer 22

1304 btu/h

Question 23

Multiple choice
The standard atmospheric pressure at sea level is __________.

Answer 23

29.92” Hg

Question 24

Which of the following represents a different temperature than the other three?
A. 15°C.
B. 59°F.
C. 475° kelvin
D. 519° rankin

Answer 24

C. 475° kelvin

Question 25

Multiple choice How many BTUs are required to change 5 pounds of ice at 20°F to steam at 220°F?

Answer 25

6520 Btu/h

Question 26

Multiple choice Temperature can be thought of as ________

Answer 26

A description of the level of heat

Question 27

Multiple choice Pure water boils at a temperature of 212°F, and which of the following standard conditions

Answer 27

14.696 psi

Question 28

Multiple choice As a temperature of a material increases, the molecules in the material______

Answer 28

Travel faster

Question 29

Multiple choice How many BTUs must be removed from 1 pound of water at 200°F for it to end up as ice at 30°F

Answer 29

313 Btu

Question 30

Multiple choice The temperature on the Celsius scale at which all molecular activity stops is

Answer 30

-273°C

Question 31

Multiple choice The amount of heat needed to change. The temperature of a substance will vary with the type of substance. This heat quality is called the ________ of the substance.

Answer 31

Specific heat

Question 32

T/F The difference in the level of heat between two substances will determine the heat transfer rate between the substances

Answer 32

True

Question 33

T/F The difference in the volume of two substances will determine the heat rate between the substances

Answer 33

False

Question 34

T/F When water at 212°F boils, it is only absorbing latent heat

Answer 34

True

Question 35

T/F Water at 0°F has no heat energy or molecular activity

Answer 35

False

Question 36

T/F Temperature difference does not affect heat transfer rate

Answer 36

False

Question 37

T/F The Fahrenheit scale is used in the English measurement system by the United

Answer 37

True

Question 38

T/F In order for water at 60°F to boil, it must absorb both sensible and latent heat

Answer 38

True

Question 39

T/F Water boils at 212°C

Answer 39

False

Question 40

T/F The laws of thermodynamics can help us to understand what heat is all about

Answer 40

True

Question 41

T/F Both sensible heat and latent heat transfers can be read with a thermometer

Answer 41

False

Question 42

The temperature set point for an office should be at________

Answer 42

73°

Question 43

In Hawaii department of health regulation, the temperature for a chill box should be at what temp?

Answer 43

35 to 39°F

Question 44

What are the two vents called that is in an office AC system?

Answer 44

Supply and return

Question 45

The ________ were the first store, natural ice, and snow to cool wine and other delicacies

Answer 45

Chinese

Question 46

The ancient people__________ Cool liquids in porous earth in jars. These jars were set out in the dry night air. And the evaporation from the liquid being through the porous walls providing cooling.

Answer 46

Egypt

Question 47

What company produced the compressor that was practically noise less? It had no seals and internal moving parts. Only mercury column. Compressed the refrigerant gas as the entire unit rotated.

Answer 47

Savage Arms Company

Question 48

In 1939 what compressor company introduced the first successful semiotic field serviceable compressor

Answer 48

Copeland

Question 49

Define BTU

Answer 49

Amount of heat energy needed to raise the temperature of 1lb of water 1 degree Fahrenheit