Refrigerant Retrofitting

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REFRIGERATOR RETROFITTING

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What is retrofit in the field of refrigeration?

• Retrofit is the process by which the equipment currently using an ODS refrigerant is made to run on a non-ODS refrigerant, without major effects on the performance of the equipment, and without significant modifications/changes for the equipment, ensuring that existing equipment operates until the end of its economic life.

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WHY RETROFIT

• Imminent CFC-shortages would threaten the useful life of the appliances of CFC-equipment.

• As CFC shortages increase, the cost of CFCs will rise, along with operating costs of the equipment. Retrofit refrigerants and technology are available for most applications.

• By retrofitting the equipment, you enable it to operate past the CFC's phase-out dead lines, and the equipment lifetime exceeds the phase-out dates.

• Existing plants which have reached the end of their economic lifetime, should be replaced with new refrigeration equipment based on non-ODS refrigerants and technologies.

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The Need for New Refrigerants

• The phaseout of CFCs and HCFCs creates the urgent need for nontoxic, nonflammable, environmentally safe refrigerants with high energy efficiency and capacity.

• The ideal refrigerant should have the following properties: 1. High energy efficiency2. High refrigeration capacity3. Nonflammability4. Low toxicity5. Zero ODP6. Very low (GWP) and total equivalent warming impact (TEWI), 7. Ability to use existing proven compressors and other

components8. Low cost.

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Desired Refrigerant Properties• Environmentally acceptable• Non-toxic• Non-flammable• High latent heat vaporization• Material of construction compatible (hoses)• Lubricant soluble• Low moisture solubility• Ease of transport handling• Capable of recycling• Detectable at low concentrations• Reasonable cost• Field system charging capability

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FACTORS INFLUENCING THE TIMING & RATE OF CFC REPLACEMENT

• Key factors which influence the timing and the rate of CFC replacement include: – Lifetime of the Equipment and Servicing

Needs – Retrofit Possibilities for Existing Equipment – Product Energy Efficiency – Toxicity, Flammability, and Environmental

Concerns

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MONTREAL PROTOCOL• In September 1987, the first worldwide step toward controlling ozone

depletion was established with the Montreal Protocol on Substances that Deplete the Ozone Layer.

• Montreal Protocol – an international accord to reduce and eventually eliminate the emissions of man-made ozone depleting substances.

• Its control provisions were strengthened through four adjustments to the Protocol adopted in London (1990), Copenhagen (1992), Vienna (1995), and Montreal (1997).

• To become a party – a nation must enact legislation and adopt regulations to put into force legal instruments that will achieve the Protocol’s objectives and meet its requirements for becoming a party.

• 175 countries have ratified the Protocol.

• The Montreal Amendment entered into force on January 1, 1999.

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CHEMICALS LISTED IN THE MONTREAL PROTOCOL

• Class 1 Substances

• Group I: Fully-Halogenated Chlorofluorocarbons

– CFC-11 CFC-12 CFC-113

– CFC-114 CFC-115

• Group II: Halons (Fire suppression systems)

– Halon-1211 Halon-1301 Halon-2402

• Production of Group I & II refrigerants are frozen at 1986 levels as of 1989 and 1992.

• Phaseout of CFCs (Class I Substances)

• CFC Production Phased-out January 1, 1999

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Table 2: Environmental Impact of Refrigerants

Refrigerant ODP GWP Comments

CFC-11 1 4000

CFC-12 1 8500

CFC 500 0.66 6300 CFC-12 + HFC-152a

CFC-502 0.28 5600 HCFC-22 + CFC-115

HCFC-22 0.055 1700

HCFC-123 0.02 93

HFC-134a 0 1300

R41OA 0 1890 HFC-32 + HFC-125

Propane 0 3 Very flammable

Ammonia 0 0 Toxic and flammable ODP Ozone depletion potential relative to CFC-11 = 1 GWP = Global warming potential relative to CO2 = 1 (100-yr time horizon basis)

Source BRE

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EMMISSIONS & PROTOCOLSEffect of the International Agreements on Ozone-Depleting

Stratospheric Chlorine/Bromine

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RETROFIT STUDY INFORMATION

• Retrofit study involves the joint effort by equipment manufacturer, equipment owner, service agency, refrigerant manufacturer and research institute.

