1. Heating & Climate Control
MG Rover Group
Heating & Climate Control

2. Heating & Climate Control Day One
Introduction And Pre - Course Test.
Air Conditioning Definition.
Air Conditioning Physics.
Air Conditioning System Components.
The Differences In Refrigerants.
The Flow Of Refrigerant In An Air Conditioning System.
Safety Precautions When Handling Air Conditioning Systems.

3. Heating & Climate Control Day Two
Reclaiming, Evacuation And Charging Air Conditioning Systems.
Air Conditioning System Diagnostics And The Equipment Used.
ATC Common Components And The Basic System Operation.
Rover 25 & 45 Systems
Rover 75 HEVAC & ATC
End Of Course And End Test.

4. Standard Heating System
1 Front Face Level Outlet
2 Windscreen and Side Windows Outlet
3 Heater Assembly Casing
4 Air Inlet
5 Blower
6 Heater Matrix
7 Rear Footwell Outlet
8 Front Footwell Outlet
9 Heater Bypass Outlet

5. Rover 25 Standard Heater 1. Blower Unit 2. Heater Duct 3. Heater Unit
4. Blower Switch
5. Face Level Air Flow Control
6. Air Temperature Control
7. Recirculated Air Supply Control
8. Air Distribution Control

6. Rover 25 Heater Circuit

7. What Is Air Conditioning?
Air Circulation
Humidity Control
Air Purification
Temperature Control

8. What Is Humidity ?
The Level Of Water Moisture In The Air Is Partially Dependent On The Temperature Of The Air . So The Feel Of Humidity Will Also Be Dependent On The Temperature.
Measured In %
20Kg of Air at 30*C Can Hold 1Kg of Water If It Holds 900g Humidity is 90%

9. Humidity

10. Disadvantages ! Reduction Of Engine Power Increase Of Fuel Consumption
Environmentally Unfriendly Gas
The Vehicle Costs More To Produce, So The Customer Has To Pay A Premium For It

11. Advantages ! Improved Temperature Control Improved Quality Of Air
Reduction Of Humidity
Some Air Conditioning Systems Automatically Adjust For Different Ambient Conditions

12. How Is Temperature Measured?
Degrees Centigrade ( C )
Degrees Fahrenheit ( F )
Kelvin ( K )
Degrees Rankine ( R )

13. Measurements Of Temperature
C K F R

14. What is Latent Heat?
The Amount of Energy Applied to or Removed From a Substance in Order for It to Change State

15. Four Changes Of State Liquefying Solid - Liquid
Evaporation Liquid - Gas
Condensation Gas - Liquid
Solidification Liquid - Solid

16. Evaporation

17. Energy Used For State Change
0 To 100 C C Liquid To 100 C Gas
418 KJ/KG KJ/KG

18. Factors Which Influence The Rate Of Evaporation
The Type Of Substance.
The Temperature Of The Substance.
The Temperature Of The Substance Surroundings.
The Pressure Acting On The Substance And Surroundings.

19. Measurements Of Pressure
1 Bar ~ 14.7 Psi
1 Bar ~ 100,000 Pascal Or 100 Kpa
1 Bar ~ 1 Kg/cm2
1 Bar ~ 760mm/hg

20. Effects of Pressure on Refrigerant

21. Methods of Heat Transfer
Radiation
Conduction
Convection
Forced Convection

22. Method Of Heat Movement By Radiation
Light Bulbs
Infra Red Heating Lamps
Sun Light
Micro Waves
Radiation

23. Method Of Heat Transfer By Conduction
Oil Circulating Around An Engine.
Coolant To Radiator Fins.
Coolant To Cylinder Block Or Head.
Exhaust Gas To Exhaust Pipe.
Heated Rear Or Front Window.

24. Methods Of Heat Transfer By Convection
Radiator With A Fixed Or Electric Fan
Interior Heating Matrix
Engine Compartment Cooling
The Movement Of The Vehicle Through The Air

25. Components Of An Air Conditioning System
Compressor
Condenser
Receiver Dryer
TXV Valve

26. Components Of An Air Conditioning System
Evaporator
Various Switches
Fans

27. Compressor Types Scroll Type Vane Type Swash Plate Type
Wobble Plate Type

28. Compressor 1 Pulley 2 Clutch connector 3 Inlet connection
4 Outlet connection
5 Control valve vent

29. Sectioned Compressor (swash plate type)
1 Clutch and pulley assembly
2 Shaft
3 Guide pin
4 Outlet port
5 Inlet port
6 Control valve assembly
7 Ball valve
8 Push rod
9 Diaphragm
10 Suction valve
11 Discharge valve
12 Piston
13 Swash plate
14 Lug plate
A = Inlet pressure; B = Outlet pressure; C = Servo pressure;
D = Ambient air pressure

