AC condition system

This older refrigerant called R 12 boils at what temperature ?

-21.64 F degrees below zero

The sensitivity of the electronic leak detector is ———————- per year.

0.15 ounce per year (4grams/year)

The maximum moisture content allowable in new refrigerant is ————-

10 ppm

In Denver, Colorado, water (H2O) boils at a temperature of —————

206.2°F (96.78°C) .

This tool is used to check cars AC system presures.

AC Gage set.

An air-conditioning system that uses a fixed orifice tube has a(n) ———— in the suction line.

Accumulator

____________states that the volume of a gas varies inversely with the absolute pressure at a constant temperature.

Boyle's Law

A unit of heat measure is the_______thermal unit.

British

___________states that the volume of a fixed mass of gas held at a constant pressure varies directly with a change in absolute temperature.

Charles' Law

This part of some AC systems energizes and de-energizes to cause the Compressor to work.

Compressor Clutch

This refrigerant is a substitute to standard AC systems is know as .

Drop in or Alternative refrigerant mixture .

Moisture becomes vapor by the natural process of_______

Evaporation

_______exert pressure in all directions and will completely fill any container that holds them.

Gases

When the pressure of R-134a is high, the temperature will be ———. When the pressure is low the temperature will be ——-

High , low

This is the state of refrigerant as it leaves a reciever drier in a cars AC system

High Pressure Liquid

This is the state of refrigerant and pressure as it leaves the Compressor.

High Pressure gas or vapor.

This is the pressure and state of refrigerant leaving the condensor is ?

High pressure liquid

This part measures outside air temperature to prevent compressor clutch engagement when A/C is not required or when compressor operation might cause internal damage to the seals and other parts.

IAT or Ambiant Air Temp sensor

The metric conversion of pounds (weight) is________

Kilograms (kg)

_______ heat cannot be felt or measured with the use of a thermometer

Latent

What is the state and pressure of refrigerant as it leaves the expansion valve or orfice tube ?

Low Pressure Liquid.

This is the state of refrigurant as it leaves the accumulator

Low presure vapor.

This is the part in the Cars AC system that caures a split in presure.

Orfice Tube or Expansion valve or (TXV)

Humidity in the passenger compartment can be increased by many factors, including but not limited to, hot muggy days, rainy days, and even———- in the vehicle contributing to humidity load by ——————

Passenger, breathing

This switch is electrically connected in series with the compressor electromagnetic clutch. Like the thermostatic switch, the turning on and off of the pressure cycling switch controls the operation of the compressor.

Pressure Cycling Switch .

This refrigerant was used for many years in cars after R12 and before R1234yf.

R 132A

This gas causes Green House effect if used in cars AC systems.

R 134A

This gas is the latest refrigerant installed in late model vehicles from the factoryin AC systems

R-1234yf

An air-conditioning system that uses a thermostatic expansion valve has a(n) ————. in the liquid line.

Receiver -dryer

The temperature at which refrigerant vaporizes or condenses is the ——— temperature.

Saturation

This tool is used to determain if sealants are used in vehicles .

Sealant Kit

Latent heat is required to cause a change of____________

State

The full name for R-1234yf is

Tetrafluoropropene

This part of a recovery machine is resposable for boiling the moisture out of the system

Vacuum pump.

Technician A says that the component identified by B is an evaporator. Technician B says that the component identified by A is a condenser. Who is correct? A only b. B only c. Both A and B d. Neither A nor B

a. A only

Technician A says that the ideal superheat for an automotive air-conditioning system is 10-20°F. Technician B says that flash gas is a contributing factor of superheat. Who is correct? a. A only b. B only c. Both A and B d. Neither A nor B

a. A only

Technician A says the condenser is a heat exchanger for the superheated refrigerant in the system. Technician B says the accumulator is a heat exchanger that removes heat from the air flowing across the evaporator cooling fins. Who is correct? a. A only b. B only c. Both A and B d. Neither A nor B

a. A only

Vacuum pump efficiency is being discussed. Technician A says that vacuum pump efficiency is greatest at sea level. Technician B says that altitude has little or no effect on vacuum pump efficiency. Who is correct? a. A only b. B only c. Both A and B d. Neither A nor B

