DuPont HP62, 507, 134A User Manual
Technical Information
ART-37
DuPont
refrigerants
Suva
®
Retrofit Guidelines for
Suva® HFC Refrigerants
Suva® 134a for R-12 Retrofit
Suva® HP62 and Suva® 507 for R-502 Retrofit
Suva® HP62 and Suva® 507 for R-22 Retrofit
The DuPont Oval Logo, DuPont™, The miracles of science™,
and Suva® are trademarks or registered trademarks of
E.I. du Pont de Nemours and Company.
Retrofit Guidelines for
Suva® HFC Refrigerants
Table of Contents
Page
Introduction ................................................................................................................ 1
R-12 Replacement Choices ..................................................................................... 1
R-502 Replacement Choices ................................................................................... 1
R-22 Replacement Choices ..................................................................................... 1
Using HFCs versus Service Refrigerants ............................................................ 1
Important Safety Information ................................................................................. 2
Lubricant and Filter Drier Information ................................................................ 2
Lubricants .................................................................................................................. 2
Filter Drier.................................................................................................................. 2
General Retrofit Information ................................................................................... 2
System Modifications ................................................................................................ 2
Refrigerant Recovery Information ............................................................................. 3
What to Expect Following a Retrofit.......................................................................... 3
Retrofit Summary for HFC Refrigerants.................................................................... 4
Retrofit of R-12 Systems to Suva® 134a ............................................................ 4
Retrofit of R-502 Systems to Suva® HP62 or Suva® 507 ............................... 5
Retrofit of R-22 Systems to Suva® HP62 or Suva® 507 ................................. 6
Pressure/Temperature Charts—Introduction ........................................................ 8
How to Read the Pressure/Temperature Charts ....................................................... 8
How to Determine Suction Pressure, Superheat, and Subcool................................. 8
Retrofit Checklist for Suva® 134a, Suva® HP62, or Suva® 507 ...................... 9
System Data Sheet ................................................................................................. 10
Appendix
Table 1. Pressure/Temperature Chart—Suva® 134a/R-12..................................... 11
Table 2. Pressure/Temperature Chart—Suva® HP62/R-502.................................. 12
Table 3. Pressure/Temperature Chart—Suva® 507/R-502..................................... 13
Table 4. Pressure/Temperature Chart—Suva® HP62/R-22.................................... 14
Table 5. Pressure/Temperature Chart—Suva® 507/R-22....................................... 15
Table 6. Suva® 134a Physical Properties ............................................................... 16
Table 7. Suva® HP62 and Suva® 507 Physical Properties ..................................... 16
Table 8. Compositions of Suva® Refrigerants ........................................................ 16
DuPont Technical Assistance and Other Information .............................back page
Introduction
With the phaseout of CFCs and HCFCs, existing
refrigeration and air-conditioning equipment operating with CFCs and HCFCs will ultimately need to
be either replaced with new equipment or retrofitted
with alternative refrigerants. Some service technicians 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
equipment to continue in service for the remainder
of its useful life. These retrofit guidelines are intended for equipment containing positive displacement compressors.
R-12 Replacement Choices
Suva® 134a (R-134a) is the long-term HFC re-
placement for R-12 in new equipment and for retrofitting some R-12 systems such as supermarket
display cases, commercial refrigeration and airconditioning equipment, appliances, and transport
refrigeration equipment. In stationary equipment
®
Suva
134a is recommended for retrofit of equipment with evaporator temperatures above 20°F
(–7°C) to ensure best performance. Suva
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
compressor discharge temperatures than R-502,
wh i ch 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
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.
®
refrigerants, allowing the
®
134a
®
HP62 also provides lower
®
507 can also
®
• 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 equipment, 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 evaporator 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).
®
HP62 and 507 will have higher discharge
Suva
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 temperature 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 bulletin ART-36 “Retrofit Guidelines for Suva
vice Refrigerants” for full details.
®
Ser-
1
Important Safety Information
Like CFCs, Suva® refrigerants are safe when
handled properly. However, any refrigerant can
cause injury or even death when mishandled. Please
review the following guidelines before using any
refrigerant.
• Do not work in high concentrations of refriger-
ant vapors. Always maintain adequate ventilation
in the work area. Do not breathe vapors. Do not
breathe lubricant mists from leaking systems.
Ventilate the area well after any leak before
attempting to repair equipment.
Lubricant and Filter Drier
Information
Lubricants
Lubricant selection is based on many factors, including compressor wear characteristics, material
compatibility, and lubricant/refrigerant miscibility
that can affect oil return to the compressor. Before
starting a retrofit, consult the compressor manufacturer to determine the correct lubricant for your
compressor. Other information sources are DuPont
Refrigerant Distributors, lubricant manufacturers,
and system manufacturers.
