Service and Maintain Domestic Refrigeration and Air-Conditioning (DomRAC) Unit

COMPETENCY BASED LEARNING MATERIAL

Sector:

HEATING AND VENTILATING AIR CONDITIONING (HVAC)

Qualification:

Refrigeration and Air Conditioning Servicing(DomRAC) NC II

Unit of Competency:

Service and Maintain Domestic Refrigeration and Air-Conditioning
(DomRAC) Unit

Module Title:Servicing and Maintaining Domestic Refrigeration

Provincial Training Center –Tarlac ( PTC-Tarlac)
San Isidro, Tarlac City

HOW TO USE THIS COMPETENCY BASED LEARNING MATERIAL

Welcome to the module in Servicing and Maintaining Domestic Refrigeration
and Air-Conditioning (DomRAC) Unit. This module contains training materials and
activities for you to complete.

The unit of competency “Servicing and Maintaining Domestic Refrigeration and
Air-Conditioning (DomRAC) Unit " contains knowledge, skills and attitudes required
for a Refrigeration and Air Conditioning Servicing (DomRAC) NC II course. It is
one of the specialized modules at National Certificate II (NC II) level.

You are required to go through a series of learning activities in order to complete
each learning outcome of the module. In each learning outcome are Information
Sheets and Resources Sheets (Reference Materials for further reading to help you
better understand the required activities). Follow these activities on your own and
answer the self-check at the end of each learning outcome. You may remove a blank
answer sheet at the end of each module (or get one from your facilitator/trainer) to
write your answers for each self-check. If you have questions, don’t hesitate to ask
your facilitator for assistance.

Recognition of Prior Learning (RPL)

You may already have some or most of the knowledge and skills covered in this
learner's guide because you have:

been working for some time
already completed training in this area.

If you can demonstrate to your trainer that you are competent in a particular skill
or skills, talk to him/her about having them formally recognized so you don't have to
do the same training again. If you have a qualification or Certificate of Competency
from previous trainings, show it to your trainer. If the skills you acquired are still
current and relevant to the unit/s of competency they may become part of the
evidence you can present for RPL. If you are not sure about the currency of your
skills, discuss this with your trainer.

This module was prepared to help you achieve the required competency, in
Refrigeration and Air Conditioning Servicing (DomRAC) NC II. This will be the
source of information for you to acquire knowledge and skills in this particular trade
independently and at your own pace, with minimum supervision or help from your
instructor.

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 Talk to your trainer and agree on how you will both organize the Training of this
unit. Read through the module carefully. It is divided into sections, which cover all
the skills, and knowledge you need to successfully complete this module.

 Work through all the information and complete the activities in each section. Read
information sheets and complete the self-check. Suggested references are included
to supplement the materials provided in this module.

 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 things.

 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 on the job.
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 section to test your own progress.

 When you are ready, ask your trainer to watch you perform the activities outlined
in this module.

 As you work through the activities, ask for written feedback on your progress. 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 module (or several modules), 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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NATIONAL CERTIFICATE LEVEL II

QUALIFICATION LEVEL

COMPETENCY-BASED LEARNING MATERIALS

NO CORE COMPETENCIES MODULE TITLE CODE

Install domestic Installing Domestic

1 refrigeration and air- Refrigeration and Air- HVC723337
conditioning (DomRAC)
Conditioning (DomRAC)

units Units

Service and maintain Servicing and

domestic Maintaining Domestic

2 refrigeration and air- Refrigeration and Air- HVC723338

conditioning Conditioning

(DomRAC) units (DomRAC) Units

Trouble shoot domestic Trouble shooting

3 refrigeration and air- Domestic Refrigeration HVC723339
conditioning (DomRAC) and Air-Conditioning

units (DomRAC) Units

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MODULE CONTENT

UNIT OF COMPETENCY:Service and Maintain Domestic Refrigeration and
Air-Conditioning (DomRAC) Units

MODULE TITLE: Servicing and Maintaining Domestic Refrigeration

and Air-Conditioning (DomRAC) Units

MODULE DESCRIPTOR:

This unit covers the knowledge, skills and attitudes in servicing and maintaining
domestic refrigeration and air-conditioning units. Specifically it includes cleaning
and replacing air filters, servicing evaporator/ condenser, maintaining fan motor
assembly, servicing electrical power and control circuits as well as accomplishing
service and maintenance report.

