Herzing College Skilled Trades
Gas Appliance Repair Training

In this unit, students will discuss the various applications for high-, medium-, and low- temperature refrigeration. Students will describe the basic refrigeration cycle, describe the term ton of refrigeration and explain the relationship between pressure and the boiling point of water or other liquids.

In this unit, students will describe the function of the evaporator or cooling ring, discuss the function of the condensing coil and state the purpose of the metering device. They will describe the proper procedures for working with pressurized systems and vessels, electric energy, heat, cold, rotating machinery, and chemicals; for moving heavy objects; and for utilizing proper ventilation. In addition, they will describe the hand tools used by the refrigerators, air-conditioning, heating, and refrigeration technician and describe the equipment used to install and service air-conditioning, heating, and ventilation systems.

In this unit, students will explain the function of the compressor in a refrigeration system, discuss the compression ratio and describe the four different methods of compression. Students will state the specific conditions under which a compressor is expected to operate; explain the difference between a hermatic compressor and a semi-hermatic compressor; and describe the various working parts of reciprocating and rotary compressors.

In this unit, students will explain the characteristics that make certain materials good conductors, describe how magnetism is used to produce electricity, and state the difference between alternating current and direct current. Students will list the units of measurement for electricity and explain the differences between series and parallel circuits. They will also make general comparisons between different bimetal applications, describe partial liquid, partial vapour-filled controls, and distinguish between the bellows, diaphragm, and Bourdon tube.

In this unit, students will describe ozone depletion and global warming, differentiate between CFCs, HCFCs, HFCs, and HCs, and discuss popular refrigerants and their applications. Discuss refrigerant blends and how temperature glide and fractionation applies to it. Students will discuss refrigerant oils and their applications, define the terms recover, recycle, and reclaim, and describe the methods of recovering refrigerants, including active and passive methods.

In this unit, students will explain three ways in which heat transfers into a structure. They will be able to state two ways in that air is conditioned for cooling. They will be able to describe an air-conditioning evaporator, the three types of air-conditioning compressors, an air-conditioning condenser, an air conditioning metering device, packaged air-conditioning equipment, and split system equipment. Students will be able to list the different types of evaporator coils, and identify the different types of condensers.

In this unit, students will discuss the efficiency and relative operating costs of electric heat, list the types of electric heaters and state their uses and describe how sequencers operate in electric forced-air furnaces. Students will trace the circuity in a diagram of an electric forced-air furnace, perform basic tests in troubleshooting electrical problems in an electric forced-air furnace and lastly, describe typical preventative, maintenance procedures used in electric heating units and systems.

In this unit, students will describe the characteristics of the propeller and centrifugal blowers, take basic air pressure measurements and measure air quantities. Students will list the different types of air-measuring devices, describe the common types of motors and drives and describe various duct systems. In addition, students will describe a return air system and plot airflow conditions on the air friction chart.

In this unit, students will describe the control sequence for an air-conditioning system, explain the function of the 24-V control voltage and explain the operation of the high- and low- pressure controls. They will describe the space thermostat, the compressor contractor and how crankcase heat is applied in some modern equipment. They will identify operating and safety controls and compare modern and older control concepts.

In this unit, students will select the correct instruments for checking an air-conditioning unit with a mechanical problem, calculate the correct operating suction pressures for both standard – and high efficiency air-conditioning equipment under various conditions and calculate the standard operating discharge pressures at various ambient conditions. Students will select the correct instruments to troubleshoot electrical problems in air-conditioning system, check the line- and low-voltage power supplies, and troubleshoot basic electrical problems in an air-conditioning system.

Demonstrate an understanding of workers¿ and others¿ rights and responsibilities under various acts and codes, and be aware of applicable safety organizations.

In this module, students will identify fasteners in term of size, applications, and capacity. They will electrical fasteners, pipe fasteners and general fasteners. Students will determinate the factors used to select each fastener, identify the proper methods for storing and handling of fasteners based on various factors. Identify hand tools in term size and shape, application to specific materials, strength, operating range, assembly and adjustment. They will determine the proper methods for storing and handling hand tools based on set criteria. Students will be able to select the appropriate testing equipment based on its application and method of usage.

In this module, students will identify various properties of gas. Some of these include: specific gravity, density, upper and lower explosive limits, etc. Students will investigate various requirements for combustion and the chemical properties of combustion. The same criteria listed above, will be applied to natural gas as well.

In this unit, students will identify the governing bodies, associations and agencies that regulate the installation of the propane and natural gas, and specify their corresponding responsibilities. Examples of these organizations include: TSSA, MCBS, CSA, CSA International, CGA, ETL, Warnock Hersy, ULC and others.

In this module, students will identify electrical hazards, safe working techniques, procedures and applicable electrical codes. Students will use different electrical measuring and testing instruments to troubleshoot various electrical circuits. Various electrical concepts and theories will be examined. Simple circuits will be examined in detail; constructing diagrams, measuring current and voltage, calculating resistance etc.

In this module, students will refine their customer relations skills. A large focus will be on understanding the customers’ needs coping strategies, active listening, constructive behavior, addressing customer complaints and reconciling differences. A portion of the module is focused on property damage prevention. This includes protective pads, floor mats, safe handling techniques safe and proper clean up.

In this module, students will reference the Natural Gas and Propane installation code and manufactures specifications. They will be exposed to orthographic projections, detailed and assembly drawings, pictorial drawings, schematics and wiring drawings. Students will interpret various charts, listing the advantages and disadvantages of each.

In this module, students will examine various venting systems and the various factors affecting them. They will identify various types of burner design such as inshot, upshot, ported, infrared tube, ceramic and ribbon. Students will view different pilot burner designs and ignition systems. They will explore different sensing methods. In addition, they will describe the requirements to convert an appliance from propane to natural gas or vice versa.

In this module, students examine various steel piping, cooper pipe and tubing, methods of joining, aluminum tubing, identify plastic pipe used in distribution and gas service utilities, identify flexible stainless steel hose and tubing, identify connectors, identify hoses, review code requirements, and explore various connections types, fittings and valves.