Retrofitting RAC and MAC Systems

Module 5
RETROFIT RAC AND MAC SYSTEM

Unit of Competency:
Retrofitting RAC and MAC System

A Joint Project of:
DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES
Environmental Management Bureau
Philippine Ozone Desk
and
TECHNICAL EDUCATION AND SKILLS DEVELOPMENT AUTHORITY
National Institute for Technical Vocational Education and Training

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Introduction Unit Retrofit RAC and MAC sytem
Module Retrofitting RAC and MAC System

Table of Contents

How to use this module ..................................................................................................... 3
Symbols............................................................................................................................. 4
Introduction........................................................................................................................ 5

Learning Element 1: Assess Unit for Retrofit ............................................................... 7
Information Sheet No. 1: Assess Unit for Retrofit .............................................................. 9
Self-Check No. 1 ............................................................................................................... 17
Answer Key No. 1.............................................................................................................. 18

Learning Element 2: Retrofit the Unit ............................................................................ 19
Infromation Sheet No. 2: Retrofit the unit .......................................................................... 21
Operation Sheet No. 1: Retrofitting Using “Drop in” Replacement .................................... 25
Self-Check No. 2 ............................................................................................................... 27
Answer key No.2 ............................................................................................................... 28
Job Sheet No. 1: Retrofit with Alternative Refrigerant ....................................................... 29
Job Sheet No. 2: Retrofit with a “Drop in” Replacement .................................................... 30

Learning Element 3: Test Performance of Retrofitted Unit .......................................... 31
Job Sheet No. 3: Test the Operating Performance of Retrofitted Unit ............................... 33

Competency Assessment ............................................................................................... 38

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Introduction Unit Retrofit RAC and MAC sytem
Module Retrofitting RAC and MAC System

How to use this module

; Read through the learning guide carefully .It is divided into element that covers

all the skill and knowledge you need to successfully complete this module.

; Talk to your trainer and agree on how you will both organize the training of this

unit.

; Work through all the information and complete the activities in each element.

Use the multi-media and other training aids that came with the learning package.

; Most probably your trainer will also be your supervisor or manager. He/she is

there to support you and show you the correct way to do thing. Ask for help.

; Your trainer will tell you about the important things you need to consider when

you are completing activities and it is important that you listen and take notes.

; You will be given plenty of opportunity to ask questions and practice using the

Assignment Sheet or Job Sheet. Make sure you practice your new skills during
regular work shifts. This way you will improve both your speed and memory and
also your confidence.

; Talk to more experience workmates and ask for their guidance.

; Use the self-check questions at the end of each information sheet to test your

own progress.

; When you are ready, ask your trainer to watch you perform the activities outline

in the learning guide.

; As you work through the activities, ask for written feedback on your progress

check. Your trainer keeps feedback/pre-assessment reports for this reason. When
you have successfully completed each element, ask your trainer to mark on the
reports that you are ready for assessment.

; When you have completed this modules (or several module), and feel confident

that you have had sufficient practice, your trainer will arrange an appointment
with registered assessor to assess you. The results of your assessment will be
recorded in your competency Achievement Record.

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Introduction Unit Retrofit RAC and MAC sytem
Module Retrofitting RAC and MAC System

Symbols

These symbols are located in the left margin of the module. These illustrate actions
that should be taken or resource to be used at the particular stage in the module.

Learning Optional Activity
Outcome

Resources Practice

Reading Activity Self Check

Use Computer Answer Key

View Video Competency
Assessment
Listen to
Audio Tape Safety

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Introduction Unit Retrofit RAC and MAC sytem
Module Retrofitting RAC and MAC System

Introduction

Retrofitting is the replacement of the refrigerant towards alternatives. It may require
replacing specific parts of the equipment. For older refrigeration and air-conditioning systems,
it may be more cost-effective to replace rather than retrofit. In addition, new equipment will be
more energy and cost efficient.

This module covers the knowledge, skills and attitudes in retrofitting process of preparing
refrigeration and air-conditioning system for use with a replacement refrigerant and lubricant.

This also includes the selection of alternative refrigerant, lubricant components and
accessories, basic principles of retrofitting, costing your work and good servicing practices.

Learning Outcomes

On completion of this module you should be able to:

; Asses unit for retrofit
; Retrofit the unit
; Test performance of retrofitted unit.

Performance Criteria

After completion of the lessons in this unit, the student should beable to:
• Explain the advantages, disadvantages and procedures of retrofitting to

customer in layman’s terms
• Estimate the cost of retrofitting based on manufacturer’s recommendations
• Select alternative refrigerants & lubricants according to manufacturer’s

recommendations
• Select system components and accessories for retrofitting according to

application
• Perform retrofitting according to manufacturer’s recommendations
• Observe safety measures during retrofitting
• Monitor and check operating pressures, current, temperatures for

conformance with manufacturer’s operating manual
• Analyze and interpret recorded data based on manufacturer’s

recommendations
• Perform adjustment of controls and devices on pressures, current and

temperature in accordance with manufacturer’s recommendations

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Introduction Unit Retrofit RAC and MAC sytem
Module Retrofitting RAC and MAC System

Conditions

The trainee must be provided with the following:

1. Learning materials
• Module 2: Retrofitting RAC & MAC Systems
• Operators Manual

2. Equipment and Materials
• Recovery/recycling machine
• Vacuum pump
• Standard tools and devices
• Adequate supplies and materials.

