Valtra VALMETSERIES Service Manual - Operating Principle
The air conditioner functions so that the refrigerant is
continuously circulated in the system at which time it
changes from liquid form into gaseous form. This pro-
cess absorbs heat from the cab when the refrigerant
vaporises in the evaporator and emits heat to outdoors
when refrigerant becomes condensed in the condenser.
Although the process has four parts, it can be divided
into two main parts: high pressure side and low pressure
side according to the figure below.
Figure 1. Operating principle of air conditioner
High pressure side
Low pressure side
Expansion valve
Compressor
Condenser
Evaporator
Heat is trans-
ferred from
cab to refrige-
rant
Heat is trans-
ferred from
refrigerant to
outdoors
Drier
1137
Model
Code
Page
83. Air conditioner
1. 1. 1994
6000--8750
830
3
15. 6. 1992
Operating principle
An air conditioner takes heat from the cab air when outdoor
temperature is high. Refrigerant in the system is exposed
under different pressures and temperatures and this causes
a cooling effect. Refrigerant vaporizes in the evaporator and
evaporation absorbs heat which is taken from the warm cab
air which is blown through the evaporator.