Study and experiments on retrofitting have to address the following problems

• Technical• i) Pressure and temperature level, performance and capacity

• ii) Compatibility of lubricants and refrigerants with construction, sealing and insulation materials

• iii) Refrigerant and lubricant solubility (eg. capillary tube plugging)

• iv) Chemical and humidity residues and their impact on lubricants, refrigerants, materials and operation performance

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• Typical retrofit may involve one or many of the following changes/justifications:

Lubricant

Desiccant filter (dryer)

Expansion valve

Compressor (gearbox, speed, motor)

Insulation and seal materials, elastomers

• For centrifugal chillers: purge systems, impeller/gearbox

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• RETROFITTING WITH NON-CFC SUBSTITUTES

• Storage/handling of lubricants and refrigerants, with regard to moisture interaction

• Redesign of compressor and other components

• Field tests/reliability

• Others

• Time consumption for retrofitting

• Cost of retrofitting (equipment, lubricant, refrigerant)

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GENERAL TERMS USED

• Drop-In Replacement - An alternative refrigerant that can be installed directly into an existing system with minor equipment changes. Most interim alternatives fall into this category.

• Interim Replacements (SHORT TERM) - Any of a number of refrigerants intended to serve as an intermediate solution during the transition from CFC to HFC refrigerants. Most interim replacements contain HCFC refrigerants like R22.

• Long Term Replacements - Alternative refrigerants that are considered to have no adverse affect on the stratospheric ozone layer. Most long term replacements are HFC compounds.

• Medium Pressure Refrigerant (MP) - A term used for some alternative refrigerants designed to operate in the medium temperature (0° F to 4° F) range.

• High Pressure Refrigerants(HP) - A term used for some alternative refrigerants designed to operate in the low temperature (-35° F to 0° F) range.

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The Eight Easy Steps to Retrofit

• Select the Retrofit Checklist from the Appendix for the refrigerant you are replacing.

i. Establish baseline performance with CFC.

ii. Remove CFC from the system into a recovery cylinder. Weigh the amount removed if possible.

iii. Drain mineral oil from the system and measure the volume removed. (Skip steps 3 and 4 if AB lubricant is already in the system or you are not changing the mineral oil).

iv. Add AB lubricant; use the same volume as removed in Step 3

v. Replace the filter/drier/ piping, controls, EV Compressor if required.

vi. Evacuate system and check for leaks.

vii. Charge with Suva® refrigerant. Remove liquid only from charging cylinder. Typical charge is 75–90% of CFC charge.

viii. Start up system, adjust charge size. Label system for the refrigerant and lubricant used.

Retrofit Complete

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RETROFITTING PROCEDURE

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• 100 Select facility to retrofit with alternative refrigerant.

First activity in the retrofit process.

• 110 Evaluate existing refrigeration system.

Evaluate the current refrigeration system

Review as-built documents, facility visit and investigation.

Consider the cooling demands of the facility, and capacity of the existing system.

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• 120 Design equipment and piping for use with new refrigerant.

Objective is to maintain adequate refrigeration capacity & minimizing retrofit cost

Consider each piece of equipment & critical piping runs in the system with the alternative refrigerant.

For example, conversion of existing R-12 and R-502 systems to R-22 involves the change of compressor bodies and associated valves and controls, a change of expansion valves, and a modification to suction and liquid lines, especially at risers.

Determine what equipment and piping must be replaced.

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• 130 Consider and design other system changes.

Consider other changes to the refrigeration system that may prove beneficial to the operation.

