Mitsubishi SRK20ZSX-W User Manual

'18 • SRK-T-234
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146
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(1) Outline
1-1) R32 as the alternative refrigerant for residential air-conditioners.
As for the R410A refrigerant which we have been usually using for air-conditioners, in case of emissions into the atmo
-
sphere, we have been adopting the collection of refrigerant etc. in order to restrain the world from global warming.
Based on the 4th basic ecological plan, it is said that the amount of emission of the green house ef
fect gases including the
refrigerants which are being used for air-conditioners shall be reduced 80% by 2050, emissions of any kind of freon gases
which have especially high global warming coefcient must be reduced much more.
Hence, it is required to converted the freon gases we are using for air-conditioners into the refrigerants which have lower
global warming even though they are exhausted into the atmosphere.
On the other hand, the refrigerants for air-conditioners, lower effect of global warming, to secure its performance and high
energy efciency and safety are required, however, the refrigerants which satisfy all of them have not been announced yet.
For this purpose, we have been studying to make use of the refrigerant like R32 which has short life in the atmosphere, even
though it has low global warming but low combustibility under the practical use for safety.
In 2004, IEC, international electrical safety for air-conditioners had been corrected, the regulation for safety of air-condition
-
ers which use the combustible refrigerant have been issued, in 2010, the regulation adopting the degree which is considered
to
be damaged slightly because of difculty of ignition due to its low combustion speed was issued in ANSI/ASHRAE34
regulations.
R32 has been approved as the refrigerant whose combustion speed degree is lower than 10cm/sec, the standardization for
safety use is being proceeded so that R32 can be used more widely.
Although all the air-conditioners which use R32 have been designed with deep consideration in order to guarantee the safe
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ty, some cautions which are mandatory to be kept during its installation and services are shown as follows.
1-2) Chemical characteristics of R32
(
i
) Chemical charactaristic
R32
is one of an ingredient which composes R410A, without toxicity, the chemically stable compound which consists
of carbon and uorine.
Life of R32 after diffusing in the atmosphere is very short, approximately 4.9 years, as a result, although the effect to
global warming can be reduced, there are little combustible due to large ratio of hydrogen.
(
ii
) Pressure charactaristic
As mentioned in table 2, vapor pressure of R32 is almost same as R410A under the identical refrigerant temperature,
and it has 1.6 times of high performance comparision with R22.
Therefore, tool and apparatus which are intended to be used under high pressure condition shall be required same as
R410A when service and installation are implemented.
R32 R410A R22
Chemical formation CH
2
F
2
CH
2
F
2
/CHF
2
CF
3
CHCLF
2
Composition
(Mixture ratio weight%)
Single composition
R32/R125
(50/50 weight%)
Single composition
Boiling point -51.7
℃
-51.5
℃
-40.8
℃
Pressure at 50
℃
3.14 3.07 1.94
Performance at 0/50
℃
160 141 100
COP at Te/Tc/SC/SH=5/50/3/0
℃
95 91 100
ODP(Ozone Depletion Potential) 0 0 0.055
GWP(Global Warming Potential) 675 2090 1810
Combustible charactarictic A2L A1 A1
Toxicity No No No
14. REFERENCE

Mitsubishi SRK20ZSX-W Specifications

General

Brand	Mitsubishi
Model	SRK20ZSX-W
Category	Air Conditioner
Language	English