NOMINAL DURATION: 40 Hours

LEARNING OUTCOMES:

At the end of this module you must be able to:

- Clean / replace air filter
- Service evaportor and condenser
- Maintain fan motor assembly
- Service electrical power and control circuit
- Maintain refrigeration system

ASSESSMENT CRITERIA:

1. Parts / components of the window type air-conditioning are identified and
removed in accordance with SOPs.

2. Parts / components of the window type air-conditioning are clean in
accordance with SOPs.

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3. Air filter is checked if there is a damage in line with standard operating
procedures.

4. Filter is replaced in accordance with filter specification.

5. High pressure washer is used in cleaning evaporator /condensing coil with
recommended pressure for cleaning.

6. Proper tools are selected in dismantling the evaporator / condensing unit.

7. Cleaning agent or non-corrosive chemical is used in cleaning and
maintaining eapoarator / condensing coil, plates and fins.

8. Evaporator / condenser coils fins are repaired if damage and replaced
In accordance with service procedures.

9. Effective communication with others is used to ensure safe and
effective work operations.

10. Fan motor shaft blade is checked in line with normal operation and
Rotation

11. Fan motor is lubricated with no spillage in line with maintenance
procedures.

12. Parts / components are cleaned in accordance with standard
procedures.

13. Safety procedures are demonstrated according to work site
operations.

14. Appropriate processes, tools and equipment are selected and used to
carry out tasks.

15. Service and maintenance procedures are followed in accordance with
the manufacturers.

16. All parts of the refrigerant circuit are checked / inspected as per
manufacturer’s manual specification.

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17. Refrigerant circuit condition is accurately diagnosed, repaired and
reported in line with service and repair procedures.

18. Effective communication with others is used to ensure safe and
effective work operations.

19. Worksite is cleaned and kept in safe state in line with work
instructions.

20. Correct instrument is used in checking power supply and diagnosing
electrical control.

21. All controls / wiring are checked and inspected as per schematic
diagram in line with SOP.

22. Loose connections / wiring and defects are accurately diagnosed,
repaired and reported in line with SOP.

23. Effective communication with others is used to ensure safe and
effective work operations.

Qualification Levels:

Trainees Qualifications:

- At leastHigh School Graduate
- 16 years of age
- With good moral character
- Has passed the aptitude test given by the Center
- Physically and mentally fit for training
- Has no criminal records
- Can communicate in oral and written form
- Can perform basic mathematical computation

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LEARNING OUTCOME SUMMARY

Learning Outcome #1: CLEAN AND REPLACED AIR FILTER

CONTENTS:

 Types and classification of air filter used in WAC
 Effects of restricted air flow in WAC
 Cleaning and replacing air filters

CONDITIONS:

Student / trainees must be provided with the following:

 Learning Materials  Tools  Training Facility
- Work plan
- Brochure - Pull-push - Access to survey
- Catalogue rule site
- L.E on Drawing
electrical &
mechanical diagrams
- Fundamentals of
refrigeration

 Supplies and Materials
- Marker/ pen
- Bond paper/Survey
Form

METHODOLOGIES:
● Demonstration

 Lecture

ASSESSMENT METHODS:
● Direct observation
 Oral questioning
 Written examination

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Learning Outcome #2: SERVICE EVAPORATOR /CONDENSER

CONTENTS:

 Assembling and disassembling evaporator/condenser in WAC
 Cleaning procedure using high pressure washer
 Straightening of fins
 Types and application of cleaning agent
 Effects of heavily dented, corroded coil fins in unit operation
 Preventive and corrective maintenance of WAC
 Safety practices

CONDITIONS:

Student / trainees must be provided with the following:

 Equipment  Instruments  Learning Materials
- Work plan
- Portable electric - Test light - Brochure
- Safety Practices
drill - Multi-tester - Drawing
Mechanical/electri
- Portable disc - Megger cal
- diagrams, types of
grinder  Supplies and wires,

 Tools Materials - insulations,
conduits,
- Hammer - Masonry drill
- wiring devices
- Set of pliers - Hacksaw - Work safety
- Proper handling of
- Spirit level, water - Electrical
tools/equipment
hose railways - Communicating

- Plumb bob - Circuits breaker effectively

- Cross cut / rip - Masonry (e,g

saw cement, sand,

- Push pull rule etc.)

