Refrigerator User Manual

Introduction
With the phaseout of CFCs and HCFCs, existing
refrigeration and air-conditioning equipment operat-
ing with CFCs and HCFCs will ultimately need to
be either replaced with new equipment or retrofitted
with alternative refrigerants. Some service techni-
cians and equipment owners have elected to retrofit
to hydrofluorocarbon (HFC) refrigerants such as
Suva
®
134a, Suva
®
HP62, or Suva
®
507.
Using these procedures, R-12, R-502, and R-22
equipment can be safely and efficiently retrofitted
with HFC-based Suva
®
refrigerants, allowing the
equipment to continue in service for the remainder
of its useful life. These retrofit guidelines are in-
tended for equipment containing positive displace-
ment compressors.
R-12 Replacement Choices
Suva
®
134a (R-134a) is the long-term HFC re-
placement for R-12 in new equipment and for retro-
fitting some R-12 systems such as supermarket
display cases, commercial refrigeration and air-
conditioning equipment, appliances, and transport
refrigeration equipment. In stationary equipment
Suva
®
134a is recommended for retrofit of equip-
ment with evaporator temperatures above 20°F
(–7°C) to ensure best performance. Suva
®
134a
may be used in existing equipment at lower
evaporator temperatures, but it can exhibit
reduced capacity compared with R-12 unless
system modifications are made.
R-502 Replacement Choices
• Suva
®
HP62 (R-404A) is widely recognized as
the preferred HFC replacement for R-502 in new
equipment and for retrofitting R-502 systems such
as supermarket and food service, industrial
freezing, and some transport refrigeration. Suva
®
HP62 offers the closest HFC match to R-502
performance and can be used over the full R-502
operating range. Suva
®
HP62 also provides lower
compressor discharge temperatures than R-502,
which can increase compressor reliability and life.
• Suva
®
507 (R-507) is an HFC replacement
option for R-502 in new equipment and for
retrofitting R-502 systems. Suva
®
507 can also
be used over the full R-502 operating range, and
provides lower compressor discharge temperatures
than R-502, which can increase compressor
reliability and life.
• Suva
®
407C (R-407C) is also an HFC retrofit
option for R-502 in certain equipment. Refer to
ART-34 “Retrofit Guidelines for Suva
®
407C” for
details.
R-22 Replacement Choices
Suva
®
HP62 (R-404A) and Suva
®
507 (R-507) are
HFC retrofit options for R-22 refrigeration equip-
ment, especially for medium and low temperature
applications. These products will provide similar
cooling capacity at evaporator temperatures in the
range of 30°F to 50°F (–1°C to 10°C). At evapora-
tor temperatures below 30°F (–1°C), the cooling
capacity is greater than R-22. At 0°F (–18°C) the
capacity is about 6% higher; and at –40°F (–40°C)
the capacity is about 30% higher.
At evaporator temperatures above 10°F (–12°C)
there is an energy efficiency penalty of about 5
to 10%. At evaporator temperatures below 10°F
(–12°C) Suva
®
HP62 and 507 have similar energy
efficiency, increasing to about +20% at –40°F
(–40°C).
Suva
®
HP62 and 507 will have higher discharge
pressure than R-22, but lower compression ratios;
and also lower discharge temperature.
• Suva
®
407C (R-407C) should also be considered
as a retrofit option for R-22 in medium tempera-
ture equipment. It will provide similar cooling
capacity and energy efficiency at evaporator
temperatures above 25°F (4°C). Refer to ART-34
“Retrofit Guidelines for Suva
®
407C” for details
Using HFCs versus Service
Refrigerants
Refrigerants such as Suva
®
MP39, Suva
®
409A,
Suva
®
HP80 and Suva
®
408A are often selected
for retrofit instead of HFCs because these service
refrigerants typically involve an easier and more
cost-effective retrofit procedure while providing
improved performance over the CFCs they replace.
The compressor oil change procedures are typically
less complicated with the service refrigerants, which
results in lower retrofit costs. Refer to DuPont bul-
letin ART-36 “Retrofit Guidelines for Suva
®
Ser-
vice Refrigerants” for full details.
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