What HVACR refrigeration-cycle components are explained in this course?

The course covers compressors, discharge and suction lines, condensers, liquid-line filter driers, metering devices, evaporators, receivers, and service valves.

Does the course explain how to use superheat, subcooling, and pressure-temperature charts?

Yes. It explains saturation, PSIG versus PSIA, pressure-temperature charts, superheat, subcooling, and charging diagnostics for fixed orifice and TXV systems.

What HVAC service procedures are covered besides refrigeration theory?

Topics include manifold gauges, refrigerant charging and recovery, vacuum evacuation, nitrogen pressure testing, leak detection, brazing basics, and common system-fault scenarios.

Free Course Image Learn HVAC HVACR Heating Ventalation Air Conditioning

Free online course Learn HVAC HVACR Heating Ventalation Air Conditioning

Duration of the online course: 34 hours and 21 minutes

4.2

(6)

Build job-ready HVACR skills fast with this free online course—learn refrigeration cycles, gauges, superheat/subcooling, and diagnostics for real systems.

In this free course, learn about

Goal-setting and study methods to retain and reinforce HVACR learning
1st & 2nd laws of thermodynamics applied to heat transfer and HVAC behavior
How the refrigeration cycle moves heat: evaporator, compressor, condenser, metering device
Roles of key lines/components: suction, discharge/hot gas, liquid line, filter drier, receiver
Heat concepts: temperature vs heat, BTU, sensible vs latent heat, evaporation vs condensation
Pressure basics: PSIG vs PSIA, atmospheric pressure, boiling point vs pressure relationships
Saturation, PT charts/apps, and how to convert pressure to saturated temperature
Superheat, desuperheat, subcooling: definitions, measurement, and what they indicate
Using manifold gauges, hoses, low-loss fittings, purging/bleeding to avoid contamination
Charging/diagnostics for fixed orifice vs TXV/TEV using target superheat/subcooling
Compressor types and accessories: recip/scroll/rotary, crankcase heaters, switches, mufflers
Refrigerants & oils: blends, glide, CFC/HCFC/HFC phaseouts and basic handling implications
Recovery and evacuation: tanks, machines, methods (push-pull, liquid), vacuum and dehydration
Leak testing and prevention: nitrogen tests, detectors, common evaporator leak causes, brazing flow

About the free online course

Step into the HVACR trade with confidence by learning how heating, ventilation, air conditioning, and refrigeration systems actually move heat. This free online course is designed to turn confusing terms and scattered tips into a clear, practical mental model you can apply on real equipment. You will connect the laws of thermodynamics to everyday service calls, so concepts like temperature vs heat, sensible vs latent load, BTU, pressure, and saturation stop being abstract and start becoming tools for troubleshooting.

You will build a full-picture understanding of the refrigeration cycle and the role each component plays—from the compressor and discharge line to the condenser, metering device, evaporator, and suction line. Along the way, you will learn to interpret pressure and temperature together, use PT charts, and make sense of superheat and subcooling as measurement-based indicators rather than guesswork. This foundation supports better decisions whether you are working on a split system, a package unit, a window AC, a refrigerator, or a cooler.

Because HVAC work is hands-on, the course emphasizes service practices that prevent contamination and reduce mistakes. You will get comfortable with manifold gauge sets, hoses, low-loss fittings, and service valves, and you will understand why small details like valve cores, caps, o-rings, and proper purging matter. The course also connects measurements to outcomes, helping you recognize patterns behind common scenarios such as low airflow, dirty coils, overcharge, undercharge, restrictions, and low ambient conditions.

You will also develop core competence in modern field workflows: charging strategies, recovery and reuse rules, faster recovery approaches, evacuation and dehydration concepts, vacuum measurement, and nitrogen pressure testing for leak checks. In addition, you will strengthen your understanding of refrigerants, blends, glide, and why certain refrigerants have been phased out. Knowledge checks throughout the course reinforce key ideas so you retain what you learn and can apply it on the job. By the end, you will have a strong starting point for entry-level HVACR work and a solid framework for continued professional growth in refrigeration and air conditioning.

Course content

Video class: HVAC 001 Where are you going? Goals or we cant get there 09m
Video class: HVAC 002 making the best of this course, Study, Retain, Reinforce, to reach success! 17m
Exercise: What is a proven learning tool emphasized in the video transcript?