- Tri-square - Expansion

- Wire stripper Bolt/Box

- Electrician knife - Electrical Cable/

Conductor

- Convenience

Outlet

METHODOLOGIES:

● Demonstration
 Lecture

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ASSESSMENT METHODS:

 Direct observation
 Oral questioning
 Written examination

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Learning Outcome #3 MAINTAIN FAN MOTOR ASSEMBLY

CONTENTS:

 Assembling and disassembling fan motor assembly in WAC
 Proper servicing and maintenance procedures in fan motor assembly

- Proper alignment and endplays of fan motor
- Bearing and shafting
- Fan motor parts and assembly
 Types of lubricant
 Work Safety

CONDITIONS:

Student / trainees must be provided with the following:

 Equipment  Tools
- Portable electric drill - Hacksaw
- Portable disc grinder - Push-pull rule
- Welding equipment - T-square
- air-con unit - Plumb bob
- Spirit level
 Supplies and Materials - Water hose
- Masonry drill bit - Cross-cut/ rip saw
- Fastener
- Hacksaw blade - Chisel
- Marker/ pen, pentel - Hammer
- Bond paper - Masonry tools e.g. trowel

square, etc.

METHODOLOGIES:
● Demonstration
 Lecture

ASSESSMENT METHODS:
● Direct observation
 Oral questioning
 Written examination

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Learning Outcome #4 SERVICE ELECTRICAL POWER AND
CONTROL CIRCUITS

CONTENTS:

 Electrical/electric controls
 Electrical symbols and schematic diagrams
 Proper servicing and maintenance procedures in electrical power and control circuits

- Diagnosing electrical controls
- Determining terminals of electrical controls
- Grounding
- Electrical Safety / Hazards
 Work safety

CONDITIONS:
Students/trainees must be provided with the following:

 Equipment  Tools
- Refrigerator - Screwdriver
- air-con unit

 Supplies and Materials
- Marker/ pen, pentel
- Bond paper

 Instrument
- Velometer/anemometer
- Thermometer
- Clamp ammeter
- Multi-tester

METHODOLOGIES:
● Demonstration
 Lecture

ASSESSMENT METHODS:
● Direct observation
 Interview
 Written examination

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Learning Outcome #5 MAINTAIN REFRIGERATION SYSTEM

CONTENTS:

 Fundamentals of refrigeration cycle
- Tracing of refrigeration circuit

 Refrigerant system components and accessories
 Operating parameters of refrigerant system
 Diagnosing refrigerant circuit
 Reprocessing of refrigeration system

- Replacing defective components
- Repairing refrigerant leak
- Performing pressure leak test
- Performing dehydration/vacuum procedures
- Performing refrigerant charging
 Types of refrigerants
 Types of refrigerant oil
 Safe handling of alternative refrigerants
 Safety in handling nitrogen
 Montreal protocol
 Ozone depletion substances (ODS)

CONDITIONS:

Student / trainees must be provided with the following:

 Equipment  Instruments
- Window type air-conditioner - Multi Tester

- Refrigerator Unit - Clamp Ammeter

- Vacuum pump - Leak Tester

- Nitrogen cylinder and - Gauge manifold
regulator - Electronic Leak detector

- Oxy-acetylene/Mopp gas

- Recovery/recycling machine

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METHODOLOGIES:

● Demonstration
 Lecture

ASSESSMENT METHODS:

● Direct observation
 Interview
 Written examination

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Learning Experiences

DETERMINE LEARNER’S TRAINING REQUIREMENTS

Learning Activities Special Instructions
L.O 1
1. Read Information Sheet # 2.1-1 Compare answer with Answer Key
Evaluate Using Performance criteria
Clean / Replace Air Filter checklist
Answer Self-Check #2.1-1
Perform Task Sheet 2.1-1 Compare answer with Answer Key
Evaluate Using Performance criteria
L.O 2 checklist
1. Read Information Sheet #2.2-1 Compare answer with Answer Key