3. Learning Environment
• RAC or MAC unit for servicing
• Workshop or workplace
• Training facilities

Prerequisite

Before commencing this module, you should have already completed the following
module:

• Module 1: Recover/Recycling Refrigerants
• Module : Perform Processing of RAC System
• Good Practice in Servicing R & R System

References

A. Books
• Good Practices in Refrigeration Training Manual. UNEP, December 1994
• Modern Refrigeration and Air-conditioning. Althouse/Turnquist/Brancciano.
Copyright 1992

B. Curriculum guides
• HVAC Competency Standard
• HVAC Competency-based Curriculum

C. Manuals
• Service Manual

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Learning Element 1

Assess Unit for Retrofit

Learning Outcome

On completion of this Element you should be able to:

; Explain the advantages, disadvantages of retrofitting
; Estimate the cost of retrofitting based on manufacturer’s

ecommendations

; Select alternative refrigerants & lubricants according to manufacturer’s

r ecommendations

Resources

To undertake this Element you require the following resources:
• Information Sheet 1: Assess Unit for Retrofit
• Self Check 1
• Answer Sheet 1
• Video: Back to the Future—Working Safely with Hydrocarbons

Reading Activity

Read: Learning Outcome
Study: Information Sheet 1: Assess Unit for Retrofit

Viewing Video Program

View: Ask instructor to assist you setting up the video program
• Video: Back to the Future—Working Safely with Hydrocarbons

Learning Activity 1 Unit Retrofit RAC and MAC sytem

Module Retrofitting RAC and MAC System

Optional Activity

Call Instructor: Discuss other options to attain objectives
• Ask instructor short lecture and demonstration in retrofitting.

Self Check

Do: Self-Check. 1
• Check your work with the Answer Sheet

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Unit Retrofit RAC and MAC sytem
Information Sheet 1

Module Retrofitting RAC and MAC System

Assess Unit for Retrofit Materials Capacity
Compatability Cost
I. Basic Consideration for Retrofitting
Power
1. Retrofitting is the process of preparing Requirement
a refrigeration and air conditioning
system for use with a replacement
refrigerant and lubricant. The basic idea
of retrofit is to replace the refrigerant
and refrigerating machine oil.

2. Retrofitting would appear to be a simple
matter since it involves replacing an old
refrigerant with a new one in an existing
system. However, because many other
factors are involved, it is not generally
a simple process.

3. Other economic factors must be % of Replacement Cost Open or
considered. These factors include: Hermetic
• the estimated equipment life,
• current performance, Open Only 100%
• operating requirement, and Replacement with
• the cost of equipment and Open Only 40 - 60% 60 - 80% installation cost total
equipment room modification, iSmple w/ gear Drive line retrofit
maintenance, refrigerant and 20 - 30%
electrical power. Comparison of cost Savings or impeller
of chiller upgrade is as shown.
Best Efficiency
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Information Sheet 1 Unit Retrofit RAC and MAC sytem

Module Retrofitting RAC and MAC System

4. In the refrigeration sector, often times Original CFC Possible Retrofit
ODS-based equipment can be replaced Refrigerants Refrigerant*
with transitional refrigerant such as
HCFCs, or alternative substances. The CFC - 11 HCFC - 123
most commonly used non-ozone
depleting refrigerants are HFC(which CFC - 12 HFC - 134a
have zero ODP, but contribute to global
warming) and HCs (which have zero CFC - 114 ???
ODP and zero global warming potential,
but are flammable and require specific R - 500 HFC - 134a
safety precautions).
* Approved by the U.S. Environment Protection
Agency

5. Replacement of end-of-live ODS Advantages Disadvantages
equipment may be the most economical
option taking into account the energy Alternate refrigerant May reduced
saving which may be realized by
modern technology.The advantage and is ozone friendly system efficiency
disadvantage of retrofitting are as
shown. System is can be more
overhauled expensive in case
compressor and
other components
needs replacements

Commercial Toxicity and
availavility at flamability
reasonable cost

6. A retrofit can usually performed at the
same time as a system overhaul. An
overhaul ordinarily consist of:

• Repair leaks

• Cleaning system tubing

• Charging the refrigerant and
lubricant to the proper levels,

• Adjusting controls.

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Information Sheet 1 Unit Retrofit RAC and MAC sytem

Module Retrofitting RAC and MAC System

7. Finally, the decision for retrofitting is the
end-user, but as technicians you can
advice the owner on the best option.
Guide in making your advice is shown
below.

BASIC CONSIDERATION FOR RETROFITTING

• Consider the expected energy efficiency, performance and operating costs of the
retrofitted system in addition to the direct retrofit costs.

• Consider the properties of the alternative refrigerant such as flammability, toxicity and
its global warming potential; some of these properties may require additional safety
measures.

• Consider retrofitting when major damage of the existing system requires expensive
repair work.

• Consult the system manufacturer for the appropriate alternative refrigerant/lubricant
system and the necessary replacement of system components, such as compressor,
filters, drier etc., before retrofitting.

• Consult the system manufacturer for the appropriate retrofitting procedure, which is, in
general, equipment-specific.

• Investigate the operating parameters and performance data of the existing system before
retrofitting.

• Investigate the operating parameters and performance data of the system and control
settings after completion of the retrofit.

• Re-label the retrofitted system and components to reflect the refrigerant and lubricant
change and to indicate future service needs.

• Record the retrofitting procedure in the service logbook.

