Heating, Cooling and Air Conditioning Level 1

1. Heating, Cooling andAir ConditioningLevel 1

2. This course and many others are available on the BFRC E-Learning web site Visit http://education.bfrco.com You will need your UID number and password to log in

3. E-Learning • Once you complete the On-Line course you will be able to print a certificate of achievement.

5. In this "Certified For Excellence" module you will learn how to • Explain the principals of air conditioning • Describe the four cycles of refrigeration • Describe the high and low pressure sides of an air conditioning system • Explain the basic function and construction of each major part of a typical heating and air conditioning system • Summarize the operation and interaction of heating, ventilation, and air conditioning systems • Describe safety precautions to be observed when working on heating and a/c systems

11. LAWS AND REGULATIONS

16. PERFORMING A/C SERVICES Before servicing or repairing an A/C system, you must understand and follow these rules and procedures: • Anyone performing A/C service or repair must be certified. (see Certification section in your workbook) • Only EPA approved recover or recover/recycle equipment may be used. (see equipment section in your workbook) • A visual and electronic leak detection test must be performed before any repair or service is performed. • Refrigerant may be added for testing. • Technicians are required to recover the refrigerant during the repair or service of any A/C system. • Any A/C system found to have a leak must be identified to the customer. The customer, however, is not obligated to have the leak repaired and has the option to just have the system repaired. This rule does not apply in Wisconsin, the city of Austin, TX., the Bay Area Air Quality Management District in Northern California and the South Coast Air Quality Management District in Southern California.

18. BFRC PERFORMS FOUR BASIC TYPES OF A/C SERVICE

19. IMACA TESTING

21. PRINCIPALS OF REFRIGERATION

22. An automotive air conditioning system uses a refrigerant system, a heating system and a ventilation system to provide a comfortable environment in all weather conditions. Although the refrigerant system is commonly referred to as the air conditioner, all three systems are different components that work together to provide "Conditioned Air"

23. The purpose of an A/C system is customer comfort • This system controls the temperature and removes moisture, dust and pollen particles from the passenger compartment • By removing moisture from the air, the relative humidity is lowered and customer comfort can be achieved at higher temperatures

24. What is Cooling? • The term cooling may be defined as a process of removing heat from an object. • Actually there is no such thing as cooling. We are saying that an object is not as hot as something else • The normal use of the word cold is generally determined by a comparison to the human sense of comfort. • Cold and Hot are actually different degrees of heat.

27. Transfer of heatIn order to cool or heat something we must transfer heat from one place to another The transfer of heat can be accomplished in three ways • Conduction • Convection • Radiation

28. Conduction Example?

29. Convection Example?

30. Radiation Example?

31. Heat Transfer • Heat always flows from a hot area to a cold area • The rate of heat transfer is dependent on the temperature differential. The greater the differential, the faster heat will flow. • Heat transfer continues until both temperatures are equal.

34. Three states of matter • Solid • Liquid • Vapor

35. Heat is the controlling factor

36. At room temperature hydrogen and oxygen (H2O) molecules, when combined, are fluid and form a liquid (water). • When water is hot enough, its molecules move fast enough to separate, forming a vapor. • When enough heat is removed from water the molecules move slowly enough to form a solid, (ice).

37. BTUBritish Thermal Unit • Heat is a basic form of energy that, among other things it causes substances to rise in temperature. • Heat is measured in British Thermal Units (BTUs). • One BTU is the amount of heat required to raise the temperature of one pound of water 1 degree F at sea level • All substances above -459 degrees F (absolute zero) contain some heat.

38. LATENT HEAT As a liquid evaporates heat is absorbed buy that liquid As a vapor condenses heat is released from that vapor

39. LATENT HEAT OF EVAPORATION

40. LATENT HEAT OF CONDENSATION

41. Pressure

42. Pressure and Temperature Relationships • Increasing the pressure acting on a liquid increases the boiling point of the liquid allowing the liquid to absorb more latent heat.

43. Lowering the pressure acting on a liquid lowers the boiling point of the liquid allowing that liquid to release more latent heat

44. STANDARD DAY According to the U.S. National Oceanic and Atmospheric Association, (NOAA), the standard day is 29.92 in Hg (14.7 lbs.) of pressure at sea level and 59 degrees Fahrenheit of temperature. At these conditions water boils at 212 degrees Fahrenheit. If water were boiled at an altitude of 15,000 feet, it would boil at approximately 165 degrees. WHY?

45. Pressure / Temperature Relationship as applied to Liquids We must understand how varying temperature and pressure affect liquids. The fact that pressure changes can affect the vaporization (boiling point) and condensation point of a substance is called the pressure / temperature relationship. The refrigeration process makes use of this vaporization and condensation effect.

46. If the pressure acting on a liquid were increased, what would happen to the boiling point of the liquid? WHY?

47. WIND SQEEZERS • Pressure also affects the temperature of gasses and vapors • Compressing a gas or vapor increases its temperature without adding extra heat This is why air compressors get so hot

48. An A/C compressor uses pressure to concentrate the heat of a vapor

49. A heat transfer occurs when the vapor contacts a cooler surface, which condenses it into a liquid Lowering the pressure of this liquid causes it to boil and absorb heat as it changes state

50. TYPES OF REFRIGERANT The liquids used in the refrigeration system which provide the actual cooling effect are referred to as "REFRIGERANT" • There are two types of refrigerant used in automotive air conditioning systems. R-12 & R-134a