For example, excessive refrigerant losses in the existing system

Replace old piping and valves, or install a leak-detection system.

• 140 Prepare equipment and material list for purchasing.

Identify all items that must be purchased.

150 Purchase materials and equipment.

Pursue the most favorable pricing while satisfying the specifications.

Execute purchase orders.

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• 160 Deliver materials and equipment.

Deliver equipment and materials directly to the facility.

• 200 Notify retail operations of installation date.

Notify the retrofit installation plan and schedule

Ensure that the retrofit operation is well coordinated.

• 205 Start retrofit work at facility.

• 170 Cut and prepare for installation of new risers.

Try to minimize the impact of retrofitting on the system operations.

Perform the liquid and suction riser work can be during normal operating hours.

Preliminary riser work does not require shutting down the refrigeration system.

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• 180 Install new risers. After the cutting and preparation for the installation of the new risers is

completed, the risers can be installed. The risers are installed alongside the existing risers. Make piping connections after shutting down the system and evacuating

refrigerant.

• 210 Retail operations empty product from cases. Remove all food products from the refrigerated cases that are

connected to the compressor rack to be retrofitted. The food is temporarily stored in another refrigerated area.

• 220 Shut down compressor rack. After the food products have been relocated, the compressor rack can

be shut down. Disconnect the power at the electrical panel

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• 230 Evacuate and recover CFC refrigerant. Recover CFC refrigerant from the system through both high and low-

side ports. Store recovered refrigerant is in an external tank. Do not vent any CFC refrigerant into the atmosphere (penalties may be

imposed). Recover refrigerant without any losses. Remove Lubricant

• 240 Haul recovered CFCs to reclamation center. After the modified system has been started up and balanced.

• 250 Reclaim CFC refrigerant. Reprocess the hauled refrigerant to new product specifications. Chemical analysis to determine that appropriate product

specifications are met

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• 260 Store reclaimed CFC refrigerant for service use. Store in a secured warehouse for future use in service

applications. Until an organization has completely retrofitted all of its CFC

applications, it needs additional CFC refrigerant for service applications.

• 270 Remove existing compressors from system. After the CFC refrigerant has been evacuated and recovered,

disconnect and remove the existing compressors from the equipment pad.

• 280 Install new compressors. For use with Alternative refrigerant (R-22) can be installed on

the pad. Replace Seals/O-rings, hose material, compressor, desiccant,

condenser, refrigerants controls, lubricant if required

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• 300 Install new pressure relief valve on receiver.

Differences in operating liquid refrigerant pressures between R-22 and R-12 or R-502, it is necessary to install a new pressure relief valve on the liquid refrigerant receiver when performing the retrofit.

• 310 Remove existing expansion valves.

In every retrofit, all expansion valves must be replaced.

• 320 Install new expansion valves.

Install the new expansion valves

• 330 Make piping connections.

After the compressors have been installed, make all piping connections.

These connections include those at the compressor, at the new risers, and anywhere else in the system where piping is being replaced.

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• 340 Leak check system. Evacuate the system & leak test. This involves pulling a vacuum through the system at the service

valves. Leak checking can be done using a standing pressure test. Nitrogen is commonly used as the pressure source.

• 350 Insulate piping and patch at new risers. After the system has passed leak testing, required insulation can

be installed on new piping sections. Also, the cut area where the new risers have replaced the old

ones should be patched as necessary.

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• 360 Introduce new Refrigerant Charge into the system. After the leak test, introduce the new refrigerant charge into the

system.

• 370 Reprogram electronic controls for new refrigerant . Because the retrofit system will operate at different pressures and

corresponding temperatures at various points in the cycle, it is necessary to reprogram the electronic controls accordingly.

• 380 Startup and balance system. Reprogram the electronic controls, startup and balancing of the

system. Startup requires greater attention to operating temperatures. Operation at high temperatures during startup can shorten

compressor life. be Coordinate and test settings of relief valves, HP/LP safety switches, and computer-controlled high-pressure shutdown.