• Do not use handheld leak detectors to check for
breathable air. These detectors are not designed
to determine if the air is safe to breathe. Use
oxygen monitors to ensure adequate oxygen is
available to sustain life.
• Do not use flames or torches to search for
leaks. Do not use flames in high concentrations
of refrigerant. Open flames release large quantities
of acidic compounds in the presence of all refrigerants, and these compounds can be hazardous.
Do not use torches as leak detectors. Old halide
torches detect chlorine, which may not be present
with new refrigerants. Use an electronic leak
detector designed to find the refrigerants you
are using.
If you detect a visible change in the size or color
of a flame when using torches to repair equipment, stop work immediately and leave the
area. Ventilate the work area well and stop any
refrigerant leaks before resuming work. These
flame effects may be an indication of very high
refrigerant concentrations, and continuing to work
without adequate ventilation may result in injury
or death.
Polyol ester (POE) lubricants must be used with
®
Suva
134a, Suva® HP62 or Suva® 507 refrigerants. These lubricants are available from DuPont
Refrigerant Distributors. To provide optimum oil
return, equipment using mineral oil or alkylbenzene
must be flushed to remove at least 95% of these
oils. See the retrofit procedures below for more
information.
Special care should be taken when handling POE
lubricants because of their tendency to absorb water. Minimize contact with air and store the lubricant in a sealed container.
Filter Drier
Change the filter drier during the retrofit. This is a
routine practice following system maintenance.
There are two types of filter driers commonly used,
solid core and packed bead.
Replace the drier with the same type you currently
use. The drier label will show which refrigerants can
be used with that drier. Check with your DuPont
Refrigerant Distributor for the correct drier to use
in your system.
Note: Any refrigerant can be hazardous if used
improperly. Hazards include liquid or vapor under
pressure, and frostbite from the escaping liquid.
Overexposure to high concentrations of vapor
can cause asphyxiation and cardiac arrest. Please
read all safety information before handling any refrigerant.
For more detailed information on the properties,
uses, storage, and handling of Suva
®
refrigerants,
see DuPont Technical Bulletin P-134a or P-HP, or
other literature specific to these products. Refer to
the appropriate Material Safety Data Sheet (MSDS)
for more safety information about each refrigerant.
DuPont Safety Bulletin AS-1 gives additional information for safe handling of refrigerants.
General Retrofit Information
System Modifications
The compositions of these Suva® refrigerants have
been selected to provide performance comparable
with the refrigerants they are replacing in terms of
both capacity and energy efficiency. As a result,
minimal system modifications are anticipated
with retrofitting. Suva
near-azeotropes at most temperatures, therefore the
vapor composition in the refrigerant cylinder is
slightly different from the liquid composition.
This small difference will not affect performance
in direct expansion systems, but it could affect performance in systems with flooded evaporators.
2
®
HP62 and Suva® 507 are
You should consult the original equipment manufacturer for recommendations concerning the compatibility of elastomers and plastics used in their system
and the new refrigerant. Although many system
components used with CFCs are also compatible
with Suva
®
refrigerants, there are exceptions that, if
not replaced, can cause refrigerant leakage or system failure.
Field experience has shown that some systems
®
retrofitted directly from R-502 to Suva
or Suva
®
507 can have increased leakage due to
HP62
shrinkage of elastomers (o-rings, gaskets) following removal of the R-502. This same situation
might exist in an R-22 retrofit. Replacement of
these elastomers may add additional cost and
time to the retrofit.
Retrofits of R-12 or R-502 systems with other alternative refrigerants such as HCFC-22 may require
more extensive modifications to the existing equipment, such as replacement of the compressor with
multistage compressors or use of liquid injection.
For some systems this additional cost may be large.
®
Suva
refrigerants provide the service contractor
and equipment owner with a cost-effective way to
retrofit an existing system.
®
Note: Suva
refrigerants were not designed for use
in conjunction with other refrigerants or additives
that have not been clearly specified by DuPont or
the equipment manufacturer. Mixing Suva
®
refrigerants with other refrigerants, may have an adverse
effect on system performance. “Topping off” a
different refrigerant with any Suva
®
refrigerant is
not recommended.
In the United States, DuPont will take back for
®
reclaim the Suva
refrigerants discussed in this
bulletin.
What to Expect Following a Retrofit
These tables show approximate system performance
changes following a retrofit. These values are general guidelines for system behavior, and actual performance will vary with each system.
®
134a is compared to R-12, Suva® HP62 and
Suva
®
507 are compared to R-502.
Suva
Disch. Suct. Disch. Refrig.
