HVAC Basics RESIDENTIAL AIR CONDITIONING

Transcription

1 HVAC Basics RESIDENTIAL AIR CONDITIONING Introduction This Instructor s Guide provides information to help you get the most out of Residential Air Conditioning, part of the two-part series HVAC Basics. The contents of the guide will allow you to prepare your students before using the program and to present follow-up activities to reinforce the program s key learning points. Success in the HVAC industry means learning the wide variety of tools, equipment, and materials that experienced repair and maintenance people deal with every day. Featuring crystal-clear live-action demonstrations and easy-to-understand animation, this two-part series provides students with thorough, up-to-date knowledge of HVAC technology. Important safety tips round out the nuts-and-bolts explanations of heating, ventilation, and cooling systems. HVAC Basics correlates to all National CTE Organizational Standards (including the provisions of the Perkins Act). Program Overview Students aiming for a career in air conditioning repair and technology will encounter all the essentials in this program, which summarizes the ins and outs of operation and service. Typical systems for cooling or dehumidifying residential environments are covered. Details on condensing units and their components including the condenser coil, compressor, motor, fan, and accumulator are illustrated along with typical outside housings and insulation materials. The three methods of heat transfer conduction, convection, and radiation are outlined, along with the difference between high side and low side pressure systems. The refrigeration cycle is demonstrated, as are different types of compressors, such as scroll, reciprocating, and piston. Heat pumps, electrical controls, evaporators, and sight glasses are explained. Shopware 2008 Residential Air Conditioning 1

2 Technical Terms Define the following terms. accumulator air conditioning air handler British Thermal Unit (BTU) capillary tube compressor condensing unit condenser coil cooling unit condenser fan conduction control circuits convection cooling system compressor cooling system condenser desiccant evaporator expansion valve heat pump high side pressure system high-low pressure sensor low side pressure system motor fan overload relay piston compressor radiation reciprocating compressor reed valves refrigerant refrigerant lines refrigeration cycle scroll compressor sight glass starter contactor coils step-down transformer thermostat vaporization Discussion Topics 1. Name the two major assemblies of a typical residential air conditioning system. 2. How does an air conditioning system cause a cooling effect inside the residence? 3. What is the purpose of refrigerant oil? 4. Name the parts that are included in the high-side of a cooling system. 5. Describe the function of a cooling system s compressor. 6. List the parts that are included in a residential air conditioning s condensing unit. 7. What can happen if liquid refrigerant enters a cooling system s compressor? 8. Name some of the electrical safety devices used on a residential cooling system to protect an individual and the system itself. Shopware 2008 Residential Air Conditioning 2

3 Short Answer Briefly answer the following questions in your own words: 1. What are the three states of matter? 2. Name three methods of heat transfer. 3. How is the British Thermal Unit applied to the process of refrigeration? 4. Name two types of refrigerants. Shopware 2008 Residential Air Conditioning 3

4 5. Describe the basic procedures used to charge a cooling system. 6. List the two sections of a cooling system. 7. Where is a residential cooling system s condensing unit usually located? 8. Why is a residential cooling system s compressor usually installed on rubber mounts? Shopware 2008 Residential Air Conditioning 4

5 9. List two types of compressors that are used on modern residential cooling systems. 10. Describe the basic operation of a heat pump. Shopware 2008 Residential Air Conditioning 5

6 Assessment Questions Circle the correct answer. 1. Air conditioning is the process that heats, cools, cleans, and circulates air while humidity, or the moisture content, in the. a) raising; accumulator b) controlling; air c) lowering; evaporator d) raising; air 2. The contains the compressor that forces the refrigerant through the cooling system. a) cooling unit b) system evaporator c) condenser coil d) condensing unit 3. When a condenses into a, is released to surrounding objects. a) gas; liquid; heat b) liquid; solid; gas c) gas; solid; heat d) none of these 4. When a vaporizes into a, is absorbed. a) solid; liquid; gas b) gas; liquid; heat c) liquid; gas; heat d) none of these 5. An air conditioner s contains a(n) that collects heat or cools the air in the home. a) cooling unit; evaporator b) condensing unit; accumulator c) evaporator unit; accumulator d) cooling unit; compressor 6. is heat transfer when objects are touching or in contact. a) Convection b) Radiation c) Condensation d) Conduction 7. is heat transfer through the air between two objects. a) Radiation b) Convection c) Conduction d) Vaporization Shopware 2008 Residential Air Conditioning 6

7 8. A is any substance used in a cooling system to absorb during evaporation. a) desiccant; heat b) lubricant; moisture c) refrigerant; heat d) desiccant; contaminants 9. Which of the following components is NOT included in the low-side of a residential cooling system? a) Condenser b) Expansion valve c) Compressor output lines d) All of these 10. A cooling system s pumps the refrigerant as a high pressure, high temperature gas to the. a) accumulator; evaporator b) compressor; condenser c) evaporator; accumulator d) compressor; accumulator 11. The allows to transfer out of the refrigerant and into the outside air surrounding the. a) compressor; moisture; accumulator b) accumulator; heat; evaporator c) condenser; heat; condenser d) condenser; moisture; accumulator 12. The is an air cooled heat exchanger. a) condenser b) evaporator c) accumulator d) receiver 13. A(n) is a precisely sized orifice or opening for regulating or metering refrigerant. a) expansion valve b) capillary tube c) refrigerant sensor d) none of these 14. The is a storage tank in the suction line going to the compressor. a) evaporator b) condenser c) accumulator d) receiver 15. Which of the following is considered the heart of a cooling system? a) condenser b) evaporator c) expansion valve d) none of these Shopware 2008 Residential Air Conditioning 7

8 Assessment Questions Answers 1. b) controlling; air 2. d) condensing unit 3. a) gas; liquid; heat 4. c) liquid; gas; heat 5. a) cooling unit; evaporator 6. d) Conduction 7. b) Convection 8. c) refrigerant; heat 9. d) All of these 10. b) compressor; condenser 11. c) condenser; heat; condenser 12. a) condenser 13. b) capillary tube 14. c) accumulator 15. d) none of these # Shopware 2008 Residential Air Conditioning 8