Video class: HVAC 003 1st Law of Thermodynamics 12m
Exercise: According to the first law of thermodynamics, which of the following statements is true?
Video class: HVAC 004 2nd law of thermodynamics simplified for HVAC 09m
Exercise: Which factor does NOT affect the speed of heat transfer according to the second law of thermodynamics?
Video class: HVAC 005 refrigeration intro, Moving heat! basic component. 21m
Exercise: What is the primary function of the compressor in the refrigeration cycle?
Video class: HVAC 005 refrigeration, MOVING HEAT! 10m

Video class: HVAC 006 Compressor, Vapor pump introduction 09m
Exercise: What is the primary function of a compressor in a refrigeration cycle?
Video class: HVAC 007 Discharge line, Hot Gas Line Intro 03m
Exercise: What is the correct definition of the discharge line in an HVACR system?
Video class: HVAC 008 Condensing coil intro 06m
Exercise: What is the primary function of a condensing coil in HVAC systems?
Video class: HVAC 009 Liquid Line and Liquid line filter drier intro 08m
Exercise: What is the primary function of the liquid line filter dryer in a refrigeration system?
Video class: HVAC 010 Metering device, Expansion device introduction 10m
Exercise: What is the primary function of an expansion device in an HVAC system?
Video class: HVAC 011 Evaporator Coil introduction 07m
Exercise: How does an evaporator coil function in a cooling system?
Video class: HVAC 012 Suction, Gas line introduction 03m
Exercise: What does the suction line represent in a refrigeration cycle?
Video class: HVAC 013 Refregeration cycle introduction as one 11m
Exercise: What is the main function of the evaporator in a refrigeration cycle?
Video class: HVAC 014 Moving heat like a sponge 03m
Exercise: What is the primary function of the refrigeration cycle as explained in the passage?

Video class: HVAC 015 Temperature, temperatures 07m
Exercise: What is the relationship between temperature and heat?
Video class: HVAC 016 BTU British Thermal Unit a measure of heat 15m
Exercise: What is the primary unit used to measure heat quantity in HVAC systems?
Video class: HVAC 017 Latent vs Sensible heat 11m
Exercise: How many BTUs are required for water to change from liquid to vapor at 212°F?
Video class: HVAC 018 Evaporator evaporating boiling is a cooling effect 09m
Exercise: What is the effect of evaporation on temperature?
Video class: HVAC 019 Condensing is a heating effect 02m
Exercise: What is the opposite process of evaporation?
Video class: HVAC 020 Adding Evap and Cond to refrigeration cycle 08m

Video class: HVAC 021 Pressure PSIG vs PSIA Atmospherc pressure 10m
Exercise: What does PSIG represent in the context of pressure measurement?
Video class: HVAC 021.1 PSIA example 02m
Video class: HVAC 022 A pressure and boiling water at room temperature. 05m
Video class: HVAC 022 B alcohol Evaporation and boiling 07m
Video class: HVAC 023 Refrigerant introduction 08m
Video class: HVAC 024 Saturation the most important yet misunderstood hvac termanology 09m
Video class: HVAC 025 Temperature Pressure and Saturation connected, NO SET PRESSURES! 04m
Video class: HVAC 026 PSIG to Saturation part 1 the suction pressure and suction saturated on the unit 04m
Exercise: What is the primary purpose of the evaporator coil in an HVAC system?
Video class: HVAC 026 PSIG to Saturation part 2 with the refrigeration cycle 05m
Video class: HVAC 026 PSIG to Saturation part 3 head pressure on the unit 02m
Video class: HVAC 026 PSIG to Saturation part 4 liquid saturation on the ref cycle 02m
Video class: HVAC 027 reading a Pressure Temperature Chart, saturated temperature chart 13m
Video class: HVAC 028 app for temperature and pressure digital PT chart saturated pressure chart 07m
Video class: HVAC 029 Temperature Pressure demonstration 05m

Video class: HVAC 030 Superheat the foundation 13m
Exercise: What is the definition of superheat in the context of HVACR?
Video class: HVAC031 superheat on a unit 02m
Video class: HVAC 032 Desuperheat 04m
Video class: HVAC 033 Subcooling foundation 09m
Video class: HVAC 034 Subcooling on a unit 02m
Video class: HVAC 035 The complete refrigeration cycle 02m
Video class: HVAC 036 Split System refrigeration Cycle 05m
Video class: HVAC 037 A Refrigeration cycle on a refrigerator 03m
Exercise: What is the primary function of the compressor in a refrigeration cycle?
Video class: HVAC 037 B refrigeration cycle on a water cooler 02m
Video class: HVAC 038 package unit refrigeration cycle 06m
Video class: HVAC 039 A Refrigeration cycle window AC 02m
Video class: HVAC 039 B refrigeration cycle with sight glass 02m
Video class: HVAC 039 C refrigeration Cycle visible clear tubing 05m