Service Evaporator / Condenser Compare answer with Answer Key
Answer Self-Check #2.2-1 Evaluate Using Performance criteria
Perform Task Sheet #2.2-1 checklist

2. Read Information Sheet #2.2-2 Compare answer with Answer Key
Answer Self-Check #2.2-2 Evaluate Using Performance criteria
Perform Task Sheet #2.2-2 checklist
Evaluate Using Performance criteria
3. Read Information Sheet #2.2-3 checklist
Answer Self-Check #2.2-3
Compare answer with Answer Key
Perform Task Sheet #2.2-3 Compare answer with Answer Key
L.O 3
1. Read Information Sheet #2.3-4

Maintain Fan Motor Assembly
Answer Self-Check #2.3-4
Perform Task Sheet #2.3-4

Perform Task Sheet #2.3-4A

Assignment Sheet #2.3-1A
L.O 4
1. Read Information Sheet #2.4-1
Service Electrical Power and Control

Circuits
Answer Self-Check #2.4-1
2. Read Information Sheet #2.4-2
Answer Self-Check #2.4-2

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3. Read Information Sheet #2.4-3 Compare answer with Answer Key
Answer Self-Check #2.4-3
4. Read Information Sheet #2.4-4 Compare answer with Answer Key
Answer Self-Check #2.4-4
L.O 5 Compare answer with Answer Key
1. Read Information Sheet #2.5-1 Evaluate Using Performance criteria
Answer Self-Check #2.5-1 checklist
Perform Job Sheet #2.5-1
Compare answer with Answer Key
2. Read Information Sheet #2.5-2
Answer Self-Check #2.5-2 Evaluate Using Performance criteria
checklist
Perform Job Sheet #2.5-2 Evaluate Using Performance criteria
checklist
Perform Job Sheet #3.5-3 Evaluate Using Performance criteria
checklist
Perform Job Sheet #4.5-4 Evaluate Using Performance criteria
checklist
Perform Job Sheet #5.5-5 Evaluate Using Performance criteria
checklist
Perform Job Sheet #6.5-6

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Information Sheet # 2.1-1

LO1. CLEAN / REPLACED AIR FILTER

Learning Objectives: In an air conditioning shop scenario, the trainee will be able
to identify, remove and clean air filter in different brands of window type air
conditioning unit.

AIR FILTER:

Introduction:

Preventive maintenance, proper service and troubleshooting play a big part in
keepinghumidifying equipment operating efficiently. Cleaning the components that are
in contact with the water is the most important factor. In evaporative system, these
minerals of water collect on the media, on other moving parts and in the reservoir. In
addition, algae, bacteria, and virus
growth can cause problems, even to the extent of blocking the output of the
humidifier. The reservoir should be drained regularly if possible and components,
particularly the media type, should be cleaned periodically.

DIFFERENT TYPES OF AIR FILTERS:

FIBERGLASS FILTER MEDIA :

This media may be purchased in bulk
or in frames. This material is usually an inch
thick and coated with a special non-drying,
non-toxic adhesive on each fiber. A filter
material is designed so that it gets
progressively dense as the air passes through
it.

Fiberglass filters media purchased in
bulk.

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Fiberglass filter media purchased in a
frame.

Section of fiberglass media.

BAG-TYPE AIR FILTERS

This is another type of filter that
produces greater filtering efficiencies. These
filters use fine fiberglass media within the
bags and remove microscopic particles. These
may be used in hospital operating rooms,
electronic equipment assembly rooms and
computer equipment rooms.

Bag-type filter

STEEL WASHABLE AIR FILTERS

These filters are permanent and are
washed rather than replaced. They are
usually used in commercial applications such
as in restaurants, hotels, and schools.

A steel washable filter.

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Self-Check #2.1-1

LO1. CLEAN / REPLACED AIR FILTER

CALL YOUR INSTRUCTOR who will observe you clean, remove or replace air filter to
an air conditioning unit.

