Question 1

Psychrometrics

Accepted Answer

The science and practices associated with the properties and processes involving moist air.

Question 2

Superheat

Accepted Answer

The increase in temperature of a vapor above its saturation temperature.

Question 3

Subcooling

Accepted Answer

The process of reducing the temperature of liquid refrigerant below its saturation temperature.

Question 4

Thermostatic Expansion Valve (TXV)

Accepted Answer

A device that controls the amount of refrigerant flow into the evaporator.

Question 5

Refrigerant

Accepted Answer

The substance or mixture used in heat pumps and refrigeration cycles.

Question 6

Compressor

Accepted Answer

The component in the refrigeration system that increases the pressure of the refrigerant.

Question 7

Evaporator

Accepted Answer

The component in the refrigeration system where the refrigerant absorbs heat and changes from a liquid to a gas.

Question 8

Condenser

Accepted Answer

The component in the refrigeration system where the refrigerant releases heat and changes from a gas to a liquid.

Question 9

Heat Exchanger

Accepted Answer

A device that transfers heat from one fluid to another without them mixing.

Question 10

Pressure

Accepted Answer

Enthalpy Diagram~A graphical representation of the refrigeration cycle displaying changes in pressure and enthalpy.

Question 11

Enthalpy

Accepted Answer

The total heat content of a system.

Question 12

Entropy

Accepted Answer

A measure of energy dispersion in a system.

Question 13

Specific Heat

Accepted Answer

The amount of heat energy required to raise the temperature of a substance per unit mass.

Question 14

Refrigerant Cycle

Accepted Answer

The cycle of evaporation and condensation that a refrigerant undergoes in a cooling system.

Question 15

Chiller

Accepted Answer

A machine that removes heat from a liquid via a vapor-compression or absorption refrigeration cycle.

Question 16

Heat Pump

Accepted Answer

A device that transfers heat energy from a source of heat to a destination.

Question 17

Absorption Refrigeration

Accepted Answer

A type of refrigeration where heat, rather than mechanical energy, is used to generate cooling.

Question 18

Refrigerant Charge

Accepted Answer

The required amount of refrigerant in a system.

Question 19

Refrigerant Recovery

Accepted Answer

The process of removing refrigerant from a cooling system.

Question 20

Refrigerant Leak Detection

Accepted Answer

Techniques used to identify refrigerant leaks in a cooling system.

Question 21

Desuperheater

Accepted Answer

A device used to reduce the temperature of superheated refrigerant or process steam.

Question 22

Suction Line

Accepted Answer

The line that connects the evaporator outlet to the compressor inlet.

Question 23

Discharge Line

Accepted Answer

The line that carries the refrigerant from the compressor to the condenser.

Question 24

Liquid Line

Accepted Answer

The line that carries the liquid refrigerant from the condenser to the evaporator.

Question 25

Metering Device

Accepted Answer

A device that regulates the flow of refrigerant to the evaporator.

Question 26

Capillary Tube

Accepted Answer

A type of metering device used in small refrigeration systems.

Question 27

Accumulator

Accepted Answer

A storage tank that prevents liquid refrigerant from reaching the compressor.

Question 28

Receiver

Accepted Answer

A storage tank used in a refrigeration system to store excess refrigerant from the condenser.

Question 29

Crankcase Heater

Accepted Answer

A device used to prevent refrigerant migration and condensation in the compressor.

Question 30

Oil Separator

Accepted Answer

A device that separates oil from the refrigerant.

Question 31

Sight Glass

Accepted Answer

A device that allows for visual inspection of the refrigerant condition and flow.

Question 32

Filter-Drier

Accepted Answer

A device that removes moisture and debris from the refrigerant.

Question 33

Pressure Switch

Accepted Answer

A safety device that stops the compressor if the pressure gets too high or too low.

Question 34

Differential Pressure

Accepted Answer

The difference in pressure between two points in a system.

Question 35

Vapor Compression Cycle

Accepted Answer

The most common refrigeration cycle, which utilizes a compressor to raise the pressure and temperature of the refrigerant.

Question 36

Saturation Pressure

Accepted Answer

The pressure at which a substance changes phase at a given temperature.

Question 37

Saturation Temperature

Accepted Answer

The temperature at which a substance changes phase at a given pressure.

Question 38

Dew Point

Accepted Answer

The temperature at which air becomes saturated and produces dew, representing the absolute humidity of the air.

Question 39

Wet Bulb Temperature

Accepted Answer

The lowest temperature that can be reached by the evaporation of water only, often used in psychrometrics.

Question 40

Dry Bulb Temperature

Accepted Answer

The ambient temperature as measured by a standard thermometer.

Question 41

Relative Humidity

Accepted Answer

The amount of moisture in the air compared to the maximum amount the air could hold at the same temperature, expressed as a percentage.

Question 42

Sensible Heat

Accepted Answer

The heat energy that causes a change in temperature of a substance but does not contribute to a change in state.

Question 43

Latent Heat

Accepted Answer

The heat energy that causes a change in state of a substance without changing its temperature.

Question 44

British Thermal Unit (BTU)

Accepted Answer

The amount of heat energy needed to increase the temperature of one pound of water by one degree Fahrenheit.

Question 45

Ton of Refrigeration

Accepted Answer

The amount of heat absorbed by one ton of ice melting in a 24-hour period, approximately equal to 12,000 BTU/h.

Question 46

Coefficient of Performance (COP)

Accepted Answer

The ratio of useful heating or cooling provided to work required, used to measure the efficiency of heat pumps and refrigeration systems.

Advanced Concepts for Red Seal Exam: Refrigeration and Air Conditioning Mechanic