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• 390 Monitor revised system operation.

Monitor the retrofit system during the first several hours of operation.

Check operating temp./press., cooling capacity, COP, Leakages, EER

• 400 Restock refrigerated cases.

After balancing and testing Restock the retrofitted cases.

• 410 Refrigerant retrofit complete.

Finally, after all retrofit tasks have been performed, the

refrigerant retrofit is complete.

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ALTERNATIVE REFRIGERANTS

Product Application Comments

To Replace R-12 and R-500

Service Refrigerants (HCFC)

Suva® MP39(R-401A)

Retrofit R-12Medium/low temp., best above -15°F evap.

Preferred retrofit option for R-12. No oil change for small close-coupled systems.

Suva® MP66(R-401B)

Retrofit R-500, R-12Higher capacity for low-temp. R-12, best below -15°F evap.

R-500 quick, cost-effective retrofit; one oil change.R-12 retrofit where higher capacity is needed at low temp. No oil change for small close-coupled systems.

Long Term (HFC)

Suva® 134a(R-134a)

New Equipment and RetrofitR-12Medium temp.

Good option for new equipment. Also retrofit option; best above 20°F (-7°C) evap.; MP39 less costly option for retrofit.

http://www.dupont.com/suva/emea/products/suvamp39.html

http://www.dupont.com/suva/emea/products/suvamp66.html

http://www.dupont.com/suva/emea/products/suva134a.html



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Conversion Capacity & Efficiency Losses

The following has occurred:

Conversions Capacity Loss Efficiency Loss

CFC-11 to HCFC-123 2%-15% 7%-20%

CFC-12 to HFC-134a Negligible Negligible

Conversion capacity losses and efficiency loss are dependent on the specific piece of equipment converted and the details of what is actually replaced during the conversions, such as impellers, gears, etc.

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CFC-11 Replacement HCFC-123

• Blend refrigerant

• Short term alternative

• Contains chlorine

• Ozone Depletion Potential (ODP) of 0.03

• (R-11 is 1.0)

• Can tolerate up to 20% mineral oil

• Use alkylbenzene synthetic oil

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CFC-12 Replacement HFC-134a

• Contains no chlorine

• Zero Ozone Depletion Potential (ODP)

• Medium and high temperature applications

• Used in automotive applications

• Cannot use mineral oils or be retrofitted

• Low Global Warming Potential (GWP) of 0.26

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ALTERNATIVE REFRIGERANTS

Product Application Comments

To Replace R-22Long Term (HFC)

Suva® 407C(R-407C)

New Equipment and Retrofit - A/C and Heat PumpsAvailable today for retrofit and new equipment.

Suva® 410A(R-410A)

Only for Equipment Designed for 410A - A/C and Heat Pumps

High pressure/high efficiency refrigerant of the future; only for equipment designed for R-410A.Often referred to as AZ-20.

To Replace R-11Suva® 123(R-123)

Low-press. chillers, engg. modifications may be required.

http://www.dupont.com/suva/emea/products/suva407c.html






http://www.dupont.com/suva/emea/products/suva123.html



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CFCs

Color Gas type Chemical Name Container sizes Application Oil type

.11 Tricholorofluoromethane

100lb200lb

CentrifugalsMineral

Alkylbenzene

white 12 Dichlorodifluoromethane

12oz30lb50lb

145lb

Med & Hi temp Refrig.& Auto

MineralAlkylbenzene

.13 Chlorotrifluoromethane

9lb23lb80lb

Ultra lowtemp

refrigeration

MineralAlkylbenzene

.113 Thrichlorotrifluoroethane

100lb200lb

Comm. IndustA.C.