Instructor’s checklist Acceptability
Yes No
1. Selection and preparation of tools and materials to be
used. ______ ______

2. Choice of method to be followed. ______ ______
______ ______
3. Setting up of the workplace, tools, materials and
equipment. ______ ______
______ ______
4. Preparation of the workpiece. ______ ______

5. Thoroughness in cleaning the air filter. ______ ______

6. Speed in completing the job (The job should be
completed in
1 hour).

7. Observance of safety precautions.

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ANSWER KEY #2.1-1
Self-Check of #2.1-1

LO1. CLEAN / REPLACED AIR FILTER

1. YES
2. YES
3. YES
4. YES
5. YES
6. YES
7. YES

Title: TASK SHEET 2.1-1
Cleaning Air Filter

Performance Objective: In air conditioning shop scenario, the trainee
must be able to practice in cleaning the air
filter by using appropriate cleaning agent and
appropriate tools needed for cleaning the air

filter

Supplies/Materials : Manual Soap (detergent). Rags

Equipment : Window-type air-conditioning unit, vacuum

cleaner, pressure washer

Tools:Standard slot-type screwdriver, Philips

Screwdriver, Fin comb, Paint brush

Personal Protective Equipment: Mask, Goggles

Assessment Method:
Demonstration, Evaluate Using Performance criteria checklist

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Performance Criteria Checklist

Task Sheet #2.1-1

CRITERIA YES NO

Did I..

 Identifies, removes and cleans parts/components*

 Checks/cleans and replaces damage filters
 Selects proper tools in dismantling evaporator /

condenser panels
 Observes proper use of tools and equipment

 Cleans evaporator/condenser, condenser cord,
plates, fins and other parts/components

 Uses cleaning agent or non-corrosive chemical in cleaning
and maintaining evaporators, etc.

 Demonstrates compliance with safety regulations*

 Communicates effectively with others*

Assessment Result: Not Yet Competent
Competent

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Information Sheet # 2.2-1

LO2. SERVICE VAPORATOR / CONDENSER

Learning Objectives: In an refrigeration and air conditioning shop scenario, the
trainee will be able to familiarize the different types and classification of evaporator
in air conditioning system and to perform cleaning / removing and / or replacing
the evaporator fins.

EVAPORATOR:

The Evaporator is the part of the low-pressure side of the refrigeration and
air conditioning system in which the low-pressure liquid refrigerant boils and
evaporates. Here the liquid refrigerant picks-up (absorbs) heat from a cooling medium
and changes it into gas (evaporation). The evaporator is commonly called freezer coil,
cooling coil, or chiller.

Two Main Types of Evaporator

1. Dry or direct expansion type
2. Flooded type

Dry or direct expansion evaporator is not
actually “dry” but has a refrigerant control
device that admits only enough liquid
refrigerant to be completely evaporated by
the time it reaches the outlet of the coil. All
the refrigerants leave the coil in a dry state
or dry vapor. The feed for such evaporator
may be either at the top or the bottom.

Direct or dry expansion evaporator

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Flooded evaporator recirculates Flooded type
the refrigerant by using surge
chamber or accumulator. The surge
chamber is a drum in which liquid
enters from metering device. The
whole surface of the evaporator coil
is in contact with the liquid refrigerant
under all load condition.

CLASSIFICATION OF EVAPORATOR:

STATIC:

Cold Plate

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Shell

Forced Air
Fin

EVAPORATOR LOCATION:

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Self-Check #2.2-1
LO2. CLEAN / REPAIR EVAPORATOR

Define the following terms:
1. Evaporator
2. Flooded type evaporator
3. Dry type evaporator

Enumeration:
1. What are the two types of evaporator?
2. Enumerate the classification of evaporator.

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ANSWER KEY #2.2-1

LO2. CLEAN / REPAIR EVAPORATOR

Definition:

1. Evaporator is the part of the low-pressure side of the refrigeration
and air conditioning system in which the low-pressure liquid
refrigerant boils and evaporates.