Note: Observe local regulations concerning the collection, transport, storage
and. destruction of hazardous waste; contact refrigerant suppliers,
refrigeration associations or appropriate government institutions.

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Unit Retrofit RAC and MAC sytem
Information Sheet 1

Module Retrofitting RAC and MAC System

II. Retrofit Factor and Costing

1. The decision to replace or convert Cost Vs. Efficiency
existing equipment should be made
only after carefully considering the total
costs of both scenarios. To minimize the
cost, if timing permits, it is best to
undertake a retrofit operation around a
major maintenance period. Many of the
components would normally be replace
during a major maintenance overhaul.

Note: Retrofits when compressor
has failed and will be
replaced is much more cost
effective

2. Many air-conditioning and refrigeration
system running on CFC will be
retrofitted to ozone friendly HFCs (i.e.
134a etc.) refrigerants. This will require
flushing the mineral oil from the
systems and replacing it with synthetic
ester lubricants. To be able to perform
such a task the service contractor
needs to be well aware of the retrofit
performance and what to consider.

3. Several factors should be consider
when approaching a refrigerant retrofit:

• Alternative refrigerant cost.

• Availability of alternative refrigerants
in the present and the future.

• Expected life of existing equipment.

• Refrigerant leak history of
equipment.

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Unit Retrofit RAC and MAC sytem
Information Sheet 1

Module Retrofitting RAC and MAC System

4. As a service technician, it is your work
to advice equipment owner the best
way to minimized cost, and at the same
time maximizes the efficiency of the
equipment. Example on costing is
shown below:

Example of costing retrofit

No. Measure Unit Cost/Unit Hours Cost/Hour Cost

1 Assessment 1 100 100

No Recovery to change oil -
3 Change oil
3x1L 800 3x2 100 3000

1 Recovery to change refrigerant 2 100 200

1 New refrigerant 3 kg 300 1 100 1000

1 New filter 1 pc. 500 500
1 Commissioning 1 100 100

Total cost ot retrofit 4900

III. Alternative Refrigerants and
Lubrication

1. In selecting ozone-compatible
alternatives for CFCs, two molecular
concepts are to be used:
• Eliminate (or at least minimize) C-
Cl bonds, and
• Include C-H bonds

This is in addition to maintaining
the desirable physical and physiological
properties already ascribed to the CFCs.

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Information Sheet 1 Unit Retrofit RAC and MAC sytem

Module Retrofitting RAC and MAC System

2. With these criteria set forth, the major
CFCs producers, such as DuPont,
Solvay, and ICI, searched the tables of
known fluorocarbons in an attempt to
match these properties. From these
tables, which are extensive only a few
compounds approximate the physical
properties of the existing CFCs.The
following table identifies these
compounds:

List of Alternative Refrigerants

Replacement Alternative ODP Main Application
for Refrigerant

R - 11 R - 123 0.02 Water chillers
R - 134a 0
R - 12 Domestic and Commercial
Refrigeration(medium temperature),
fixed and vehicle air-con, water chiller

R - 409A 0.05 Commercial and transport refrigeration

R - 502 R - 404A 0 Commercial and transport refrigeration
R - 22 R - 408A 0.026 Retrofit of existing R - 502 systems
R - 500
R - 22 0.055 Air-conditioning

R - 407C 0 Stationary air-conditioning

R - 410A 0 Stationary air-conditioning

R - 404A 0 Refrigeration
Blends
Commercial and Industrial

R - 114 HCFC 124 Chiller application, marine

R - 115 HFC 125 0 Low temperature

R - 12/ R - 22 Hydrocarbons 0 Domestic/Air-conditioners

R - 114 HCFC - 142b Refrigeration

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Unit Retrofit RAC and MAC sytem
Information Sheet 1

Module Retrofitting RAC and MAC System

3. The factors that have to be considered in choosing an alternative refrigerant are:
• The refrigerant’s atmospheric lifetime
• The ozone depletion potential (ODP)
• The total equivalent warming index (TEWI) in the intended application
• The refrigerant toxicity and flammability
• The pressure under which the refrigerant operates
• Its heat transfer characteristics
• Its compatibility with materials used in the system
• Miscibility and compatibility with lubricants

IV. Oils for Alternative Refrigerants

1. An important consideration in the development of hydro chlorofluorocarbon (HCFCs)
and hydro fluorocarbons (HFCs) as alternative refrigerants is the testing of oils for
solubility, stability, lubricity with the refrigerant, and compatibility with materials of
construction. Testing will determine which lubricants can be used in current systems
and what changes are required.

2. In general the ternary blends and HCFCs can be used with oils that are commercially
available; however, some development work may be required to optimized performance.
Applications with HFCs require the development of new oils. The desirable properties
for developmental use are:
• Acceptable solubility with the refrigerant (ideally, single phase over a broad
temperature range);
• Acceptable lubricity;
• Good thermal stability for the refrigerant/lubricant combination;
• Acceptable compatibility with system materials (elastomers, metals and plastics);
• Low toxicity; and
• Commercial availability at a reasonable cost.

