1. Fundamentals of HVAC PPT a7 m01 Final
Welcome to HVAC
Fundamentals of HVAC PPT a7 m01 Final
Copyright 2002 General Motors Corporation

2. The material contained in this course component was accurate and current at the time of course development.

3. Objective Describe the theory and operation of: HVAC Systems
Cooling Systems
Air Distribution Systems
Principles of Refrigeration
Air Conditioning and Comfort
Properties of Heat and Temperature

4. Objectives Describe the theory and operation of:
Vaporization and Condensation
Basic Refrigeration cycle
Factor Affecting Heat Transfer

5. HVAC Heating Ventilation Air Conditioning
The introduction of this class is heating ventilation and air-conditioning

6. HVAC Sub Systems
Cooling
Refrigeration
Air Distribution

7. Refrigeration System R-12 R-134A CCOT VDOT CCTXV VDTXV
Types of Refrigerant
R-12
R-134A
CCOT stands for cycling clutch orifice tube
VDOT stands for variable displacement orifice tube
CCTXV stands for cycling clutch expansion valve
VDTXV stands for variable displacement expansion valve
The types of refrigerant is R 12 and R134A

8. CCOT Condenser Accumulator-Dryer Evaporator Muffler
Pressure Cycling Switch
Thermostatic Switch
Pressure Cut-off Switch
Pressure Sensor
In a CCOT system the clutch cycles to maintain pressure and refrigerant flow based on the demand of the evaporator In A CCOT system we have as parts a condenser in a cumulate or dryer and evaporator bubble for a pressure cycling switch a thermostatic switch a pressure cutoff switch and a pressure cents
The condenser converts a high pressure gas into a high-pressure liquid by releasing heat to the outside air
The accumulator dryer is a storage device and it also dries the refrigerant in the system
Evaporator takes heat from the passenger compartment and the heat to the refrigerant to the refrigerant the refrigerant turns to gas mingles to the accumulator dryer in the accumulator dryer it is a liquid separator and a refrigerant reservoir and a refrigerant or drier
the pressure cycling switch maintains the pressure of the system by cycling the clutch off and on
The pressure cut off switch maintains a maximum pressure in the system

9. VDOT Condenser Accumulator-Dryer Evaporator Muffler
Pressure Cut-Off Switch
Pressure Sensor
A VDOT is a variable displacement orifice tube it has a condenser accumulator dryer an evaporator a muffler a pressure cut off switch and a pressure sensor.
The high-pressure gas comes from the compressor to the condenser where he is released to the atmosphere and the refrigerant turns from a gas to liquid it goes to and orifice to tube where it changes from a high-pressure liquid to a low-pressure liquid in the evaporator it takes on heat from the passenger compartment and changes from a low-pressure liquid to a low-pressure gas from there goes to the accumulator dryer the accumulator dryer is a storage device it separates gas and vapor and it’s a dryer for the refrigerant from there goes to the compressor which changes a low-pressure gas to a high-pressure gas

10. CCTXV Condenser Receiver-Dryer Evaporator Muffler Thermostatic Switch
Pressure Cut-Off Switch
Pressure Sensor
CCTXV has a condenser or receiver dryer and evaporator a muffler a thermostatic switch a pressure cut off switch and a pressure sensor.
From the compressor a high-pressure gas goes to the condenser and changes to a high-pressure liquid by releasing heat to the atmosphere from there goes it goes to receiver dryer to receiver dryer is a storage device also a desiccant to keep the refrigerant dry from Blair it goes to a thermostatic expansion valve which reduces the high-pressure liquid to a low-pressure liquid at the evaporator the low-pressure liquid takes on he from the passenger compartment and transforms to a low-pressure gas from there we go to the compressor which changes the low-pressure gas to a high-pressure gas

11. VDTXV Condenser Receiver-Dryer Evaporator Muffler
Pressure Cut-Off Switch
Pressure Sensor

12. Rear Units
Thermostatic Expansion Valve
Evaporator
Refrigerant Lines

13. Cooling Systems
Air Intake
Condenser
Radiator
Fans
Seals and Shroud

14. Air Distribution System
Blower
Evaporator
Heater
Air Doors
Air Ducts
Control System

15. Principles of Refrigeration
Behaviors of Heat
Properties of Heat
Behavior of Refrigerants
Effects of heat and pressure on liquids and gases

16. Air Conditioning and Comfort
Moisture
Heat
Pollen
Dust
Air-conditioning systems are systems that remove moisture heat to Pollen and Dust from the air to give us a comfortable environment

17. Heat versus Temperature
Heat is measured in BTUs
Heat is the energy in a substance
Temperature is measured in degrees
Temperature is the intensity level
Heat is measured in BTU heat is the energy in a substance it is a volume of heat or volume of energy in a substance for instance a cup of coffee at 71 degrees Fahrenheit has 100 BTU of heat a coffeepot at 71 degrees Fahrenheit would have 1000 BTU of heat temperature is the measure of intensity of heat it is measured in degrees

18. Heat Transfer
Heat always transfers from hot to cold

19. Changes in state of matter
All matter has three states, solids which have a little atomic activity, liquids which have more atomic activity than a solid and a gas which has the most atomic activity.

20. Heat of Vaporization
A specific amount of heat is needed to change a liquid to a vapor
Known as latent heat
Latent heat of water 970 BTU/lb
Latent of 134A BTU/lb
The heat of vaporization is the specific amount heat that is needed to change a liquid to a vapor. It is also known as latent heat or hidden heat. The latent seat of water is 970 BTU/lb. Late in heat of 134A is 93 BTU/lb.

21. Vaporization and Condensation
Vaporization is is the addition of latent heat to a liquid
Condensation is the removal of latent heat from a liquid.
Vaporization is is the addition of latent heat to a liquid. Condensation is the removal of latent heat from a liquid.

22. Pressure Temperature
The pressure acting on a liquid is increased, the boiling point of the liquid increases
Lowering the pressure acting on a liquid lowers its boiling point
The increased pressure on a liquid increases the boiling point of the liquid. Lowering the pressure on a liquid lowers the boiling point of the liquid.

23. Effects of pressure on gases and vapors
Low pressure low temperature
High pressure high temperature
Pressure on a vapor. As you increase the pressure on a vapor the temperature rises. As you decrease the pressure on vapor that temperature reduces.

24. Basic Refrigeration cycle
The basic refrigerant cycle is adding heat to a liquid creates a vapor, compressing a vapor changes it to a high pressure vapor, taking heat away from a vapor changes it to a liquid.

25. Controlling refrigerant flow

26. Factor Affecting Heat Transfer
Coolant Fan
Condenser
Blower Motor
Humidity
Sun Load

27. Summary

28. Thank you for attending
Fundamentals of HVAC
Copyright 2002 General Motors Corporation