30. Swash Plate Type

31. Compressor (Vane Type)

32. Vane Type Intake Phase

33. Vane Type Compress Phase

34. Vane Type Expel Phase

35. Scroll Type Operation

36. Wobble Plate Type

37. Condenser 1 Modulator 2 Desiccant 3 Filter 4 Plug 5 Heat exchanger
6 Outlet connection
7 Inlet connection
8 End tank

38. Receiver Dryer

39. Five Functions Of A Receiver Dryer
Reservoir For The Refrigerant
Remove Gas Bubbles
Remove Moisture And Acids
Filter Out Particulate
Location For Sight Glass

40. Sight Glass Diagnosis Clear System OK or Empty Foamy
Refrigerant Low or Contaminated With Air
Streaky
Refrigerant Low
Cloudy
Receiver/Dryer Broken & Contaminated System

41. TXV Valve Outlet Inlet Diaphragm Chamber Diaphragm
Equaliser Circuit (Internal Type)
Pressure Spring
Capillary Tube
Valve
Equaliser
Sensing Tube

42. Block Type TXV 1 Diaphragm 2 Housing 3 Metering Valve
4 Inlet Passage to Evaporator
5 Outlet Passage From Evaporator
6 Temperature Sensitive Tube

43. Evaporator

44. Evaporator Temperature Sensor

45. Refrigerant Flow 1.Compressor 2.Condenser
3.Receiver Drier –Integral To the Condenser on Rover 75
4.Thermostatic Expansion Valve
5.Evaporator
6.Flow Into Compressor
7.Blower Motor
8.Cooling Fan
9.Cooling Air Flow

46. Rover 75 System With Sub Cooler
1.Compressor
2.Condenser
3.Receiver Drier –Integral To the Condenser on Rover 75
4.Thermostatic Expansion Valve
5.Evaporator

47. Advantages of a Sub Cooler
Improved System Performance
Cost Reduction
Weight Reduction
Reduction in Power Consumption
Reduction in Refrigerant Charge Quantity (Cost Saving)
Less Joints in the System (Better Reliability – Less Chance of Leakage)

48. Trinary Switch

49. Typical Trinary Switch Working Pressures
Stage 1 = Below 2 Bar - Switches Off
2.3 Bar Reinstates
Stage 2 = 19 Bar Increase Fan Speed
Stage 3 = Above 27 Bar - Switches Off
21 Bar Reinstates

50. System Safety Cut-outs
Engine RPM Too Low – ECM
Engine RPM Too High – ECM
System Pressure Too Low – Trinary Switch
System Pressure Too High – Trinary Switch
Pressure Relief Valve

51. Air Conditioned System
1 Front Face Level Outlet
2 Windscreen and Side Windows Outlet
3 Heater Assembly Casing
4 Air Inlet
5 Blower
6 Evaporator
7 Heater Matrix
8 Rear Footwells Outlet
9 Rear Face Level Outlet
10 Front Footwells Outlet
11 Heater Bypass Outlet

52. Properties Of Refrigerant
Have A Fast Change Of State
Is Not Explosive Or Flammable
Is Not Poisonous To Humans
Long Shelf Life
Is Not Corrosive To System Components

53. Dichlorodifluoromethane
Refrigerant Type R12
R12
Dichlorodifluoromethane
Chroloroflorocarbon
Chlorine
Fluorine Boiling Point C
Carbon

54. Refrigerant Type R 134a R 134a Tetrafluoroethane Hydroflurocarbon
Hydrogen
Fluorine Boiling Point –26.5C
Carbon

55. Ozone Protection June 1974 University Of California
March 1985 United Nations Environmental Plan ( U N E P )
1987 Montreal Protocol
Identified Five Kinds Of Freon That Were Subject To Regulations
Freon 11, 12, 113, 114, 115
1989 Vienna Treaty
Total Abolition By 2000

56. Good Working Practices
Protective Sealing Plugs Must Remain In Position, Assembly.
If Caps Are Removed Or Damaged It Should Not Be Fitted And Returned.
Always Use A Backing Spanner.
Discard Opened Containers Of Oil After 1 Month.
All Fixings Should Be Tightened To Their Correct Torque Settings.

57. Good Working Practices
If the System Is Found Empty or Open the Receiver Dryer Must Be Replaced
If There Is No Expulsion of Gas When Sealing Caps Are Removed the Compressor Must Be Replaced
New ‘O’ Rings Must Be Fitted Upon Assembly
New Components Must Be Allowed to Reach Room Temperature Before Fitment

58. Safety Precautions ! Wear Full Safety Goggles Wear Safety Gloves
Know Where The First Aid Kit Is Located
No Smoking

59. Recovery Procedure
Reclaim
Evacuate
Recharge
Test

60. Testing The System The Engine Rpm At Approx. 1500rpm
The AC Inlet Temperature Of At Least C
The Heater Unit Settings, Set To Maximum Cooling And Fan Speed Also At Maximum, Doors Open.