3. Listed below are the refrigeration lubricating oils and their characteristics:
Mineral Oil (MO)
• Designed for and miscible in CFC/HCFC
• Very soluble in HC (higher viscosity/superheat can be required
Alkylbenzene (AB)
• Designed for and miscible in CFC/HCFC
• Low viscosity AB is also used in rotary compressors for R-407C
Polyol ester oil (POE)
• Designed for HFC compatibility
• Soluble in CFC/HCFC/HFC/HC
• High solubility in CFC/HCFC/HC must be considered

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Unit Retrofit RAC and MAC sytem
Information Sheet 1

Module Retrofitting RAC and MAC System
Polyalkylene glycol (PAG)
• Designed for HFC compatibility
• Not considered suitable with CFC/HCFC

HFC Oils
Polyol esters (POE) and Poly alkylene Glycol (PAG)

PAG oils are developed for Mobile air conditioning (MAC).
• These oils are extremely sensitive to humidity and will absorb moisture from air if

exposed to ambient
• Should always be kept in well-sealed cans
• PAG oil in cans that have opened and not protected with dry nitrogen should not be

used in system
• Humidity will drastically reduce stability and reduce lifetime of system
• Careful evacuation and use of nitrogen are essential for long term reliability

POE oils are developed for stationary refrigeration and air conditioning (RAC)
systems but are also used by some auto manufacturers for retrofit as they are more tolerant
to contaminations than PAG.

• POE oils are sensitive to humidity and will absorb moisture from ambient air if
exposed

• Humidity will drastically reduce stability and reduce lifetime of system
• Careful evacuation and use of nitrogen are essential for long term reliability
Low viscosity Alkylene Benzene (AB) are used in rotaries for R407C and R410A.

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Self Check No. 1 Unit Retrofit RAC and MAC sytem
Module Retrofitting RAC and MAC System

QUESTIONS Satisfactory
The student/trainee should answer all the following questions Response

YES NO

1. What is the importance of retrofitting?

2. What are the advantages and disadvantages of retrofitting?

3. what lubricants are suited for HFC refrigerants?

4. What are the alternative refrigerants for R - 12?

5. In selecting ozone-compatible alternatives for CFCs, two molecular
concepts are to be used. What are they?

6. What are the factors to be consider when approaching refrigerant
retrofit?

7. Define retrofitting

The students underpinning knowledge was:

Satisfactory Not Satisfactory
Feedback to student/trainee:

Candidate Signature: Date:
Instructor Signature: Date:

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Answe key No. 1 Unit Retrofit RAC and MAC sytem
Module Retrofitting RAC and MAC System

1. The unit will be ozone-friendly.

2. A. Advantages

a. alternative refrigerant is ozone friendly

b. system is overhauled

c. commercial availability at reasonable cost

B. Disadvantages

a. may reduced system efficiency

b. can be more expensive in case compressor and other components

needs replacements

c. Toxicity and flammability (in case of hydrocarbons)

3. Polyolester oil, Polyalkylene oil

4. R – 134a, R- 409A, Hydrocarbon

5. a. Eliminate (or at least, minimize) C-Cl bonds,
b. Include C-H bonds

6. 1. Alternative refrigerant cost
2. Availability of alternative refrigerant, in the present and future.
3. Expected life of existing equipment.
4. Refrigerant leak history of equipment.

7. Retrofitting is the process of preparing a refrigeration and air conditioning
system for use with a replacement refrigerant and lubricant. The basic idea
of retrofit is to replace the refrigerant and refrigerating machine oil.

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Learning Element 2

Retrofit the Unit

Learning Outcome

On completion of this Element you should be able to:

; Select alternative refrigerant and lubricant for retrofitting

according to application
; Observe safety measures when retrofitting

; Perform retrofitting according to manufacturer’s

recommendations

Resources

To undertake this Element you require the following resources:

• Information Sheet 2: Retrofit the Unit
• Self Check 2
• Answer Sheet 2
• Video: Good Practice in Refrigeration
• Operation Sheet 1: Retrofitting Using “Drop in” Replacement
• Job Sheet 1: Retrofit with Alternative Refrigerant
• Job Sheet 2: Retrofit with a “Drop in” Replacement

Reading Activity

Read: Learning Outcome
Study: Information Sheet 2: Retrofit the Unit

Learning Activity 2 Unit Retrofit RAC and MAC sytem

Module Retrofitting RAC and MAC System

Viewing Video Program

View: Ask instructor to assist you setting up the video program
ƒ Video: Good Practice in Refrigeration

Optional Activity

Read: Operation Sheet 1: Retrofitting Using “Drop in” Replacement
Call Instructor: Discuss other options to attain objectives

ƒ Ask instructor demonstration of retrofitting works.

Self Check

Do: Self-Check. 2
ƒ Check your work with the Answer Sheet

Practice Activity

Practice: Job Sheet 1 Retrofit with Alternative Refrigerant
Job Sheet 2 Retrofit with a “Drop in” Replacement

ƒ Ask permission from instructor
ƒ Prepare equipment, tools and materials
ƒ Observe safety practices
ƒ Maintain cleanliness

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Information Sheet 2 Unit Retrofit RAC and MAC sytem

Module Retrofitting RAC and MAC System

Retrofit the Unit

I. Retrofit Systems

1. After all refrigerant decisions have been made, the implementation of a refrigerant
retrofit program is best accomplished in a methodical, organized manner. Every system
has unique operating conditions. It is important to remember that all current practices
for refrigeration system services still apply with the alternative refrigerants. The basic
refrigeration cycle still applies, and changes that accompany the alternative refrigerants
involve additional service practices that must be followed. The accompanying retrofit
checklist may be used as a guide during the preliminary assessment of an existing
system. Remember that a successful retrofit begins with a thorough analysis of the
existing system. This is done before any retrofit procedures.

