AC TQ Prep

Question 1

What should you do when filling refrigerant from zero to 100?

Answer 1

Make sure you turn it on when it’s 50% full.

Question 2

What is latent heat (Hidden Heat)?

Answer 2

Latent heat is the amount of heat required to change the state of a substance without changing its temperature.

Question 3

What is a micron?

Answer 3

A micron is a measurement equal to one-one millionth of a meter.

Question 4

What is sensible heat?

Answer 4

Sensible heat is the heat required to produce a change in temperature of a substance but not change its state.

Question 5

How can you detect sensible heat?

Answer 5

The intensity can be detected by a thermometer or by touch.

Question 6

What is relative humidity?

Answer 6

Relative humidity is the amount of moisture in air compared to the amount of moisture the air would hold at the same temperature if it were saturated full of water.

Question 7

What is critical temperature?

Answer 7

Critical temperature is the highest temperature at which a gas may be liquefied.

Question 8

What is saturation temperature?

Answer 8

Saturation temperature is a condition of both pressure and temperature at which both liquid and vapor can exist in the same container simultaneously.

Question 9

What is critical pressure?

Answer 9

Critical pressure of a liquid is the pressure at which a liquid will remain a liquid no matter how much heat is applied to it.

Question 10

What color is the vacuum hose?

Answer 10

The vacuum hose is black.

Question 11

What types of ACR copper tubing are available?

Answer 11

Type K (thick wall), Type L (thin wall), Type M (red).

Question 12

What is R22?

Answer 12

R22 is a hydrochlorofluorocarbon (HCFC) with low chlorine content and low ozone depletion potential.

Question 13

What are the basic components of an AC system?

Answer 13

Compressor, evaporator, condenser, liquid metering device, piping.

Question 14

What is the atmospheric pressure at sea level?

Answer 14

14.7 lbs per square inch.

Question 15

What does 1 BTU change?

Answer 15

1 BTU changes 1 pound of H2O 1°F

Question 16

What reduces the capacity of an outdoor condenser?

Answer 16

Temperature.

Question 17

What are the three types of condensers?

Answer 17

Water cooled, air cooled, and evaporative.

Question 18

What is temperature a measure of?

Answer 18

Temperature is the measure of the intensity of heat of a substance and the measure of its molecular speed expressed in degrees.

Question 19

What is subcooling?

Answer 19

Subcooling is defined as a liquid that has been cooled below the boiling (condensing) temperature at a specified pressure.

Question 20

What is superheat?

Answer 20

Superheat is defined as a vapor heated to a temperature above its saturation point after a liquid has vaporized.

Question 21

What are the three types of metering devices?

Answer 21

Capillary tube, thermostatic expansion valve, and orifice.

Question 22

What are the three types of dehumidifiers?

Answer 22

Heat pump, chemical absorbent, ventilating humidifier.

Question 23

How do dehumidifier heat pumps and air conditioning heat pumps work?

Answer 23

They work under the same principle.

Question 24

What speeds up the evacuation process?

Answer 24

Removing the stem in the Schrader valve.

Question 25

What amount of vacuum must be obtained to render the system free of refrigerant?

Answer 25

10" to 11" HG.

Question 26

What method is used for checking the refrigerant charged on a system equipped with a TXV?

Answer 26

Check proper sub-cooling for TXV systems.

Question 27

Which hoses are connected to each service valve?

Answer 27

Low side gauge (blue) to low side of system, high side (red) to high side of the system, middle is connected to inlet port or recovery unit.

Question 28

What are the four main types of electronic leak detectors?

Answer 28

Ion source, thermistor, halogen, and ultrasonic.

Question 29

What is the maximum capacity of any service or storage cylinder used for refrigerant?

Answer 29

80%, to allow for expansion.

Question 30

What does blue represent in refrigerant hoses?

Answer 30

Blue = Suction Low Pressure vapor.

Question 31

What does red represent in refrigerant hoses?

Answer 31

Red = High pressure liquid discharge.

Question 32

Where should superheat temperature measurements be taken?

Answer 32

Within 3 feet of the compressor suction connection.

Question 33

What do you need to record superheat?

Answer 33

You need the vapor line temperature (low side gauge) and the vapor line pressure (low side gauge).

Question 34

What should measured superheat be within?

Answer 34

Measured superheat should be within 2°F +/- of the superheat found on the table.

Question 35

What color is the compound gauge for the low side?

Answer 35

Blue.

Question 36

What pressure should the system be tested at?

Answer 36

125 psi to 150 psi.

Question 37

What side of the system is the evaporator considered to be on?

Answer 37

Low pressure side.

Question 38

What is the standard flange depth and door thickness for access doors?

Answer 38

1" to 1½".

Question 39

What determines the depth of a louver?

Answer 39

The depth of the louver is approximately 4".

Question 40

What determines the gauge of a damper?

Answer 40

Louvre width determines the gauge of the damper.

Question 41

What is the gas supply pressure range?

Answer 41

5.5" wc - 13" wc, manifold pressure set to 3.5" wc.

Question 42

What is the color coding for manifold gauge sets?

Answer 42

Blue for low, red for high, yellow for center manifold gauge.

Question 43

What should you not do with gauge sets?

Answer 43

Do not use gauge set on different refrigerant without purging it first.

Question 44

What should you remember about gauge usage?

Answer 44

Gauge should never be subjected to move more than 75% of their full scale range on the gauge face.

Question 45

What should you use when servicing air conditioning?

Answer 45

Labels, service fittings, and a refrigerant identifier.

Question 46

What is the minimum test period for high and low pressure?