Video class: HVAC 040 manifold gauge set introduction 23m
Video class: HVAC 041 Hoses and low loss fittings 12m
Exercise: Which of the following statements is true regarding the handling of refrigerant hoses when connecting to a service port on an HVAC unit?
Video class: HVAC 042 A Gauges and hoses on and off the simplest way without contamination. 09m
Video class: HVAC 042B part 2 bleeding across the manifold method without contamination 03m
Video class: HVAC 042C Part 3 Manual low loss valves, applying and removing gauges 02m
Video class: HVAC 042D Part 4 Purging the hoses between different refrigerants 01m
Video class: HVAC 043 replacing a valve core 04m
Video class: HVAC 044 o-rings, caps and locking caps 07m
Video class: HVAC 045 service valve introduction 08m
Exercise: What is the purpose of a service port on an HVAC system?
Video class: PSI, do you know it? pop quiz, bad audio warning 01m
Video class: HVAC 046 Conduction 07m
Video class: HVAC 047 Convection 11m
Video class: HVAC 048 Forced Convection 04m
Video class: HVAC 049 Radiant Heat radiation 08m
Video class: Conduction, Convection, and Radiation [SONG!] 03m

Video class: HVAC 050 introduction to Comfort, the whole house system and motivation to be the best! 09m
Exercise: What is the primary service that professional HVAC technicians should focus on providing to their customers?
Video class: HVAC 051 Introduction to Humidity and dehumidiication 10m
Video class: HVAC 052 Measuring Wet Bulb, Dry Bulb and Humidity 12m

Video class: HVAC 054 Fixed Orfice metering device must match the compressor 03m
Video class: HVAC 055 Superheat will move with a fixed orifice. 10m
Video class: HVAC 056 Target Superheat for a fixed metering device 19m
Video class: HVAC 057 fixed orifice Target Subcooling 06m
Video class: HVAC 058 intro Fixed orfice refregerant charge diagnostics 07m
Exercise: What is likely the issue if an HVAC system has a starved evaporator and a starved condenser?
Video class: HVAC 059 Example fixed metering device with Superheat and Subcooling vs Target SH SC 02m

Video class: HVAC 060 Introduction to the TXV TEV 06m
Video class: HVAC 061 TXV TEV part 2 with Target Subcooling 07m
Video class: HVAC 062 TXV TEV Target superheat vs Superheat, intro level 06m
Video class: How TXV works - Thermostatic expansion valve working principle, HVAC Basics vrv heat pump 08m
Video class: HVAC 063 TXV TEV with superheat and subcooling 08m
Video class: HVAC 064 Superheat and Subcooling vs pressure or line feel 06m
Exercise: What is the proper method for checking the charge in an HVAC refrigeration cycle according to HVAC industry standards?
Video class: HVAC 065 example Superheat and Subcooling with digital gauges 02m
Video class: HVAC 066 Superheat notes 15m
Video class: HVAC 067 Subcooling notes 13m

Video class: HVAC 068 Suction Line a little deeper view 12m
Video class: HVAC 069 suction line accumulator 12m
Video class: HVAC 070 Suction line Filter Drier 14m
Video class: HVAC 071 Receprocating compressor hermetic sealed 12m
Exercise: What is the primary purpose of the discharge line design in a reciprocating compressor?
Video class: HVAC 071 1 bonus Refrigerator Reciprocating Compressor hermetically sealed 03m
Video class: HVAC 072 Semi Hermetic reciprocating compressor intro 01m
Video class: HVAC 072 B Semi hermetic reciprocating compressor opened up 20m
Video class: HVAC 073 Rotary Compressor introduction hermetically sealed 04m
Video class: HVAC 074 A Scroll Compresor introduction hermetic sealed 04m
Video class: HVAC 074 B Scroll compressor cut open 08m
Video class: HVAC 074 C the scroll set only and some unknowns 06m
Exercise: What is the primary function of the scroll within an HVAC compressor?
Video class: HVAC 075 crankcase heater, intro to refrigerant migration 11m
Video class: HVAC 076 Pressure Switch Refrigerant 16m
Video class: HVAC 077 Refrigerant Muffler discharge / hot gas line 02m