a. A only

What is the state of the refrigerant as it immediately enters the evaporator, line 1? Technician A says it is all liquid with some flash gas. Technician B says it is all vapor. Who is correct a. A only b. B only c. Both A and B d. Neither A nor B

a. A only

What is the state of the refrigerant in line 4? Technician A says that it is high-pressure vapor. Technician B says that it is high-pressure liquid. Who is correct? a. A only b. B only c. Both A and B d. Neither A nor B

a. A only

The compressor is connected to the drive pulley by a: a. Electro-magnetic clutch b. Clutch diode c. Electro-mechanical clutch d. Mechanical clutch

a. Electro-magnetic clutch

One of the functions of the air-conditioning compressor is to increase the pressure of the refrigerant. Another function of the compressor is to: a. Increase the heat (temperature) of the refrigerant b. Increase the volume of the refrigerant c. Increase the vaporization point of the refrigerant d. Pump the liquid refrigerant

a. Increase the heat (temperature) of the refrigerant

Everything in nature contains what type of heat? a. Specific heat b. Latent heat c. Sensible heat d. Natural heat

a. Specific heat

All of the following are important properties that an automotive refrigerant must exhibit except: a. The refrigerant must be highly stable and allow for repeated use without decomposing or changing its properties. b. A refrigerant must be explosive or flammable. c. The critical temperature of the refrigerant must be higher than the condensation temperature of the system. d. Evaporator pressure must be higher than atmospheric pressure.

b. A refrigerant must be explosive or flammable

Technician A says that the component identified by A is a receiver-drier. Technician B says that the component identified by D is a condenser. Who is correct? correct? a. A only (if the illustration depicts a thermostatic expansion valve [TXV] system) b. B only c. Both A and B d. Neither A nor B

b. B only

What component is shown as C? Technician A says that it is an accumulator. Technician B says that it is a receiver-drier. Who is correct? a. A only b. B only c. Both A and B d. Neither A nor B

b. B only

What is the purpose of the desiccant? Technician A says it is to clean the refrigerant. Technician B says it is to dry the refrigerant. Who is correct? a. A only b. B only c. Both A and B d. Neither A nor B

b. B only

What type of heat transfer requires air movement? a. Radiation b. Convection c. Conduction d. Evaporation

b. Convection

All of the following are processes by which heat moves, except: a. Radiation b. Latent c. Conduction d. Convection

b. Latent

An R134a recovery tank pressure is determined to be 115 psig at 85°F. What does this temperature-pressure relationship indicate? a. The recovery tank is contaminated with moisture. b. The recovery tank is contaminated with air. c. The recovery tank is overcharged. d. The recovery tank is at normal operating pressure.

b. The recovery tank is contaminated with air.

Which of the following statements identifies the correct state and pressure of the refrigerant throughout the system? a. The refrigerant is low pressure at points 1, 2, and 3 in the system and high pressure at points 4, 5, and 6 in the system. b. The refrigerant is low pressure at points 1 and 5 in the system and high pressure at points 2, 3, 4, and 6 in the system. c. The refrigerant is high pressure at points 1, 2, and 3 in the system and low pressure at points 4, 5, and 6 in the system. d. The pressure varies from high pressure to low pressure throughout the system, depending on heat loads.

b. The refrigerant is low pressure at points 1 and 5 in the system and high pressure at points 2, 3, 4, and 6 in the system.

This tool is used to check for AC system leaks if a leak detector cannot find it .

black light and UV dye.