2. Dry or direct expansion evaporator is not actually “dry” but has a
refrigerant control device that admits only enough liquidrefrigerant

to be completely evaporated by the time it reaches the outlet of the
coil

3. Flooded evaporator recirculatesthe refrigerant by using surge
chamber or accumulator.
Enumeration:
1. Types of evaporator:
- Flooded type
- Dry type

2. Classification of evaporator:
- wall static
- cold plate
- Shell type
- Shelf type
- Fin type

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TASK SHEET 2.2-1

Title: Cleaning, Removing and / or Replacing the Evaporator

Performance Objective: In air conditioning shop scenario, the trainee
must be able to clean the evaporator heat

exchanger surfaces; remove and repair an
evaporator; pressure-wash a finned

evaporator; and straighten bent fins.

Supplies/Materials : Manual Soap (detergent). Rags

Equipment : Sample evaporator available; Paint brush; Tube
Cutter; Hacksaw; Soap and water solution; Oxy-
Acetylene; Brazing rod; Clean rag; Leak tester;
Sand paper (water proof); Steam cleaner

Tools:Standard slot-type screwdriver, Philips
Screwdriver, Fin comb, Paint brush

Personal Protective Equipment: Mask, Goggles

Steps/Procedure:

The inside and outside surfaces of the evaporator must be kept
clean for good heat transfer. Air or water being cooled must flow in and
out of the evaporator efficiently.

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CLEANING THE EVAPORATOR SURFACES:
1. Brush off dust or foreign materials

with a paint brush, as shown.

2. Blow compressed air to the
evaporators to remove dust and
foreign materials.

3. Isolate the parts to be opened from
the rest of the system.

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4. Using soap and water, clean and
dry the joints to be opened.

5. As soon as the ends of the
evaporator tubing is opened, plug
the openings using wood or cork.

6. Polish the weld or clean the brazed
joint with sand paper.

7. Test for Leaks. If leak is detected,
repeat brazing again.

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8. Test for Leaks. If leak is detected,
repeat brazing again.

9. For aluminum evaporators, repair
with an aluminum solder, aluminum
braze, aluminum weld or a special
epoxy.
- Locate the leak.
- If necessary, refer to the L.E. on
“Leak Testing”.

10. Discharge the refrigerant. If
necessary, refer to the L.E. on
“Evacuating or Flushing the System”.

11. Clean the metal around the leak
with a cloth or brush.

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12. Using a file/sandpaper, remove the
hard surface oxide.

13. Braze or weld the leak
NOTE:

If necessary, refer to the Learning
Element on “Soldering and Brazing”

14. Polish the weld or clean the
brazed joints using sandpaper.

15. Test for leaks. If a leak Is detected,
repeat brazing again.

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16. Polish the weld or clean the
brazed joints using sandpaper.

Assessment Method:
Demonstration, Evaluate Using Performance criteria checklist

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Task Sheet #2.2-1

Title: Cleaning, Removing and / or Replacing the Evaporator

Performance Criteria Checklist YES NO
Did I..

 Identifies, removes and cleans parts/components*

*Selects proper tools in dismantling evaporator panels
 Observes proper use of tools and equipment

 Cleans evaporator/condenser, condenser cord,
plates, fins and other parts/components

 Uses cleaning agent or non-corrosive chemical in cleaning
and maintaining evaporators, etc.

 Demonstrates compliance with safety regulations*

 Communicates effectively with others*

Assessment Result:

Competent Not Yet Competent

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Information Sheet # 2.2-2

LO2. CLEAN / REPAIR EVAPORATOR

Learning Objectives: In an refrigeration and air conditioning shop scenario, the
trainee will be able to familiarize and understand on how to clean the evaporator in
air conditioning system by using the high pressure washer.

PRESSURE WASHING THE FINNED EVAPORATOR:

1. Dirt insulates the condenser, thus
hampers the heat transfer. The fins
and coil of the condenser must be
clean so that the airflow through the
coils will not be insulated from the fin
or plate area and there will be efficient
transfer of heat.

- The finned condenser can be cleaned
by compressed air, nitrogen or carbon
dioxide. See figure below for
equipment to be used.

2. Set the pressure regulator of the
compressed air, nitrogen or carbon
dioxide at 6.90 kg/cm by turning the
pressure regulator valve handle
clockwise, as shown by the arrow in
the picture.

3. Slowly work the spray up and down the
fins.

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4. Direct the spray nozzle so that it is
parallel to the fins. Do not spray at an
angle to the fins because they could be
bent and may cause damage to the
coil.