Video class: HVAC 078 Air Cooled condensing coils, micro channel, tube and fin, spine fin 13m
Video class: HVAC 079 Water cooled condenser introduction 06m
Video class: HVAC 080 Liquid Line 07m
Video class: HVAC 081 Liquid line filter drier 24m
Exercise: Why is it important to install a liquid line filter dryer close to the metering device inside the house when possible?
Video class: HVAC 082 Liquid line Receiver, King Valve 12m
Video class: HVAC 083 The 3 position service valve 10m
Video class: HVAC 084 sight glass 07m
Video class: HVAC 085 Pump Down 12m
Video class: HVAC 086 A Solenoid Valve part 1 internal workings 11m
Video class: HVAC 086 B solenoid valve part 2 overview and basic applications 04m

Video class: HVAC 087 A. Connections part 1 Brazing, introductory only 16m
Exercise: In HVACR, what is the primary reason for ensuring the brazing rod is pulled in deep into a copper joint?
Video class: HVAC 087 B. Connections part 2 soft solder introduction 06m
Video class: HVAC 087 C. Connections part 3 Flare 08m
Video class: HVAC 087 D connections part 4 Pressed fittings 02m
Video class: HVAC 087 E connections part 5 mechanical fittings pre-charged line sets 06m
Video class: HVAC 087 F Connections part 6 Quick Connect Push To Connect Fittings 10m
Video class: HVAC 088 capillary tubes metering device 04m
Video class: HVAC 089 fixed orifice piston closer look inside 06m
Exercise: What is the purpose of the screen located on the liquid line in an HVAC system?
Video class: HVAC 090 TXV a deeper view of the Thermostatic Expansion Valve TEX TXV 27m
Video class: HVAC 091 EXV EEV Electronic Expansion Valve introduction 08m
Video class: HVAC 092 Automatic Expansion Valve AXV AEV and evaporator pressure should be 23m
Video class: HVAC 093 Flash gas revisited with a deeper view 14m

Video class: Why Does The Evaporator Coil Freeze (And How to Diagnose It) 08m
Video class: HVAC 094 Evaporator a deeper look, comfort cooling, environmental 37m
Video class: HVAC 095 Evap coils for freezers and coolers 08m
Exercise: Why are the fins on an evaporator coil for refrigeration spaced wider apart compared to those on an air conditioning unit?
Video class: HVAC 096 Evaporator coil with fluid instead of air 13m
Video class: HVAC 097 why does an AC freeze 22m
Video class: HVAC 097 B scenario, AC Freezes AFTER servicing 07m
Video class: HVAC 098 ?T Delta T Delta Temperature 17m
Video class: HVAC 099 TD Temperature differential 2 different substances 24m

Video class: HVAC 100 A compression Ratio part 1 29m
Video class: HVAC100 B Compression Ratio part 2 15m
Exercise: What is the importance of the design temperature difference (DTD) in refrigeration systems, particularly for walk-in coolers?
Video class: HVAC 101 Big review Refrigeration cycle with all the details 1h04m

Video class: HVAC 102 Scenario Low Evaporator Airflow effects on the refrigeration cycle 09m
Video class: HVAC 103 Scenario Dirty Condensing coil 05m
Video class: HVAC 104 Scenario: Overcharged system Fixed vs TXV TEV 08m
Video class: HVAC 105 Scenario: Overfeeding Metering device 06m
Video class: HVAC 106 Scenario Restriction and non-condensable 14m
Video class: HVAC 107 Scenario: Low Ambient 11m
Video class: HVAC 108 Scenario Low on charge 16m
Video class: HVAC 109 Example, charging a low system 11m
Video class: HVAC 110 Introduction to Measure quick and wireless probes. 22m
Video class: HVAC 110 part 2 Measure quick and probes, walk in cooler 10m
Video class: HVAC 110 Part 3 Refrigeration Examples, Charging, probes and measure quick 10m

Video class: HVAC 111 Refrigerant CFC 12 and HFC 134A 13m
Video class: HVAC 112 HCFC 22 and HFC 410A 14m
Exercise: What is the primary reason HCFC-22 (R-22) refrigerants are being phased out of use?
Video class: HVAC 112 part 2 oil 01m
Video class: HVAC 113 Disposable refrigerant tanks 09m
Video class: HVAC 114 Refrigerant blends, glide, bubble, dew, zeotrope, azeotrope 28m
Video class: HVAC 115 Mixed refrigerants, factory vs field 16m
Video class: HVAC 116 Charging with Auto low loss fittings on 3 port manifold 15m
Video class: HVAC 117 Charging with Manual Low loss fittings and 3 port manifold 13m
Video class: HVAC 118 Charging with 4 port Manifold manual valve low loss fittings 12m
Exercise: What is the primary benefit of using a four port manifold gauge set over a three port manifold gauge set when working with HVAC systems?
Video class: HVAC 119 Charging with Wireless Probes 12m
Video class: HVAC 120 Heating a tank for low ambient charging 03m
Video class: HVAC 121 Refrigerant weight , volume, temperature, pressure. scales and charging cylindar 08m