MineralAlkylbenzene

.114 Dichlorotetrafluoroethane 150lb

Ind. ProcessCentrifugals

MineralAlkylbenzene

.500 12/152a blend

30lb125lb

Comm. A.C.Mineral

Alkylbenzene

.502 22/115 blend

30lb50lb

125lb

Med & lowTemp Ref

MineralAlkylbenzene

.503 13/23 blend

8lb20lb80lb

Ultra lowtemp refrig.

MineralAlkylbenzene

REFRIGERANT DESCRIPTION

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HCFCs

Color Gas type Chemical Name Container

sizes Application Oil type

. 22 Chlorodifluoromethane

30lb-singles

30lb-pallets 50lb,125lb

A.C. & Low &Med

temp Ref.

Mineral Alkylbenzene Polyol Ester

. 123 Dichlorotrifluoroethane 100 lb, 200lb

Low Pressure Centrifugals

Mineral Alkylbenzene

. 401A (MP39) 22/124/152a blend 30lb, 125lb Med Temp

refrigeration Alkylbenzene Polyol Ester

. 401B(MP66) 22/124/152a blend 30lb, 125lb Low Temp

refrigeration Alkylbenzene Polyol Ester

. 402A(HP80) 22/125/290 blend 27lb, 110lb Low & Med

Temp refrigeration

Alkylbenzene Polyol Ester

. 416A/FR-12 134a/124/600blend 9.6oz 25lb

125lb

Mobile, A.C. & Med. Temp. Ref & Chillers

Mineral Alkylbenzene Polyol Ester


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HFCs

Color Gas type Chemical Name

Container sizes

Application Oil type

. 23 Trifluoromethane 9lb 20lb

Ultra Low Temp. Ref.

Polyol Ester

. 134a Tetrafluoroethane 30lb

125lb 1000lb

A.C. & Med. Temp. Ref

Polyol Ester

. 404A

(FX70/HP62) 125/134a/143a

blend 24lb, 100lb Low & Med. Temp. Ref.

Polyol Ester

. 507

(AZ50) 125/143a blend 25lb

100lb Low & Med. Temp. Ref.

Polyol Ester


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OILS USED

• Ester Oil - A general term that applies to a family of synthetic refrigeration oils based on the chemistry of polyol esters. Ester oils are generally regarded as the oil to use with most of the alternative refrigerants. Ester oils are generally compatible with existing mineral oils, and system components. Ester oils are slightly hygroscopic and should be in non-porous containers.

• P.A.G. Oil - A general term that applies to a family of synthetic oils based on the chemistry of Poly-alkyline glycols. The primary application of P.A.G. oils will be for automotive air conditioning.

• Alkyl Benzene Oil - A synthetic refrigeration oil commonly known as Zero.

• Mineral Oil - Refrigeration oil currently in use but is not compatible with most of the alternative refrigerants. Refrigerant conversions often require. a procedure for the removal of existing mineral oil because of the incompatibility with alternative refrigerants.

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COMPATIBILITY

• Assure oil is compatible with refrigerant.

• Assure refrigerant is compatible with equipment components.

• Assure recovery unit is compatible with refrigerant and oil.

KNOW WHAT REFRIGERANT, OIL, AND COMPONENT MATERIAL YOU ARE

WORKING WITH

(Look at unit name plate)

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Suggested Oil Guide

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RETROFIT EXAMPLE

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HFC-134a retrofit for CFC-12

• Check system. Includes leak detection and identifying other part failures.

• Remove R-12 from the system• Lubricant removal• Retrofit part replacement. (Seals/O-rings, hose material,

compressor, desiccant, condenser, refrigerants controls, lubricant.)

• Install service ports• System labels• System evacuation• Charge system with R-134a• Leak check system• Check system operation

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HFC-134a AS RETROFIT FOR R-12

• HFC-134a is a leading candidate in replacing CFC-12 in refrigerators and freezers.

• Benefits

R- 134a is ideal non-flammable, zero-ODP replacement for R-12.