5. Bring the spray nozzle up in a vertical
angle with the fins and then cross
about 2.54 cm. Bring the nozzle down
and repeat the up and down movement
of the spray.

6. Keep repeating the spraying pattern until
the entire coil is covered.

7. If the compressed air, soap and water
spray fail to thoroughly clean the
evaporator, a portable steam cleaner
may be used. (See figure below.) The
steam jet should be sprayed with the
same technique as the compressed gas
and soap and water cleaning. The fins
may be bent slightly but they can be
easily straightened with wide-nosed
pliers.

STEPS IN USING PORTABLE STEAM CLEANER

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1. Plug-in steam cleaner to run motor and
pump, as shown.

2. Position evaporator to be cleaned by
putting on top of 2 wooden blocks, as
shown.

3. Point the nozzle of the steam to the
evaporator and press the switch to
bring out the steam, as shown.

4. Slowly move the nozzle upward and
downward moving sideways to other
fins until all the evaporator area is
cleaned.

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STRAIGHTENING BENT FINS:
Bent fins may be straightened using a fin comb or wide-nosed pliers, as shown below.
PROCEDURE:
1. Insert the wide nose pliers to the bend

fins.

2. Press the wide nose pliers slightly until
you see that bends are already
straight.

3. Repeat steps one and two until bent
fins are straightened.

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LO2. Self-Check #2.2-2
CLEAN / REPAIR EVAPORATOR

CALL YOUR INSTRUCTOR who will observe you clean, remove or replace an
evaporator as well as straighten the bent fins of an evaporator.

Instructor’s checklist Acceptability
1. Selection and preparation of tools to be used Yes No

______ _____

2. Choice of method to be followed ______ _____

3. Setting-up of the workplace, tools, and equipment ______ _____

4. Preparation of the workpiece ______ _____

5. Quality of brazed portion or weldments. - Is it leak proof? ______ _____

6. Thoroughness in cleaning finned evaporators ______ _____

7. Quality of repaired bent fins. Is it straight enough after the ______ _____
repair?

8. Speed in completing the job. The job should be completed ______ _____
in 2 hours.

9. Observance of safety precautions. ______ _____

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ANSWER KEY #2.2-2
Self-Check of #2.2-2

1. YES
2. YES
3. YES
4. YES
5. YES
6. YES
7. YES

8. YES
9. YES

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Information Sheet # 2.2-3

LO2. CLEAN / REPAIR CONDENSER

Learning Objectives: In an refrigeration and air conditioning shop scenario, the
trainee will be able to familiarize the different types and classification of condenser
in air conditioning system and to perform cleaning / removing and / or replacing
the condenser fins.

INTRODUCTION:

CONDENSER:

Refrigeration in real sense is simply moving heat from a place where it is not
wanted to a place where it is not objectionable. The condenser is a device used for
removing heat from the refrigeration system. It is a component which transfers the
heat from the refrigeration system to a medium which has lower temperature than
refrigerant present in condensers; it can absorb and move heat to an ultimate disposal
point. The condenser is the door opening provided to transfer unwanted heat out of
the refrigeration system. Air and water are the two basic media in which condensers
could reject their heats. These two are selected because they are usually available in
sufficient quantities and are cheap. They are also easy to handle and are not
dangerous. Their normal temperature range is also satisfactory for liquification of
refrigerant.

TYPES OF CONDENSER:

There are three types of condensers. The name of each type is determined by
the condensing medium. An air-cooled condenser uses air as the condensing medium;
a water-cooled condenser, water and the evaporative condenser, both air and water.

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CLASSIFICATION OF CONDENSER:

STATIC

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FORCED AIR

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LO2. Self-Check #2.2-3
CLEAN / REPAIR CONDENSER

Define the following terms:
1. Condenser
2. Air cooled condenser
3. Evaporative condenser
4. Water cooled condenser

Enumeration:
1. Give the types of condenser?
2. What are the two classification of condenser?
3. Enumerate the classification of static condenser.
4. Enumerate the classification of force air condenser.