Video class: HVAC 123 Recovery Tanks part 1 13m
Video class: HVAC 122 Refrigerant Recovery, why we need to 10m
Video class: HVAC 124 Recovery Tank part 2 do not overfill 13m
Video class: HVAC 124 Reusing refrigerant 10m
Exercise: Under which condition is it legally permissible to recover refrigerant from an HVAC system and reuse it?
Video class: HVAC 125 Recovery Overcharged Unit with gauges 12m
Video class: HVAC 127 Recover empty tank, intro recovery machine 07m
Video class: HVAC 128 Recovery most used but slowest 10m
Video class: HVAC 129 Faster Recovery 15m
Video class: HVAC 130 Next level fast recovery 11m
Video class: HVAC 131 Recovering from a pumped down unit. 10m
Video class: HVAC 132 liquid recovery method high speed 02m
Exercise: What is the main purpose of using the direct liquid method during refrigerant recovery?
Video class: HVAC 133 Push Pull method 03m

Video class: HVAC 134 Vacuum p1 atmospheric pressure revisited 06m
Video class: HVAC 135 Vacuum P2 Atmospheric pressure 04m
Video class: HVAC 136 Vacuum P3 Mechanical vacuum on a barrel 05m
Video class: HVAC 137 Vacuum P4 visualize, measuring vacuum 15m
Video class: HVAC 138 Vacuum P5 dehydration 17m
Video class: HVAC 139 Vacuum P6 Vacuum Pump VS Recovery machine 03m
Exercise: What is the primary purpose of a recovery machine in an HVAC system?
Video class: HVAC 140 Vacuum P7 Vacuum Pump oil 08m
Video class: HVAC 141 Vacuum P8 Changing the vacuum pump oil 08m
Video class: HVAC 142 Vacuum P9 Inside the vacuum pump 08m
Video class: HVAC 144 Vacuum p11 mic pump information 05m
Video class: Brands of Vacuum pumps HVACR 02m
Video class: HVAC 145 Vacuum p12 Removing restrictions for SPEED 09m
Video class: HVAC 146 Vacuum P13 example 1 Fast Vacuum dual 1/2 hoses 32m
Exercise: Which item is NOT recommended to be used when sealing leaking Schrader valve caps?
Video class: HVAC 147 Vacuum p14 Example 2 single hose setup 20m
Video class: HVAC148 Vacuum p15 example 3 The 4 port manifold gauge 15m
Video class: HVAC 149 Vacuum p16 Example 4 Standard manifold 13m
Video class: HVAC 150 Vacuum p17 Example 5 Triple Evacuation 14m
Video class: HVAC 151 Vacuum p18 nitrogen flow with vacuum together 02m
Video class: HVAC 152 Vacuum p19 Review for vacuum 13m
Video class: HVAC 153 Nitrogen Pressure test with Analogue gauges 13m
Exercise: What is the recommended substance to flow through the system while brazing to prevent oxidation buildup?
Video class: HVAC 154 Nitrogen Test temperature compensation, digital gauges 05m
Video class: HVAC 155 Nitrogen test with MQ and Probes 05m
Video class: HVAC 156 Nitrogen test with trace gas 07m

Video class: HVAC 158 low on charge, LEAK! 09m
Video class: HVAC 157 Leak Detectors 07m
Video class: HVAC 159 Why Evaporator coils leak 06m
Video class: HVAC 159 Why evaporator coils leak (Fixed) 10m
Exercise: What is one of the most common causes of evaporator coil leaks in an HVAC system?
Video class: HVAC 160 evaporator coil isolation test 17m
Video class: HVAC161 Condensing unit leak search Tips 13m
Video class: HVAC 162 refrigerant lineset Leaks 09m
Video class: HVAC 163 Leak Dye, stop leak, and additives 10m
Video class: HVAC 164 EPA Study methods and testing tips 15m

Video class: HVAC 165 Evaporative cooling 12m
Video class: HVAC 166 Evaporative cooler how it works inside 19m
Exercise: What is the main reason manufacturers give for not making the pump shaft in swamp coolers out of stainless steel?
Video class: HVAC 167 ICE latent heat of fusion 07m
Video class: HVAC 168 states of water in BTU on a graph. 19m
Video class: HVAC 169 Ice for cooling 06m