HFC-134a is an environmentally acceptable alternatives that is low in toxicity, non-corrosive and compatible with other materials.

Energy consumption of the HFC-134a refrigerator equalled that of CFC-12.

Thermal performances met national standards.

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• Problems:• Studies show from 1% less to 7% higher energy consumption

than CFC-12. • Immiscible with mineral oils traditionally used with R-12.• HFC-134a has very low solubility and mineral oil does not mix

well in HFC-134a, which could contribute to the following problems: Poor oil return back to the compressor, resulting in possible

compressor failure Fouling of expansion valves and heat exchanger surfaces,

leading to reduced system performance

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• PAGs have to be used, but revealed an inherent and significant problem, namely high hygroscopicity.

• Improved lubrication and better handling characteristics achieved with use of synthetic polyol ester oils.

• Synthetic polyol ester lubricants are well suited for use with R-134a.

• Problems regarding accurate cleaning of the old system, redesign of the compressor and matching of each component

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OILS CHANGE PROCEDURE

• Where possible, use OEM-recommended oil type, charge size, and viscosity.

• The oil change procedure is as follows:

The mineral oil is drained from the compressor.

The compressor is filled with polyol ester oil and run for 24 hr or more.

A longer run time provides better flushing of the oil from the system.

A sample of the oil is removed and tested for contamination levels of mineral oil & metal wear.

The system is again drained, refilled, and run with fresh polyol ester oil for 24 hr or longer. Contamination levels are once again determined.

This procedure is repeated, if necessary, until mineral oil contamination is under 5 percent (usually 2 or 3 oil changes total).

The system may then be evacuated of R-12 and charged with R-134a, assuming that all necessary modifications have been made.

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Material Compatibility

• R-134a and polyol ester lubricants tested for a variety of factors, such as material swell, material shrinkage, hardening, elasticity changes, refrigerant permeation

• In general, the following applies:• (1) Metals. R-134a and polyol esters are compatible with all metals

typically found in airconditioning systems.• (2) Plastics. R-134a and polyol esters are compatible with most

plastics found in R-12 systems. Acrylics and celluloses should not be used with R-134a.

• (3) Elastomers (seals, gaskets, o-rings, etc.). R-134a and polyol esters are compatible with many elastomers found in R-12 systems. Adiprene L and Viton A should not be used with R-134a.

Because Buna S and butyl rubber exhibit borderline characteristic changes, their use with R-134a is not recommended.

Styrenated butadiene (SBR) exhibits a high swell with polyol ester and is not recommended for use with the lubricant.

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Equipment Modifications

• Check the compatibility before being converted to another type of refrigerant -- compressors, expansion valves, hot gas valves, condensor coils, evaporator coils, filter-driers, capillary tubes, pressure switches, and system piping.

• Centrifugal R-12 compressors often experience significant capacity loss as impeller design and rotational speed are exactly matched to the properties of R-12. Replacement of the impeller and/or pulley is usually required to regain lost capacity.

• Reciprocating R-12 compressors in systems operating above evaporator temperatures of 6.7 ° C usually experience equivalent performance with R-134a.

• No piping material or diameter changes are required when retrofitting with R-134a because its physical characteristics are similar to those of R-12.

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Equipment Modifications

• Some expansion valve manufacturers may recommend replacing the expansion valves because of somewhat higher operating pressures with R-134a.

• The solenoid valves, pressure switches, and hot gas valve for the R-12 system were found to operate satisfactorily with R-134a

• Filter driers were replaced with an R-134a-compatible type.

• No compressor modifications were required.

• Capacity

• At evaporator temperatures over 6.7 °C, R-134a exhibits an equivalent capacity compared with R-12.

• Some systems running at these temperatures may show slightly higher capacities with R-134a because of its higher heat of vaporization (ability of a liquid to absorb heat prior to vaporizing to a gas).

Refrigerant Retrofitting

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