2. Generally, a successful retrofit should be prefaced by the following steps:
• Assess existing equipment and examine the system for potential problem areas
(low point, poor piping, etc.)
• Determine the service and operational history of the equipment.
• Carefully record all information regarding the existing system components (i.e.,
compressor, valves, heat transfer surfaces, piping, etc.).
• Establish existing system operating conditions (pressures, temperatures, amperage,
etc.) to determine the baseline operation. This step is essential in determining whether
or not the existing system is actually producing the desired refrigeration effect.
• Cross-reference all existing components to the intended alternative refrigerant. Many
components are likely to be acceptable; however, some system components may
need to be changed.
• Material compatibility is best determined by the OEM. Be sure to consult the OEM
recommendation for retrofits—this is especially important for older systems.
• Once the equipment selections have been made and all preliminary investigation is
complete, a thorough leak-check of the system should be performed. Remember
that the genesis of this CFC problem is in a large part of result of excessive leakage.
• Further, the leak characteristics of some of the alternatives mandate the need for
“very tight” systems.
• After all preliminary work is complete, the retrofit procedure

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Unit Retrofit RAC and MAC sytem
Information Sheet 2

Module Retrofitting RAC and MAC System

II. Safety requirements:

Low- and high-pressure refrigerants need to be handled as compressed gases, and
refrigerant containers are pressure vessels, which require particular safety considerations.

Specific Safety Practices:
DOs:
• Use specific colors for containers for different refrigerant types (see document 14 in
Annex G).
• Comply with mandatory safety precautions for systems retrofitted with alternative
refrigerants, such as hydrocarbons or ammonia, which might be flammable or toxic
(these are beyond the scope of this Guidebook).
• Properly label all cylinders using country-approved hazard labels where applicable.
• Use proper protective caps over refrigerant valves to prevent damage to the valve on
top of the cylinder.
• Recover refrigerant prior to servicing.
• Use nitrogen in cleaning refrigeration piping.
• Use non-CFC as gas tracer.
• horoughly leak test system before changing.
DON’Ts
• Do not substitute refrigerant with drop-in alternatives without consulting the system
manufacturer.
• Do not exceed the manufacturer’s recommended pressure or system strength test
pressure when leak testing.
• Do not overfill refrigerant containers, tanks, drums, recovery units, receivers, etc.
• Do not refill disposable cylinders.
• Do not use an open flame on any refrigeration system that has not been properly
evacuated for servicing.
• Do not service refrigeration systems unless wearing protective clothing, including goggles
and gloves.
• Do not attempt to service equipment unless fully trained in the safe handling of
refrigerants.
• Do not work with refrigerants in a confined space lacking ventilation.
• Do not blow off a piping system with air or oxygen to remove welding, brazing or cutting
debris, because this may cause contamination and the risk of explosion; only dry nitrogen
should be used for this task.
• Do not pressurize refrigeration or piping systems with air or oxygen.
• Do not use CFC as gas tracer.

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Unit Retrofit RAC and MAC sytem
Information Sheet 2

Module Retrofitting RAC and MAC System

III. Retrofitting Procedure

1. Ensure that the system is leak tight
2. Recover the refrigerant into a clean cylinder.
3. Drain the mineral oil from the system and replace it with correct quantity of

appropriate polyolester lubricant.
4. Recharge the system with the previously recovered refrigerant.
5. Run the system for long enough to “flush” the system mineral oil residues.
6. Stop system and recover the CFC refrigerant again into the clean recovery cylinder.
7. Drain the oil mixture and recharge the system with fresh polyolester lubricant.
8. Recharge the system with recovered CFC refrigerant.
9. Run the system for long enough to “flush” the system mineral oil residues.
10. Stop system and recover the CFC refrigerant again into the clean recovery cylinder.
11. Drain the polyolester mineral oil mixture and test it with an appropriate test kit. The

target mineral oil/polyolester lubricant concentration is 5% mineral oil 95% polyolester
lubricant. (Preferably less than 5% mineral oil.)
12. If the mineral oil residue is higher than 5% then repeat the flushing procedure until
its lower.
13. Once the mineral oil concentration is below 5% then recharge the system with fresh
polyolester, change the drier, test for leak, and if system is free from leak, evacuate
the system.
14. Now charge the system with alternative refrigerant in accordance with the
manufacturers instructions/recommendation.
15. Run the system and make any adjustment as required.
16. Thoroughly leak test system and ensure that all valve caps are in place and tight.

Note: Although HFC refrigerant will give acceptable performance in the CFC/
HCFC system, some of the materials may not be compatible and this can
lead to component failure and leakage. It is advisable to consult with the
manufacturer before changing system refrigerant.

II. Alternative refrigerants

Replacement refrigerants are gradually becoming available, but the earliest ones are
either blends of HCFC-22, and thus have a limited life expectancy, or consist of blends of new
“ozone friendly” (non-ODS) refrigerants that are undergoing the the last stages of toxicity
testing. However, several blends are now available, that are based upon HFCs only, such as
R-404 and R-410.

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Unit Retrofit RAC and MAC sytem
Information Sheet 2

Module Retrofitting RAC and MAC System
There are three categories into which replacement fluids can fall. These are:

• DROP-INS — fluids that can be substituted into an existing system without any
work being required apart from very minor servicing such as the replacement of a
refrigerant filter dryer.

• RETROBITTABLE FLUID —fluids that can be substituted into an existing plant but
only after certain changes are made, such as substitution of new type of lubricating
oil or a modification of compressor speed.