®
Suva
Refrig. psi (kPa) psi (kPa) °F (°C) (% )
134a +10 –2 –10 –10
HP62 +20 Same –10 Same
507 +30 Same –15 Same
Suva® HP62 is compared to R-22 (evap. temp. =
0°F [–18°C]). Note: Suva
mance very similar to HP62.
Suva
Refrig. psi (kPa) psi (kPa) ( %) °F (°C) (% )
HP62 +45 +10 –5 –64 +6
Press. Press. Temp. Cap’y.
(69.8) (–13.8) (–5.6)
(+137.9) (–5.6)
(+206.8) (+8.3)
®
507 provides perfor-
Disch. Suct. Compression Disch. Refrig.
®
Press. Press. Ratio Temp. Cap’y.
(+310) (+69.8) (–36)
Refrigerant Recovery Information
Most recovery or recycle equipment used for R-12,
R-502, or R-22 can be used for Suva
Use standard procedures to avoid cross-contamination when switching from one refrigerant to another.
Consult the equipment manufacturer for specific
recommendations.
®
refrigerants.
How to read these tables
Example: R-12 to Suva
with 134a will be in the range of 10 psig higher than R-12
(using discharge pressure column above).
®
134a retrofit. Discharge pressure
3
Retrofit Summary for HFC
Refrigerants
Select the Retrofit Checklist from the Appendix for the refrigerant you are replacing.
1. Establish baseline performance with
CFC/HCFC.
2. Drain mineral oil or alkylbenzene (MO/
AB) from the system and measure the
volume removed. Leave the CFC/HCFC
refrigerant in the system.
3. Add POE lubricant; use the same volume
as removed in Step 2. Start up system and
operate for at least 24 hours, or more if
system has complex piping.
4. Drain POE, and repeat steps 2 and 3 at
least two more times. Continue flushing
until MO/AB is less than 5% by weight
or as recommended by compressor
manufacturer.
5. Recover the CFC/HCFC charge into a
proper recovery cylinder.
6. Replace the filter/drier.
7. Evacuate system and check for leaks.
®
8. Charge with Suva
refrigerant. Remove
liquid only from charging cylinder for
®
Suva
HP62 or Suva® 507. Typical
charge is 75–90% by weight of
CFC/HCFC charge.
9. Start up system, adjust charge size. Label
system for the refrigerant and lubricant
used.
Retrofit Complete
Retrofit of R-12 Systems to
®
Suva
The following detailed discussion is the recommended procedure for retrofitting R-12 systems
to Suva
1. Establish baseline performance with CFC.
134a
®
134a.
Collect system performance data while the
R-12 is in the system. Check for correct refrigerant charge and operating conditions. The
baseline data of temperatures and pressures at
various points in the system (evaporator,
condenser, compressor suction and discharge,
superheat and subcool, etc.) at normal operating
conditions will be useful when optimizing
operation of the system with the Suva® refrigerant. A System Data Sheet is included at the
back of this document to record baseline data.
2. Drain mineral oil or alkylbenzene from the
system and measure the volume removed.
Leave the CFC refrigerant in the system.
If mineral oil or alkylbenzene is the existing
lubricant, it will have to be drained. This may
require removing the compressor from the
system, particularly with small hermetic compressors that have no oil drain port. In this case,
the lubricant should be drained from the suction
port on the compressor after the R-12 has been
properly recovered. For an effective flush, it is
important to remove at least 50% of the lubricant in all cases. Larger systems may require
drainage from additional points in the system,
particularly low spots around the evaporator.
In systems with an oil separator, any lubricant
present in the separator should also be drained.
In all cases, measure the volume of lubricant
removed from the system. Record this information on the Retrofit Checklist (see Appendix).
Compare this volume with the compressor/
system specifications to ensure that the majority
of lubricant has been removed. Consult the
compressor manufacturer for recommendations
on allowable residual MO/AB in POE lubricant.
If poor system performance is noted on start-up,
an additional lubricant change may be required.
3. Add POE lubricant; use the same volume
as removed in Step 2. Start up system and
operate for at least 24 hours, or more if
system has complex piping. Charge the com-
pressor with the same volume of new lubricant
as the amount you removed from the system in
step 2. Use a lubricant viscosity and grade
recommended by the compressor manufacturer
for the Suva
®
refrigerant you are using; or use a
similar viscosity to the oil you
removed if compressor information is not
available. A typical viscosity is 150 SUS or
ISO 32 for many compressors.
4. Drain POE, and repeat steps 2 and 3 at least
two more times. Continue flushing until MO/
AB is less than 5% by weight or as recommended by compressor manufacturer. For
an HFC refrigerant to operate properly in a
retrofitted system, the residual MO/AB concentration must be very low. Repeatedly removing
and replacing the POE will flush the old oil
from the refrigeration system, providing that
enough time is allowed with each change to
circulate oil through the entire system.
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