HVAC Technology II

Course Duration: Full Year

Category: Career & Technical Education, Electives, High School

Prerequisite: HVAC-R I

Assessment: Pre-Test, Lesson Practice, Unit Exams, Mid-Term Exam, Final Exam

Language: English

Course Overview

This Heating-Ventilation-Air Conditioning-and Refrigeration course builds on the knowledge and skills taught in HVAC Technology I to provide students the preparation they need for their career and for the HVAC-R certification exam. Acellus HVAC-R II is A-G Approved through the University of California.

This course was developed by the International Academy of Science. Learn More

Scope and Sequence

Unit 1: Alternating CurrentIn the introductory unit of this course, students are introduced to alternating current generation, sine wave generation, direct current generation, frequency, single phase power, three phase power, resistive circuits, and inductive circuits. This unit will also introduce how a transformer operates, different types of transformers, transformer phasing, correct transforming, single phase motors, multi-speed motors, capacitors, split phase motors, permanent split capacitor motors, CSCR and CSIR motors, and how to test a shaded pole motor, as well as learning about three phase motors, motors of grounded windings, fuses, and how to test capacitors.Unit 2: CompressorIn this unit students explore the use of a hermetic compressor and a semi-hermetic compressor, how a reciprocating compressor operates, the operation of a rotary compressor, a scroll compressor, a screw compressor, and a centrifugal compressor, and capacity control and different controls of differing compressors. In this unit students will also learn the multiple compressor method, the cylinder unloading method, a scroll compressor capacity control, hot gas bypass capacity control, screw compressor control methods, and the centrifugal compressor capacity control method.Unit 3: Compressor FailuresWithin this unit students will learn about compressor slugging, flood back system contamination, compressor overheating, common compressor electrical failures, the operating voltages for compressors, and three-phase voltage imbalance, as well as compressor motor overload protection, current and voltage monitoring devices, and pressure protection devices. Students will also learn about compressor oil protection, lock out protection, short cycle protection, and electronic head pressure control.Unit 4: Compressor AnalysisIn this unit, students learn about mechanical evaluation of a hermetic compressor, and how to perform an operating analysis. Additionally, students will learn to operate a compressor as well as how to perform an electrical check.Unit 5: HVAC-R Refrigerants and OilsThis unit guides students through the history of refrigerants and oils, refrigerant characteristics, common refrigerants and their applications, and refrigerant structure. This unit will also guide students through CFC refrigerants, HCFC refrigerants, HFC refrigerants, HC refrigerants, refrigerant identification, environmental effects of refrigerants, ODP and GWP, and EPA certification, as well as refrigerant composition, the three types of blended refrigerants, bubble point, dew point, and temperature glide. Students will then learn about fractionation, refrigerant safety classifications, cylinder identification, refrigerant cylinder safety, the temperature pressure chart, the lubricating oil properties, the different oil types, the oil handling guidelines, refrigerant conversion issues, and common refrigerant conversions.Unit 6: System Evacuation, Recovery, Charging and Leak DetectionThis unit introduces students to leak detection, leak detection methods, how to leak test a system, refrigerant recovery, refrigerant recycling, refrigerant reclamation, refrigerant record keeping, and how the EPA is enforcing the law. This unit will also be discussing types of refrigerant recovery equipment, recovery safety, evacuation principles, evacuation procedures and equipment, and how to charge by the super heat method.Unit 7: Metering DevicesStudents begin this unit learning about the functionality of metering devices, direct expansion systems, fixed orifice metering devices, the expansion of valve metering devices, the distributor, capillary tube devices, and how to troubleshoot a fixed metering device. Students will also learn about manual versus automatic expansion valves, thermal expansion valves, internal versus external equalized expansion valves, how to troubleshoot an expansion valve issue, and how to locate an expansion valve sensing bulb.Unit 8: Heat PumpsIn this unit students will learn about heat pumps, coefficient performance, the heat pump refrigeration cycle, air-to-air heat pumps, water-to-air heat pumps, water-to-water heat pumps, air-to-water heat pumps, and ground source heat pumps. Students will also learn about reversing valves, accumulators in heat pumps, dual fuel heat pump systems, electric heating, and how to troubleshoot electric heating.Unit 9: Basic MaintenanceWithin this unit students will gain knowledge of gaskets, packing, seals, and bearings, non-mechanical versus mechanical seals, different bearing types, properties of lubricants, different belt types, belt drive maintenance, and environmental health hazards. Students will also learn about gas furnace maintenance, how to inspect a heat exchanger, maintenance procedures for cooling equipment, and maintenance for electronic air cleaners.Unit 10: Chimneys, Flus, and VentsIn this unit students discuss combustion and flu gas properties, the basic requirements for venting, how to properly size a furnace and a heat anticipator, and the general guidelines for metal vents. They also explore natural-draft versus induced-draft furnaces, and how to properly size metal venting, as well as condensing a furnace venting practices.Unit 11: Sheet Metal Duct SystemsStudents will gain understanding of the common type of sheet metal used in ducts, duct sealing, how to properly support and hang metal duct, access doors and take offs, and flexible duct information. Students will also learn about the use of fiberglass duct, as well as duct systems overall.Unit 12: Commercial SystemsIn this unit, students will learn about operating characteristics of commercial systems, single zone constant volume systems, and multi-zone constant volume systems. In addition, they will investigate variable volume temperature systems, standard diffusers versus concentric diffusers, commercial packaged equipment types, and economizers.Unit 13: Indoor Air QualityThis unit teaches students about factors that affect air quality, humidity control, humidifiers versus dehumidifiers, mechanical air filters, electronic air cleaners, and ultraviolet light air purification systems. Students also learn about AC/Energy/Heat recovery ventilation systems.Unit 14: Introduction to Hydronic SystemsIn this concluding unit students will learn about hydronic heat system principles, hydronic heating types, hydronic heating operation and safety controls, and the expansion tank. Students will finish up with learning about single-pipe versus two-pipe systems and hydronic heat zoning.