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ANSWER KEY #2.2-3

Definition:

1. Condenser is a device used for removing heat from the refrigeration
system.

2. Air-cooled condenser uses air as the condensing medium

3. Water-cooled condenser, water and the Evaporative condenser, both air and
water.

Enumeration:
1. Types of condenser:
- Water cooled
- Air cooled
- Evaporative
2. Classification of condenser:
- Static
- Force – air
3. Static
- Plate
- Fin
- Tube in wall
4. Force – air
- Plate
- Fin
- Tube

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Title: TASK SHEET 2.2-3
Cleaning Condenser

Performance Objective: In air conditioning shop scenario, the trainee
must be able to learned on how to clean the
condenser;remove and repair condenser ;
pressure-wash a finned condenser; and

straighten bent fins.

Supplies/Materials : Plastic bag; Degreasing solvent; Water hose;
Spray nozzle

Equipment : Window-type air conditioner

Tools:Standard slot-type screwdriver, Philips
Screwdriver, Fin comb, Paint brush

Personal Protective Equipment: Mask, Goggles

Steps/Procedure:
1. Remove air conditioner from cabinet.
(CAUTION: Always ask for help when lifting heavy objects.)
2. Set air conditioner close to a floor drain or outside the room
3. Wrap the fan motor with a plastic bag.
(NOTE: Water may ruin the fan motor.)
4. Remove screws that hold the condenser to fan shroud.
5. Carefully swing condenser out (Figure 1)

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CAUTION: Figure 1

Do not swing the condenser out Figure 2
far enough to avoid kinking or
breaking the refrigerator lines.)

6. Spray degreasing solvent onto
condenser.

7. Allow solvent time to work.

8. Attach water hose to hydrant.
(NOTE: If using hot water, be sure
the hose is designed for use with
hot water.)

9. Attach spray nozzle to water hose.
10. Spray condenser with water

(Figure 2).

11. Tilt air conditioner sideways so that water will run out.
12. Remove plastic bag from fan motor.
13. Dry all electrical components with a shop towel.
14. Carefully move condenser back into proper position.
15. Replace screws which hold the condenser to the shroud.

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16. Have instructor check.
17. Replace air conditioner in cabinet.
18. Clean up and put away tools and materials

Assessment Method:
Demonstration, Evaluate Using Performance criteria checklist

Task Sheet #2.2-2

Title: Cleaning Condenser

Performance Criteria Checklist YES NO
Did I..

1.Remove air conditioner from cabinet?
2.Set air conditioner close to a floor drain or outside the room?
3.Wrap the fan motor with a plastic bag?
4Remove screws that hold the condenser to fan shroud?

5.Carefully swing condenser out?

6.Spray degreasing solvent onto condenser?

7.Attach water hose to hydrant?
8.Attach spray nozzle to water hose?
9.Spray condenser with water?
10.Tilt air conditioner sideways so that water will run out?
11.Remove plastic bag from fan motor?
12.Dry all electrical components with a shop towel?
13.Carefully move condenser back into proper position?

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14.Replace screws which hold the condenser to the shroud?

15.Replace air conditioner in cabinet?

16.Clean up and put away tools and materials?

Assessment Result:

Competent Not Yet Competent

JOB SHEET #1
TRACING REFRIGERANT PATH RESTRICTIONS

OBJECTIVE: After completing this Job Sheet, you should be able to:
- trace refrigerant path restrictions; and
- identify at least three causes of the restriction.

EQUIPMENT, MATERIALS, AND AIDS YOU WILL NEED

QUANTITY UNIT DESCRIPTION
1 Refrigeration unit
1 Pressure gauge
1 Adjustable wrench
1 Leak detector

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INTRODUCTION:
The piping transports the refrigerant from one component in the system to the

next. A restriction along the refrigerant line will show trouble in the system. After
tracing and identifying the cause of the restriction, repairs can be made to restore the
proper operation of the system.
1. Connect refrigerant hose to the process

tube of the compressor, as shown.

2. Connect the pressure gauge to the
rubber hose, as shown

1. Check for leaks by using a halide leak
detector or by applying soap bubbles
on every fitting.
Refer to Learning Element “Detecting
Leaks” if necessary.

4. Start the unit by plugging, as shown.

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