• NON-RETROFITTABLE FLUID — fluids that cannot be used in existing equipment
even with major modifications, because of different operating pressures materials
incompatibility and other potential problems.

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Unit Retrofit RAC and MAC sytem
Operation Sheet 1

Module Retrofitting RAC and MAC System

Retrofitting Using “Drop in” Replacement

Another type of retrofitting is the use of “drop in” replacements. “Drop in” replacements
need no change of lubricants and other accessories of the unit except for the filter drier which
is mandatory practice in servicing.

There are number of “drop in” replacements available now. It must be noted that if you
will use “hydrocarbons” drop in replacement, outmost care must be taken into consideration.
A technician should possess a special training when dealing with hydrocarbon because of its
flammability and explosiveness.
Procedure to retrofit a system with “drop in” replacement

1. Check system for leaks
2. Recover CFC refrigerant into appropriate containers and label it.
3. Record weight of recovered CFC
4. Change liquid line drier
5. Evacuate system to 500 microns (If you will use hydrocarbons, all spark producing

mechanical and electrical components must be replaced, repositioned or enclosed)
6. Charge the replacement “drop in” into system in accordance with manufacturer’s

instruction (i.e. for weight in liquid phase from the cylinder)
7. Start system and observe the operation of the unit, make adjustment if necessary to

expansion valve, Hi switch pressure and Lo pressure switch cut outs etc.
8. Leak test the system
9. Label the system with the new refrigerant type and remove the old labels to prevent

confusion in the future.
Note: Wear personal protective equipment and work in a well ventilated area.

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Unit Retrofit RAC and MAC sytem
Operation Sheet 1

Module Retrofitting RAC and MAC System

The general procedure used to retrofit a system from CFC to HFC refrigerant is as
follows:
1. Check the system for leaks
2. Recover/recycle the CFC refrigerant into a clean cylinder
3. Drain the mineral oil from the system and replace it with the correct quantity of appropriate

polyolester lubricant.
4. Recharge the system with the previously recovered CFC refrigerant
5. Run the system for long enough to flush the system mineral oil residues.
6. Stop system and recover the CFC refrigerant again into the clean recovery cylinder.
7. Drain the oil mixture and recharge the system with fresh polyolester lubricant.
8. Recharge the system with recovered CFC refrigerant.
9. Run the system for long enough to flush the system mineral oil residues.
10. Stop system and recover the CFC refrigerant again into the clean recovery cylinder.
11. Drain the polyolester/mineral oil mixture and test it with appropriate test kit or

refractometer. The target mineral oil/polyolester lubricant concentration is 5% mineral
oil 95% polyolester lubricant. (Preferably less than 5% mineral oil).
12. If the mineral oil residue is higher than 5% then repeat the flushing procedure until it is
lower.
13. Once the mineral oil concentration is below 5% then, recharge system with fresh
polyolester lubricant, change drier and evacuate the system thoroughly.
14. Now charge system with HFC refrigerant in accordance with the manufacturers
instruction.
15. Run system and make any adjustment as required.
16. Thoroughly leak test system and ensure that all valve caps are in place and tight.

NOTE: Although HFC refrigerant will give acceptable performance in CFC/HFC
system, some of the materials may not be compatible and this can lead to
component failure and leakage. It is advisable to consent with the manufacturer
before changing system refrigerant. Wear personal protective equipment.

26

Self Check No. 2 Unit Retrofit RAC and MAC sytem
Module Retrofitting RAC and MAC System

QUESTIONS Satisfactory
The student/trainee should answer all the following questions Response
1. How do you apply safety measure in retrofitting the system?
2. What precautions must you take in handling refrigerants? YES NO

3. What would you do if something in the system malfunction? What
action should you take?

4. Whay should we not leave lubricant uncovered?

5. What are the three categories in which replacement fluids can fall?

6. Give the standing pressure and temperature of the following

refrigerant.

Refrigerant Pressure Tempreature

a) R - 12

b) R - 22

c) R - 134a

The students underpinning knowledge was:

Satisfactory Not Satisfactory
Feedback to student/trainee:

Candidate Signature: Date:
Instructor Signature: Date:

27

Unit Retrofit RAC and MAC sytem
Answer Key No. 2

Module Retrofitting RAC and MAC System

1. a. always wear protective clothing
a. always work in a ventilated area
b. never apply heat to a system with pressure in it.
c. Never use air or oxygen in cleaning the system.

2. a. always wear gloves and goggles in handling refrigerants
b. always cover the valve spindle of refrigerant cylinder
c. always secure refrigerant cylinder.
d. Do not vent refrigerant in the atmosphere

3. Stop retrofitting. Troubleshoot the unit. Recover refrigerant , if necessary.

4. It will absorb moisture from the atmosphere.
5. a. drop-ins

b. retrofittable fluid
c. non-retrofittable fluid
6. The standing pressure of the following refrigerant:

Refrigerant Pressure Temperature
a) R - 12
b) R - 22
c) R - 134a

28

Job Sheet No. 1 Unit Retrofit RAC and MAC sytem
Module Retrofitting RAC and MAC System

Retrofit with Alternative Refrigerant Observation
Checklist
Equipment:
• Gauge manifold set YES NO N/A
• Vacuum pump of adequate size
• Alternative refrigerant
• Alternative lubricant
• Recovery and recycling machine
• Leak testing device
• Nitrogen
• Oxyacetylene set

Procedure

1. Recover refrigerant

2. Drain oil

3. Perform flashing of mineral oil

4. Change unit with alternative refrigerant and oil

5. Label the unit with new refrigerant type

6. Safety measure are applied

7. Perform housekeeping

29

Job Sheet No. 2 Unit Retrofit RAC and MAC sytem
Module Retrofitting RAC and MAC System

Retrofit with a “Drop in” Replacement

Equipment:
• Gauge manifold set
• Vacuum pump of adequate size (spark free)
• Soap suds solution
• Valve key and suitable spanners/wrenches
• Appropriate hydrocarbons.

