operation. The types are reciprocating, rotary, and
Q11-9. What term is used to identify the process by
centrifugal (fig. 11-2).
which a vapor changes state to a liquid when
heat is removed from the vapor?
The function of the compressor is the same for all
three types, but the mechanical means used to
accomplish this function differ considerably. The only
type discussed in this manual is the reciprocating
compressor, which is the type used in mobile
air-conditioners. You are required to troubleshoot and
Q11-10. Which of the following is one inherent
maintain these units.
disadvantage that is shared by both R-12 and
Reciprocating compressors used in
air conditioning and refrigeration are designated as
1. They both evaporate at very low tem-
open, semi-hermetic, or hermetic. The open com-
2. They are both very unstable compounds
3. The both have the capacity to absorb heat
4. The both have the capacity to absorb
Q11-11. Which of the following is NOT a major
component of an air-conditioning system?
A liquid exchanger
An expansion valve
COMPONENTS OF AN
LEARNING OBJECTIVES: Identify the
components of air-conditioners. Recognize the
working relationships among air-conditioning
An air-conditioning system consists of six basic
components--the compressor, the condenser, the liquid
receiver, the heat exchanger, the metering device, and
air-conditioners you are likely to encounter; however,
you may find additional components in an
air-conditioner. Refer to figure 11-1 for the relative
locations of the major components.
The compressor used in a refrigeration and
air-conditioning unit has one purpose. It must withdraw
the superheat-laden, low-pressure refrigerant vapor
from the evaporator and compress it to such an extent
that it liquefies in the condenser. The design of the
compressor depends upon the application and type of
refrigerant used in the system. There are three types of
compressors, classified according to their principle of
Figure 11-2.--Compressor types.