11. REFRIGERANT R410A:
SPECIAL PRECAUTIONS WHEN SERVICING UNIT
11-1. Characteristics of New Refrigerant R410A
11-1-1. What is New Refrigerant R410A?
R410A is a new refrigerant that contains two types of pseudo-non-azeotropic refrigerant mixture. Its
refrigeration capacity and energy efficiency are about the same level as the conventional refrigerant, R22.
11-1-2. Components (mixing proportions)
HFC32 (50%) / HFC125 (50%)
11-1-3. Characteristics
Less toxic, more chemically stable refrigerant
The composition of refrigerant R410A changes whether it is in a gaseous phase or liquid phase. Thus, when
there is a refrigerant leak the basic performance of the air conditioner may be degraded because of a change in
composition of the remaining refrigerant. Therefore, do not add new refrigerant. Instead, recover the remaining
refrigerant with the refrigerant recovery unit. Then, after evacuation, totally recharge the specified amount of
refrigerant with the new refrigerant at its normal mixed composition state (in liquid phase).
When refrigerant R410A is used, the composition will differ depending on whether it is in gaseous or liquid
phase, and the basic performance of the air conditioner will be degraded if it is charged while the refrigerant is in
gaseous state. Thus, always charge the refrigerant while it is in liquid phase.
Ether-type oil is used for compressor oil for R410A-type units, which is different
from the mineral oil used for R22. Thus more attention to moisture prevention and
faster replacement work compared with conventional models are required.
CAUTION
62