Procedure Observation
1. Pressure test system with nitrogen Checklist

YES NO N/A

2. Soap (bubble) test joints-repair leak if appropriate

3.Release nitrogen safely

4. Evacuate and dehydrate system - prove vaccum tight

5. Retrofit with a "drop-in" replacement

6. Record operating conditions

Note: This should only be given to those with evidence of knowledge, skills and
attitude in dealing with hydrocarbons.

30

Learning Element 3
Test Performance of Retrofitted Unit

Learning Outcome

On completion of this Element you should be able to:

; Monitor and check operating pressures, current, temperatures

for conformance with manufacturer’s operating manual

; Analyze and interpret recorded data based on manufacturer’s

recommendations

; Perform adjustment of controls and devices on pressures,

current and temperature in accordance with
manufacturer’s r ecommendations

Resources

To undertake this Element you require the following resources:
• Information Sheet 3: Test Performance of Retrofit Unit
• Job Sheet 3: Test the Operating Performance of Retrofitted Unit

Reading Activity

Read: Learning Outcome
Study: Information Sheet 3: Test Performance of Retrofitted Unit

Learning Acitivity 3 Unit Retrofit RAC and MAC sytem

Module Retrofitting RAC and MAC System

Optional Activity

Call Instructor: Discuss other options to attain objectives
Ask instructor for demonstration testing a retrofit unit.

Practice Activity

Practice: Job Sheet: 3 Test the Operating Performance of Retrofitted Unit
• Ask permission from instructor
• Prepare equipment, tools and materials
• Observe safety practices
• Maintain cleanliness

Competency Assessment

Assessment: When you feel confident you can perform all the elements in
this module submit for assessment.
• Call Instructor or Assessor
• Study Assessment Guide
• See to it that all the equipment, tools and materials are available.
• Perform the activities asked in the assessment guide
• Let instructor check your work.

32

Job Sheet 3 Unit Retrofit RAC and MAC sytem
Module Retrofitting RAC and MAC System

Test the Operating Performance of Retrofitted Unit

Equipment: Retrofitted Unit

Instrument: Thermometer, System analyzer, Clamp Tester

Procedure Ob s er b atio n
Checklist
Test the operating performance of retrofitted unit using the following
steps YES NO N/A

1. prepare the unit and instruments required for testing retrofitted unit
such as; system analyzer, clamp-on ammeter and retrofitted.

2. Connect the unit to the analyzer.

3. Clamp the ammeter in one of the two lines of the power supply
chord.

4. Run the retrofitted unit for thirty minutes.

5. Take reading of:
perature ______psi/kpa ______ oC/oF

b. Discharge pressure/temperature ______ psi/kpa _____ oC/oF
c. Running current ________ amperes

5. Analyze and interpret the above readings based on the
recommended operating pressure, temperature and current. Make
necessary adjustments if needed until normal operating pressure is
attained.

6. For retrofitted unit (time tested/time of operation)
Time Started ___________
Time Ended ___________
Total Time ____________

Note: See specifications recommended by the manufacturer.

7. Inspection form fully accomplished.

8. Make recommendations for furher maintenance action.

33

Job Sheet 3 Unit Retrofit RAC and MAC sytem
Module Retrofitting RAC and MAC System

Forms and attachments
Comparative Data between the system before and after retrofitting

BEFORE AFTER * RECOMMENDED REMARKS
RETROFITTING RETROFITTING VALUE

Suction Pressure (RETROFITTED
(PSI/Kpa) UNITS)

Suction
Temperature
(? F/? C)

Discharge
Pressure
(PSI/Kpa)

Running
Temperature
(? F/? C)

Running Current
(AMP)

Cabinet
Temperature
(ºF/ºC)

Type of
Refrigerant

Superheat (ºF/ºC)

34

Job Sheet 3 Unit Retrofit RAC and MAC sytem
Module Retrofitting RAC and MAC System

Cabinet temperatures are fairly standard. The table below shows the recommended
fixtures (cabinet) temperatures for some common fixtures (cabinets).

Fixture (Cabinet) Temp oF Temp. oC
Back Bar 37 - 40 3-4
Beverage Cooler 37 - 40 3-4
Beverage Precooler 35 - 40 2-4
Candy Case (Display) 60 - 65
Candy Case (Storage0 58 - 65 16 - 18
Dairy Display Case 36 - 39 15 - 18
Double Display Case 36 - 39
Delicatessen Case 36 - 40 2-3
Dough Retarding Refrigerator 34 - 38 2-3
Florist Display Refrigerator 40 - 50 2-4
Florist Storage Case 38 - 45 1-3
Frozen Food Cabinet (Closed) -10 to -5 4 - 10
Frozen Food Cabinet (Open) -7 to -2 3-7
Grocery Refrigerator 35 - 40 -23 to - 21
Retail Market Cooler 34 - 39 -22 to - 19
Pastry Display Case 45 - 50 2-4
Restaurant Service Refrigerator 36 - 40 1-3
Restaurant Storage Cooling 35 - 39 7 - 10
Top Display Case (Closed) 35 - 42 2-4
Vegetable Display Refrigerator (Closed) 38 - 42 2-3
Vegetable Display Refrigerator (Open) 38 - 42 2-6
3-6
3-6

35

Job Sheet 3 Unit Retrofit RAC and MAC sytem
Module Retrofitting RAC and MAC System

Recommended fixture (Cabinet) temperature.