The metering device changes high-pressure liquid to: a. A low pressure b. A high pressure c. A low-pressure liquid d. Any of the above, vapor depending on the outside air vapor temperature

c. A low-pressure liquid

Fluorescent leak detector scanner solution is being discussed. Technician A says after being introduced into the system, it cannot be removed. Technician B says an ultraviolet light is required for detecting a leak. Who is correct? a. A only b. B only c. Both A and B d. Neither A nor B

c. Both A and B

Heat transfer is being discussed: Technician A says that heat flows from a hot surface to a surface containing less heat. Technician B says that heat leaves the body by the process of evaporation. Who is correct? a. A only b. B only c. Both A and B d. Neither A nor B

c. Both A and B

Technician A says that a sight glass is often found in an R-12 system. Technician B says that a sight glass is seldom found in an R-134a system. Who is correct? a. A only b. B only c. Both A and B d. Neither A nor B

c. Both A and B

Technician A says that latent heat is hidden heat and cannot be measured on a thermometer. Technician B says that latent heat is hidden heat that is required for a change of state of matter. Who is correct? a. A only b. B only c. Both A and B d. Neither A nor B

c. Both A and B

Technician A says that service ports may be a source of leaks. Technician B says that hose connections are sometimes a source of leaks. Who is correct? a. A only b. B only c. Both A and B d. Neither A nor B

c. Both A and B

Technician A says that the line or hose that connects the compressor outlet to the condenser inlet is called the discharge line. Technician B says that the line or hose that connects the evaporator outlet to the compressor inlet of a TXV system is called a suction line. Who is correct? a. A only b. B only c. Both A and B d. Neither A nor B

c. Both A and B

Technician A says the compressor is one of the points in the air-conditioning system where there is a separation between a high and a low pressure. Technician B says the metering device is one of the points in the air-conditioning system where there is a separation between a high and a low pressure. Who is correct? a. A only b. B only c. Both A and B d. Neither A nor B

c. Both A and B

The acceptable comfort range for the human body is: a. 72°-80°F b. 45-50 percent relative humidity c. Both A and B d. Neither A nor B

c. Both A and B

What is the state of the refrigerant in line 5? Technician A says that it is low pressure. Technician B says that it is a vapor. Who is correct? a. A only b. B only c. Both A and B d. Neither A nor B

c. Both A and B

All of the following are factors that affect body comfort except: a. Relative humidity. b. Air movement. c. Concentration. d. Temperature.

c. Concentration

All of the following are gas laws, except: a. Dalton's Law b. Boyle's Law c. Darwin's Law d. Charles' Law Hide Feedback

c. Darwin's Law

What is the temperature and state of the refrigerant as it enters the compressor? a. High pressure vapor b. High pressure liquid c. Low pressure vapor d. Low pressure liquid

c. Low pressure vapor

R-134a, when used as a refrigerant, exhibits a predictable relationship between pressure and temperature, and a stable change of state point between a liquid and a gas under various pressures and temperatures. All of the following are true of the temperature pressure relationship of R-134a except: a. Refrigerant in the vapor (gaseous) state can make a change of state to a liquid by increasing the pressure on the refrigerant without changing its temperature. b. Refrigerant in the vapor (gaseous) state can make a change of state to a liquid by decreasing the temperature of the refrigerant without changing its pressure. c. Refrigerant in the liquid state can make a change of state to a gas (vapor) by increasing the pressure on the refrigerant without changing its temperature. d. Refrigerant in the liquid state can make a change of state to a gas (vapor) by increasing the temperature of the refrigerant without ch

c. Refrigerant in the liquid state can make a change of state to a gas (vapor) by increasing the pressure on the refrigerant without changing its temperature.

The most accurate method for measuring the effectiveness of system evacuation is with the use of a: a. Kelvinometer. b. Micrometer. c. Thermistor vacuum gauge. d. Mercury (Hg) vacuum gauge.

c. Thermistor vacuum gauge.

A ————- type of leak warrants the use of a dye trace solution

cold or slow

The ———— is one of the points in the air-conditioning system where there is a separation between high and low pressure.

compressor

The ———— is a heat exchanger for the superheated refrigerant in the system.

condenser

This is the part in the Cars AC system that exchanges heat from inside the car to ouside the car

condensor

This is the part in the Cars ACsystem that separates gas to liquid

condensor

In a normally operating system, the refrigerant is in different physical states (vapor or liquid) at the various sections of the system. All of the following are physical states the refrigerant would be found in at various specific locations except: a. A low-pressure vapor at the suction line b. A low-pressure vapor and liquid at the evaporator c. A high-pressure vapor at the discharge line d. A high-pressure liquid at the condenser

d. A high-pressure liquid at the condenser

Refrigerant system air contamination may be caused by: a. Refrigerant system low-side leak. b. Improper system evacuation or insufficient evacuation time. c. Weak evacuation pump. d. All of the above

d. All of the above.