61. Normal System
Low Side
1.5 to 2.5 bar
High Side
10 to 15 bar

62. Poor Efficiency Low Side 0.5 To 1.5 Bar High Side 6.0 to 8.0 Bar
Suspect :-
Under-charged(if Pipes Appear Frosted – Suspect Blocked or Clogged System)

63. Erratic Readings Low side 0.5 to 2.5 erratic High side
7.0 to 15 bar erratic
Suspect :-
Moisture in system

64. Intermittent Operation
Low side
2.0 to 3.0 bar
High side
20.0 to 25.0 bar
Suspect :-
Overcharged system

65. Poor Efficiency Low side 4.0 to 6.0 bar High side 8.0 to 10.0 bar
Suspect :-
Faulty compressor

66. Pipe Frosting Low side 2.0 to 3.0 bar High side 20.0 to 22.0 bar
Suspect :-
Sticking TXV valve

67. Rover 25 System Layout 1. Evaporator 2. Thermostatic Expansion Valve
3. High Pressure Servicing Connection
4. Receiver/drier
5. Condenser
6. Compressor
7. Low Pressure Servicing Connection

68. Rover 45 K Series Layout 1. Compressor
2. Low pressure servicing connection
3. Evaporator
4. Thermostatic expansion valve
5. High pressure servicing connection
6. Receiver/drier
7. Condenser

69. Rover 45 Diesel System Layout
1. Compressor
2. Low pressure servicing connection
3. Evaporator
4. Thermostatic expansion valve
5. High pressure servicing connection
6. Receiver/drier
7. Condenser

70. Rover 45 KV6 Layout 1. Compressor 2. Low pressure servicing connection
3. Evaporator
4. Thermostatic expansion valve
5. High pressure servicing connection
6. Receiver/drier
7. Condenser

71. Rover 75 Layout 1 Low pressure servicing connection
2 High pressure servicing connection
3 Refrigerant lines
4 Evaporator and thermostatic expansion valve
5 Condenser
6 Compressor

72. ATC System Inputs External Temperature Sensor
Heater Coolant Temp Sensor
Interior Temperature Sensor
Evaporator Temp Sensor

73. ATC System Inputs Sunlight Sensor Feedback Potentiometer
Driver Control Switches
K-Bus

74. ATC Component Layout 1 In-car temperature sensor 2 ATC ECU
3 Heater coolant temperature sensor
4 Power transistor
5 Evaporator temperature sensor
6 Sunlight sensor
7 Trinary pressure switch

75. ATC System Outputs Heater Blower Fan Control Air Conditioning Request
Blend Motors

76. ATC System Outputs
Directional Motors
Display Functions
K-Bus

77. ATC Control Diagram 1 Heater coolant temperature sensor
2 Sunlight sensor
3 RH temperature servo motor
4 Distribution servo motor
5 ABS modulator
6 LH temperature servo motor
7 Instrument pack
8 Fresh/Recirculated air servo motor
9 BCU
10 Power transistor
11 Blower
12 Blower relay
13 In-car temperature sensor
14 ATC ECU

78. Heater Blower Control 31 Speeds in Automatic Mode
6 Speeds in Manual Mode ( 3,8,14,19,25 & 31)
Blower Disabled in Auto Mode If Below -15ºC
Blower Limited to Speed 3 in Auto Mode If Between -15ºC & 20ºC

79. Heater Blower Control
When Cooling, Blower Purges Ducts for 5 Seconds at Speed 3 When Switched on – Progressing to Full Speed Within 6 Seconds
On Reaching Selected Temperature Blower Reduces & Stabilises at 5 Steps
Solar Heating Correction Raises Blower Speed by 6 Steps When Face Vents Selected

80. Heater Blower Correction
Blower Speed Reduced by 8 Steps Between 25 & 60 Mph
Blower Speed Increased by 8 Steps Between 60 & 25 Mph

81. Heated Rear Window Operation
Ambient Air Temperature Below 10ºC – Engine Started – Auto on for 20 Mins
Manually Switched on – Below 10ºc – on for 20 Mins
Manually Switched on – Above 10ºc – on for 12 Mins

82. ATC Switch Pack & ECU

83. ATC ECU Self Diagnosis Carried Out Every Ignition Cycle
Audible Bleep 3 Times (sunlight sensors disabled)
Auto Window on Display Flashes for 20 Secs
Reverts to Default Settings

84. Default Values Temperature Scale Set to Market Preference
Outlet Temperatures Set to 22ºC
Audible Warning Switched on

85. ATC ECU Manual Diagnosis
Press & Hold Auto & Air Distribution Buttons
Switch on Ignition
Audible Warning
Entire LCD Display Lights up
Window Displays FC & Number

86. ATC Self Test Fault Codes

87. Fuel Burning Heater

88. Fuel Burning Heater 1.Combustion Air Fan 2.Electronic Board
3.Heat Exchanger
4.Stainless Steel Burner
5.Fuel Supply
6.Glowpin/flame Detector
7.Evaporator
8.Water Pump

89. Benefits of Fuel Burning Heater
·     Requires a Very Small Electrical Supply As Heat Is
Generated by Burning Fuel and Therefore It Doesn’t
Drain the Battery
·     Produces a High Power Heating Output of 5 KW
·     Good Thermal Efficiency
·    Environmentally Friendly Because of Optimum and
Continuous Combustion