Answer 46

2 hours.

Question 47

What are the minimum air pressures for R410a?

Answer 47

Low - 236 psig, high - 444 psig.

Question 48

What temperature range does the high limit switch open?

Answer 48

Between 180°F and 200°F.

Question 49

Where is the high pressure switch located?

Answer 49

In tubing between the discharge side of the compressor and the condensing coil.

Question 50

What are the three cycles of an air forces heat pump?

Answer 50

Heating, cooling, defrost cycles.

Question 51

What is used for measuring revolutions per minute (RPM)?

Answer 51

Tachometer.

Question 52

What does a pilot tube measure?

Answer 52

Both static and total pressure.

Question 53

What does a velometer measure?

Answer 53

Velocities (FPM) directly in the grills.

Question 54

What does an anemometer measure?

Answer 54

Velocities in the grills; two types are thermal and rotating.

Question 55

How long should FHR 2003 records be kept?

Answer 55

At least 5 years.

Question 56

What does the national action plan recommend regarding CFCs?

Answer 56

Not filling autos with CFCs after Jan 1, 2000.

Question 57

Is it okay to refill a refrigeration system with refrigerant?

Answer 57

Yes, if the system passes a leak test; but refilling with CFC refrigerants is not permitted.

Question 58

What must refrigerant containers be?

Answer 58

Refillable and recyclable.

Question 59

Is refrigerant handling certification accepted across provinces?

Answer 59

No, it is not normally accepted in another province.

Question 60

Can anyone use a photocopied certificate?

Answer 60

No, no one can use a photocopied certificate.

Question 61

What must be attached to refrigeration equipment before disposal?

Answer 61

A notice stating the date, time, name, and certificate number for the removal of all refrigerant.

Question 62

Is refrigerant handling recertification compulsory in Alberta?

Answer 62

No, it is not compulsory.

Question 63

What is reusing a refrigerant?

Answer 63

To remove it from a system, store it in an approved container, then return it to the same system.

Question 64

What is recycling in refrigerant handling?

Answer 64

The removal of a refrigerant, cleaning in an onsite processor, and then returned to the original refrigeration system.

Question 65

What is reclaiming refrigerant?

Answer 65

To reprocess recovered refrigerant as necessary to meet approved virgin specifications.

Question 66

What is refrigeration oil considered after removal?

Answer 66

Hazardous waste.

Question 67

What regulations apply to hydrochlorofluorocarbon refrigerants (HCFC)?

Answer 67

Federal Halocarbon Regulation.

Question 68

What is the fastest way to remove refrigerant from a system?

Answer 68

Removing liquid then vapor refrigerant.

Question 69

How long should leak testing records be kept?

Answer 69

5 years.

Question 70

What should certified persons place on a system once they are sure it does not contain refrigerant?

Answer 70

A 'no-refrigerant' notice.

Question 71

What is the only gas added to a system for pressure testing?

Answer 71

Nitrogen.

Question 72

What does not cause ozone layer depletion?

Answer 72

Smog.

Question 73

What is R134a and R410a classified as?

Answer 73

HFCs, which do not damage the ozone layer.

Question 74

Why do HFCs not harm the ozone layer?

Answer 74

Because they do not contain chlorine.

Question 75

What can refrigerant releases affect?

Answer 75

Both the ozone layer and global warming.

Question 76

What is a global warming concern regarding refrigerants?

Answer 76

Venting of HFCs.

Question 77

What is prohibited regarding CFC sales?

Answer 77

Selling CFCs in containers smaller than 410 kilograms.

Question 78

What is prohibited regarding CFC containers?

Answer 78

Selling CFCs in containers containing 10 kg or less.

Question 79

What is prohibited regarding HCFCs?

Answer 79

Selling, manufacturing, or importing HCFCs in containers containing 2 kg or less.

Question 80

How often must refrigerants be tested?

Answer 80

Every 5 years.

Question 81

What will happen to HCFC refrigerants after Jan 1, 2020?

Answer 81

They will not be produced, imported, or exported in or from Canada.

Question 82

What type of containers can refrigerant be purchased in?

Answer 82

Containers that are refillable.

Question 83

What must certified persons know about commonly used refrigerants?

Answer 83

Which are CFCs, HCFCs, or HFCs.

Question 84

What do CFCs contain?

Answer 84

Chlorine, fluorine, and carbon; they are now banned.

Question 85

What do HCFC refrigerants contain?

Answer 85

Hydrogen, chlorine, fluorine, and carbon; they were legislated to be phased out on Jan. 1, 2020.

Question 86

What do HFCs contain?

Answer 86

Hydrogen, fluorine, and carbon; HFC systems use polyolester oil.

Question 87

What are halons and bromines used for?

Answer 87

In fire extinguishing and contribute significantly to the depletion of the ozone layer.

Question 88

When is a triple evacuation used?

Answer 88

If the system is deemed to be dirty or wet.

Question 89

What are two reasons for performing a deep evacuation?

Answer 89

To remove moisture and non-condensable gases.

Question 90

What should be checked before obtaining the proper charge?

Answer 90

The airflow across the evaporator coil to ensure the correct cubic feet per minute (CFM). 400 to 425 is recommended

Question 91

What is the recommended CFM per ton of cooling?

Answer 91

Between 400 CFM to 425 CFM.

Question 92

What should you ensure when returning cylinders?

Answer 92

That valves are closed, protective caps are in place, and any outlet cap or plugs have been replaced.

Question 93

What is recommended regarding residual pressure in cylinders?

Answer 93

A residual pressure of at least 25 pounds per square inch (psi) should remain in the cylinder.