Mazda Training manual - part 266

Air Conditioning Fundamentals

TC070-05-01S

5 – AIR CONDITIONING   
COMPONENTS 

 

38

Figure 21 shows how an accumulator operates. The accumulator tank 
separates liquid refrigerant from gaseous refrigerant. Desiccant in the 
accumulator tank removes moisture from the refrigerant before it is sent 
on to the compressor. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

FIGURE 21. The 
accumulator tank 
prevents liquid 
refrigerant from 
entering the 
compressor, where it 
could damage the 
A/C system.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

From evaporator

 

ACCUMULATOR TANK

To A/C compressor

Gaseous Refrigerant With Liquid

Liquid Refrigerant

Gaseous Refrigerant

Air Conditioning Fundamentals

TC070-05-01S

5 – AIR CONDITIONING   
COMPONENTS 

 

39

REVIEW EXERCISE 5 
 
Match each component on the left to one of the descriptions on the right. Check your 
answers with the answer key on page 42. 

 

1.   Receiver/Dryer  

_____  

A.   Transfers heat from passenger compartment 

to refrigerant 

 
2.   Compressor  

_____  

B.   Lowers pressure by restricting refrigerant flow 

through a fixed opening 

 
 
3.   Expansion valve  

_____  

C   Transfers heat from refrigerant to outside air 

 
4.   Evaporator  

_____  

D.   Removes moisture from refrigerant 

 
5.   Orifice tube  

_____  

E.   Lowers pressure by restricting refrigerant flow 

through a pintle valve 

 
6.   Condenser  

_____  

F.   Raises pressure of refrigerant 

 

Air Conditioning Fundamentals

TC070-05-01S

6  – REFRIGERATION 
CYCLE 

 

40

OBJECTIVES 
 
 
After completing this section, you will be able to: 
 
• 

Describe the changes that take place in refrigerant as it flows through the A/C system. 

 
• 

Explain the role that each major A/C component plays in the refrigeration cycle. 

 
 
 
STAGES OF THE REFRIGERATION CYCLE 
 
 
 
Overview 
 
The previous section of this Guide showed that an automotive A/C system is a set of 
components that circulate refrigerant through a closed circuit. Refrigerants are special 
chemicals designed to absorb and release heat quickly. They have a very low boiling point 
— well below 0° F (-18° C) at sea level — and they respond predictably to changes in 
pressure. (The next section of this Guide describes refrigerants in more detail.) 
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Air Conditioning Fundamentals

TC070-05-01S

6  – REFRIGERATION 
CYCLE 

 

41

 

 

 

FIGURE 22 The 

refrigeration cycle 

includes a 

high-pressure side 

(top) and a 

low-pressure side 

(bottom). In addition, 

the refrigerant 

changes from a 

vapor (left) to a 

liquid (right).

 

 

Compressor

 

Condenser

 

Receiver/ dryer

 

Expansion valve

 

Evaporator

 

 

Answers to Review 
Exercise 5

 

1. D 

2.  F 

3.  E 

4.  A 

5.  B 

6. C 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 22 shows how refrigerant circulates through an A/C system. As it 
flows through a complete cycle, the refrigerant undergoes two changes 
in pressure and two changes of state. The four sections of the 
illustration show the changes. 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
The horizontal line divides the cycle into a “high-pressure side” on top 
and a “low-pressure side” on the bottom. The high-pressure side starts 
at the compressor outlet, extends through the condenser and 
receiver/dryer, and ends at the expansion valve. 

 

When refrigerant leaves the expansion valve, its pressure drops and it 
enters the low-pressure side. The low-pressure side extends through 
the evaporator and into the compressor’s inlet. 

 

The vertical line in the illustration marks the points where the refrigerant 
changes state. On the left side of the circuit, the refrigerant is a vapor; 
on the right side, it is a liquid. 

 

 

 

 

 

HEAT

HEAT