What is a material called that can block the flow of heat? a. A conductor b. A convectant c. A radiant d. An insulator

d. An insulator

The heat added to a vapor causing it to become warmer is called what? a. Sensible heat b. Superheat c. Latent heat d. Both A and B

d. Both A and B

The high temperature refrigerant leaving the compressor is cooled in the _________. a. Evaporator b. Radiator c. Orifice Tube d. Condenser

d. Condenser

To address the issue of small capacity refrigerant systems, the EPA adopted a new SAE standard effective December 2007, covering the accuracy level of future refrigerant recovery, recycling, and recharging equipment. The SAE number for this new standard is: a. J1850. b. 2197. c. J2210. d. J2788.

d. J2788.

What is the temperature and state of the refrigerant as it enters the evaporator? a. Low pressure vapor b. High pressure liquid c. High pressure vapor d. Low pressure liquid

d. Low pressure liquid

Technician A says that an overcharged system will result in lower than normal low-side pressures. Technician B says that an overcharged system will result in a slight increase in cooling capacity, but only under low load conditions. Who is correct? a. A only b. B only c. Both A and B d. Neither A nor B

d. Neither A nor B

Technician A says the fixed orifice tube can vary the amount of refrigerant allowed to flow to the evaporator. Technician B says the thermostatic expansion valve has a fixed opening and cannot vary the amount of refrigerant allowed to flow to the evaporator. Who is correct? a. A only b. B only c. Both A and B d. Neither A nor B

d. Neither A nor B

All of the following are forms of heat transfer that take place as it relates to the vehicle air conditioning system except: a. Convection b. Conduction c. Radiation d. Perspiration

d. Perspiration

Moisture removal from a refrigerant system is being discussed. The length of system evacuation time required depends on all of the major factors listed below except: a. The amount of moisture in the system. b. The ambient temperature. c. The efficiency of the vacuum pump. d. The amount of oil in the system.

d. The amount of oil in the system.

Under normal operating conditions all of the following occurs inside the evaporator, except: a. The refrigerant absorbs heat. b. Heat entering the refrigerant causes it to change state. c. The refrigerant removes heat from the outside air drawn across the evaporator core. d. The refrigerant changes from a vapor to a liquid

d. The refrigerant changes from a vapor to a liquid.

Contaminated or cross-contaminated refrigerant can cause system and equipment damage and present————— problems if you are not aware of its presence

diagnostic

This is the part inside the dash of a car that is responsibe for collecticting the heat from inside the car and moving it to the condensor .

evaporator

This sensor measures the temperature of the cool air immediately after the evaporator. This input to the A/C control module is used to detect evaporator freeze-up

evaporator temperature sensor.

The symbol ————— (English) is used to denote a vacuum pressure.

for mercury (Hg)

Moisture in the air is known as_______

humidity

A ————— acid is formed by the chemical combination of refrigerant and moisture

hydrochloric

Air in the refrigerant system is considered a —————— because at no time are refrigerant system pressures great enough or temperatures low enough to cause air to condense into a liquid.

non-condensable gas

An air-conditioning system —————- is an initial test that determines whether the refrigerant system is operating as designed

performance test

There is a direct relationship between temperature and ————- in an automotive air-conditioning system

pressure

This tool is used to remove remaaining refrigerant from a cars AC system .

recovery machine ,and or tank.

The amount of heat required to raise 1 lb. (0.45 kg) of matter 18F is called its __________

specific heat

Two types of metering devices are the ————- valve and the fixed———— tube

thermostatic expansion, fixed orifice

In cycling clutch systems, this part is placed in series with the compressor clutch circuit so it can turn the clutch on or off. It de-energizes the clutch and stops the compressor if the evaporator is at the freezing point.

thermostatic switch

When evacuating a refrigerant system, it should be placed under a ————- for a minimum of —— minutes to ensure moisture removal from the system.

vacuum, 30

The refrigerant changes from a ————— to a ———- in the condenser.

vapor (or gas),liquid