Mazda Training manual - part 256

Air Conditioning Fundamentals

TC070-05-01S

 

CONTENTS  

 

page ii

4 –PRINCIPLES OF REFRIGERATION 
Objectives ........................................................................................... 16 
Six Principles ...................................................................................... 16 

Principle One: Heat Transfer ....................................................... 17 
Principle Two: Temperature and Mass ......................................... 18 
Principle Three: Latent Heat of Vaporization................................ 18 
Principle Four: Latent Heat of Condensation ............................... 20 
Principle Five: Pressure and Boiling Point ................................... 21 
Principle Six: Compressed Vapor ................................................ 22 

Review Exercise 3 .............................................................................. 23 

 
 
 

5–AIR CONDITIONING COMPONENTS 
Objectives ........................................................................................... 24 
Overview............................................................................................. 25 
Compressor ........................................................................................ 26 

Axial (Piston-Type) Compressors ................................................ 27 
Vane (Non-Piston-Type) Compressors ........................................ 29 

Condensor .......................................................................................... 31 
Review Exercise 4 .............................................................................. 32 
Receiver / Dryer .................................................................................. 33 
Expansion Valve / Orifice Tube ........................................................... 34 

Expansion Valve .......................................................................... 34 
Orifice Tube ................................................................................. 35 

Evaporator .......................................................................................... 36 
Accumulator........................................................................................ 37 
Review Exercise 5 .............................................................................. 39 

 
 
 

6 – REFRIGERATION CYCLE 
Objectives ........................................................................................... 40 
Stages of the Refrigeration Cycle ....................................................... 40 

Overview...................................................................................... 40 
High Pressure .............................................................................. 42 
Condensation .............................................................................. 43 
Pressure Reduction ..................................................................... 44 
Evaporation ................................................................................. 45 
Orifice Tube System .................................................................... 46 

Review Exercise 6 .............................................................................. 47 

 
 
 
 
 
 

Air Conditioning Fundamentals

TC070-05-01S

 

CONTENTS  

 

page iii

7 – REFRIGERANTS 
Objectives ........................................................................................... 48 
Introduction to Refrigerants................................................................. 48 
CFC-12 (R-12) .................................................................................... 49 

Chemical Structure ...................................................................... 49 
Properties of R-12........................................................................ 49 

HFC134a (R-134a) ............................................................................. 50 

Chemical Structure ...................................................................... 50 
Properties of R-134a.................................................................... 51 

Differences Between Refrigerants ...................................................... 51 
Recycled, Reclaimed, and Extracted Refrigerant ............................... 52 

Recycled Refrigerant ................................................................... 52 
Reclaimed Refigerant .................................................................. 52 
Extracted Refrigerant................................................................... 53 

Storing Recycled Refrigerant .............................................................. 53 
Retrofitting .......................................................................................... 55 

“Drop-In” Replacement Refrigerants for R-12 .............................. 55 
Retrofitting System Components ................................................. 55 

Safety Procedures .............................................................................. 56 
Review Exercise 7 .............................................................................. 57 
 
 
 
8 –AIR CONDITIONING LUBRICANTS 
Objectives ........................................................................................... 58 
Refrigeration Lubrication..................................................................... 58 

Mineral Oil and PAG Oil ............................................................... 58 
Characteristics of Refrigeration Oil .............................................. 58 

Oil Quantity and Component Replacement......................................... 59 
Review Exercise 8 .............................................................................. 60 
 
 
 
9 – AIR DISCHARGE MANAGEMENT 
Objectives ........................................................................................... 62 
Air Flow Management Components.................................................... 63 

Fresh/ Re-circulated Air Door ...................................................... 64 
Blower Fan .................................................................................. 65 
Temperature Blend Door.............................................................. 66 
Defroster Door ............................................................................. 67 
Vent / Face Heater Doors ............................................................ 68 

Review Excercise 9 ............................................................................ 69 

 

Air Conditioning Fundamentals

TC070-05-01S

 

CONTENTS  

 

page iv

10– SERVICING 
Objectives ........................................................................................... 70 
Overview............................................................................................. 70 
Check the Pressure ............................................................................ 71 

Manifold Gauge ........................................................................... 71 
Making the Connection ................................................................ 72 
Using Manifold Gauges ............................................................... 74 
Guidelines.................................................................................... 74 
Evaluating Gauge Readings ........................................................ 74 
Refrigerant Stations ..................................................................... 75 
Recovery ..................................................................................... 76 
Recycling ..................................................................................... 76 
Evacuation ................................................................................... 76 

Review Exercise 10 ............................................................................ 77 
Leak Testing........................................................................................ 78 

Large Leaks ................................................................................. 78 
Small Leaks ................................................................................. 78 
Electronic Leak Detector.............................................................. 79 
Dye Test....................................................................................... 79 
Harder to Spot Leaks ................................................................... 80 
After Detection ............................................................................. 80 

Review Excercise 11........................................................................... 80 
Charging the System .......................................................................... 81 
Review Exercise 12 ............................................................................ 81 
 
 
 
COURSE SUMMARY 
Safety Precautions.............................................................................. 82 
Physical Laws ..................................................................................... 82 
A/C System Components.................................................................... 82 

Compressor ................................................................................. 83 
Condenser ................................................................................... 83 
Receiver / Dryer........................................................................... 83 
Accumulator................................................................................. 83 
Expansion Valve / Orifice Tube .................................................... 83 
Evaporator ................................................................................... 83 

Refrigerants ........................................................................................ 84 
A/C Servicing ...................................................................................... 84 

 

Air Conditioning Fundamentals

TC070-05-01S

 

1 – INTRODUCTION 

 

 

1

 

 
COURSE OVERVIEW 
 
 
Welcome to the Mazda self-study guide, Air Conditioning Fundamentals. Before you begin, 
please read the following information. 

 

 

 

Audience and Purpose 

 

This guide is designed for entry-level automotive technicians. It introduces the basic 
principles of air conditioning (A/C) operation and describes major A/C components. 

 

The guide assumes that you have little or no knowledge about automotive A/C operation. 
Mazda requires the information covered in this guide for more advanced A/C courses.