Application Temp oF Temp. oC

Service 34 - 38 1-3
Meats 30 - 34 -1 to 1
Bananas 60 - 65 16 - 18
Fresh Meats 28 - 32 -2 to 0
Aging Room 30 - 34 -1 to 1
Chill Room 35 - 39 2-3
Curing Room 32 - 36 0-2
Freezer Room
Poultry -15 -26
Vegetables, Fresh 30 - 34 -1 to 1
Ice Cream Hardening 36 - 42 2-6
Ice Cream Storage
Plants and Flowers - 25 - 32
Fur Storage -20 to -10 -29 to - 23
Locker Room
38 - 50 3 - 10
33 - 37 0-3
-5 to 0 -21 to -18

Recommended temperatures for various refrigeration applications.

• Normally, the refrigerant will be 10oF (6oC) colder than the evaporator temperature
when the unit is running. The refrigerant and evaporator will become the same
temperature during the off cycle.

• The evaporator surface temperature depends on its size and the rate at which heat is
being removed from the fixture.

• The temperature of a typical frosting type evaporator (domestic type) will vary from 0
OF to 25 OF (-18 OC to 4 OC), and the refrigerant temperature will be about 10 OF (6 OC)
lower than this or in range of -10 OF to 15 OF (-23 OC to -9 OC) while the unit is running.

Refrigerator Temperature

• The low side pressure in a refrigerating system determines the temperature in the
evaporator.

• One must first determine the temperature that is wanted in the cabinet or fixture, then
adjust the motor control until this temperature is maintained. However, there are many
cases where both a certain evaporator temperature and a cabinet temperature
relationship should exist.

36

Job Sheet 3 Unit Retrofit RAC and MAC sytem
Module Retrofitting RAC and MAC System

Cross Reference Table for Single Phase, 220 Volts Compressor Motor

HP NLA FLA LRA
1/20 0.1 0.3 1.0
1/12 0.2 0.6 4.0
1/10 0.6 0.9 7.0
1/8 0.8 1.2 10.0
1/6 1.4 1.8 13.0
1/5 1.8 2.0 15.0
1/4 2.0 2.5 17.4
1/2 2.8 3.0 21.6
3/4 2.0 3.1 18.0
¾ 6.8 34.0
1 3.2 6.4 38.0
1¼ 3.3 7.6 45.6
1½ 5.1 10.20 61.2
1¾ 6.0 12.0 72.0
7.5 15.0 90.0
2
2½

Legend:

HP - Horsepower
NLA - No Load Amperage
FLA - Full Load Amperage
LRA - Lack Rotor Amperage

37

Competency Unit Retrofit RAC and MAC sytem
Assessment Module Retrofitting RAC and MAC System

Name Date

Competency: Retrofit Refrigeration and Air Conditioning Test Attempt
Systems 1st 2nd 3rd

r rr

Directions: LEVEL OVERALL EVALUATION
ACHIEVED PERFORMANCE LEVEL
1. Ask instructor to assess your
competencies of the critical 4 Can perform the skill without supervision and with adaptability
performance criteeria listed to problem situations
below.
3 Can perform the skills satisfactorily without assistance or
2. You will be evaluated using supervision
the guide on the other side
2 Can perform this skill satisfactorily with some assistance and
supervision

1 Can perform parts of this skill satisfactorily with full assistance

0 Cannot perform this skill
INSTRUCTOR WILL INITIAL LEVEL ACHIEVED

PERFORMANCE STANDARDS PEFORMANCE
LEVEL
1. Assess Unit to be Retrofitted
YES NO N/A
1.a Estimate cost of retrofitting based on manufacturer's
recommendation

1.a.1 Select alternative refrigerants and lubricants
according to manufacturer's recommendation.

2. Perform Retrofitting Process

2.a Select system components and accessories for retrofitting
according to application;

2.b Perform retrofitting according to manufacturer's
recommendation; and

2.c Observe safety measures during retrofitting.

3. Monitor and check operating pressures, current

3.a Temperatures for conformance with manufacturer's
operating manual
3.a.1 Analyze and interpret recorded data based on
manufacturer's recommendations
3.a.2 Perform adjustment of controls and devices on
pressures, current and temperature in accordance
with manufacturer's standards

38

A Joint Project of:
DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES
Environmental Management Bureau
Philippine Ozone Desk
and
TECHNICAL EDUCATION AND SKILLS DEVELOPMENT AUTHORITY
National Institute for Technical Vocational Education and Training

Contracting Institution:

Department of Environment and Natural Resources
Environmental Management Bureau
Philippine Ozone Desk

Implementing Institution:

Technical Education and Skills Development Authority
National Institute for Technical Vocational Education and Training

© TESDA, 2004

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or in a workplace where the training is being conducted. This permission does not extend to
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made, nor making copies for hire or resale to third parties. For permission outside these
guidelines, apply in writing to NITVET.

The views expressed in this version of the work do not necessary represent the views
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