Lesson 1 - Refrigeration and Air Conditioning Basics
Definition of refrigeration and air conditioning; Composition of matter; States of matter
Learning Objectives:– Define refrigeration and air conditioning and explain how they differ.
– Describe the two methods of lowering the temperature of a material.
– Name the three physical states of matter.
– Identify what causes matter to change its state.
Lesson 2 - Heat, Pressure, and Change of State
Heat; Temperature; Heat transfer; Sensible and latent heat; Heat quantity; Pressure; Importance of pressure in refrigeration
Learning Objectives:– Explain the difference between sensible and latent heat.
– Compare the Fahrenheit and Celsius temperature scales and convert temperatures from one to another.
– Name and describe the three methods of heat transfer.
– Define latent heat of fusion and latent heat of vaporization.
– Explain the difference between absolute pressure and gauge pressure.
– Describe the effect of pressure changes on boiling point.
Lesson 3 - The Basic Refrigeration Cycle
Vapor-compression refrigeration cycle; Refrigerant in action; Types of evaporators, compressors, condensers, and metering devices
Learning Objectives:– Explain the function of each of the major refrigeration system components: evaporator, compressor, condenser, and metering device.
– Define the terms subcooling and superheating.
– Explain the function of the refrigerant in a refrigeration system and trace its path.
– Contrast dry-expansion and flooded evaporators.
– Name the five main types of compressors.
– Define cooling medium and name the two most commonly used.
– Explain the operation of the six most common metering devices.
Lesson 4 - Air Properties and Simple Psychrometrics
Temperature; Humidity; Specific volume; Enthalpy; Psychrometric chart; Dewpoint temperature; Relative humidity
Learning Objectives:– State the definition of psychrometrics.
– List the four air properties important in psychrometrics.
– Differentiate between dry- and wet-bulb temperature and tell how each is measured.
– Define the term saturated air.
– Define specific humidity and relative humidity.
– Define enthalpy and explain how it is calculated.
– Demonstrate how to use the psychrometric chart to determine dewpoint temperature, specific humidity, relative humidity, and enthalpy.
Lesson 5 - Tools, Test Instruments, and Safe Work Practices
Pressure gauges; Vacuum-measuring instruments; Leak detection; Thermometers; Hygrometers; Electric test equipment; Recording instruments; Safety
Learning Objectives:– Describe a gauge manifold and tell how it is used.
– Tell what it means to evacuate a refrigeration system and tell how it is done.
– List and describe at least three methods of leak detection.
– Explain the construction of a sling psychrometer and tell how and why it is used.
– Name the instrument used to measure relative humidity.
– Name the instrument used to measure each of the following electrical values: potential difference, current, resistance, and electric power.
– List the four classes of work area hazards, and give an example of each.