REFRIGERATION AND AIR-CONDITIONING

WAEC SYLLABUS ON REFRIGERATION AND AIR-CONDITIONING

SCHEME OF EXAMINATION

The examinations shall consist of three papers, all of which must be taken. Papers 1 and 2 shall becomposite and will be taken at one sitting.

Paper 1:

This will consist of forty compulsory multiple choice questions. Candidates will be allowed1 hour for the paper. It will carry 40 marks.

Paper 2:

There shall be five essay questions out of which candidates will be expected to answerany four in 1 hour 30 minutes for 60 marks.

PAPER 3:

There shall be two practical questions for candidate to answer one of them within 2 hours for100 marks.

A list of materials (cutting list) shall be made available to the schools not less than two weeksbefore the paper is taken for their procurement and preparation for the examination.Candidate shall carry out the task in the presence of an examiner.

Alternatively, the Council may consider using the alternative to practical work testingmethod in the event of constraints on requisite facilities. In this case, two compulsoryquestions shall be made available for candidates to answer within 2 hours for 100 marks.The paper shall test candidates’ real life experience in the workshop, abilities to identifyand use requisite tools, use of measuring instruments and trouble shooting, etc. Freehand sketches of hand tools, circuits and wiring diagrams of refrigeration and airconditioningsystems may also be required.


DETAILED SYLLABUS

TOPICSCONTENTSPRACTICAL

1. Safety and first aid inthe workshop.

1.1. Workshop rules and regulations

1.2. Safety devices/equipment –helmet, goggles, safety boots,hand gloves, overall, apron sandbag, fire extinguishers, etc.

1.3. Accident: causes and preventiontechniques.

1.4. First Aid – materials for FirstAid, charts, posters and first aidbox, etc.

1.5. Application of first aid materials.

1.2.1 Identification and operation ofvarious types of fire extinguishers

2. Energy, matter andpower.
(a) Energy

2.1. Definition of energy

2.2. The process of energyconversion electrical tomechanical, gas to vapour,mechanical to heat.

2.3. Meaning of internal energy.

2.4. Enthalpy of a fluid substance,its pressure, volume andtemperature of internal energy.

2.5. The ph diagram of refrigerant.

2.2.1. Demonstration of conversionof mechanical to heat energye.g. rubbing of palms.

(b) Nature of matter.

2.6. State of matter – solid, liquid,gas or vapour.

2.7. Change of state of matter.

2.6.1. Demonstrate the conversionof ice block to water.

(c) power.

2.8. The meaning of power.

2.9. Calculation of power used by acompressor.

2.10. Unit of power: watts andkilowatts unit of heat: joulesand kilojoules.

3. Temperature andpressure.

(a) Temperature andits measurement

3.1. Concept of temperature.

3.2. Different types of thermometere.g. gas, resistance, liquid andthermocouple.

3.3. Temperature scale conversion
- centigrade to Fahrenheit
- Celsius to Kelvin
- Fahrenheit to rankine

3.4. International practicaltemperature
- The boiling point of oxygen182.97 º C
- The triple point of water0.01 º C
- The boiling point of water100 º C

(b) Pressure and itsmeasurement

3.5. Concept of pressure3.6. Different types of pressuremeasuring devices e.g.barometer, manometer,bourdon tube gauge.

3.6.1. Demonstration of the use of abarometer.

3.7. Pressure measurement

3.8. Uses of suction and highpressure gauges.

3.9. Effects of temperature, pressureand volume in refrigeration andair conditioning systems.

3.10. Gas law, Boyles law, Charleslaw and Dalton’s law.

3.11. Calculations involving generalgas law. Formulae:-

P 1V 1 = P 2V 2

P1/T1 = P2/T2

V1/T1 = V2/T2

P1V1/T1 = P2V2/T2

3.12 Plotting various temperaturescales

3.8.1. Demonstrate how suctionand high pressure gauges areused to determine theperformance of a refrigerant.

4. Refrigeration and airconditioning systems.

(a) Introduction torefrigeration.

4.1. Refrigeration cycle – Evaporation,compression, condensation andexpansion.

4.2. Layout diagram of refrigerationsystems.

4.3. Types and applications of thevarious forms of refrigeration.

4.4. Principles of operation of formsof refrigeration system.

4.5. Functions of the component andaccessories e.g. relay, solenoidvalves, capacitors andthermostat.

(b) Refrigerants

4.6. Definition and types ofrefrigerants

4.7. Chemical names and formulae.

4.8. Properties and uses ofrefrigerants.

4.9. Refrigerants flow controls e.g.TEV, AEV, capillary tube.

4.10. Operations of refrigerant flowcontrols.

4.6.1. Identification of refrigerant bycylinder colours.

(c) Air-Conditioningprocesses

4.11. Psychometric properties of air.

4.11.1. Demonstration of airconditioning principle bysling psychometer.

4.12. The processes of airconditioning: heating andcooling.

4.13. Latent and sensible heat,saturated and super-saturatedvapour.

4.13.1 Demonstration of thedifference between latentand sensible heat by use ofmethylated spirit on human skin.

5. Compressors,Condenses andEvaporators

(a) Compressors

5.1. Types of compressors

5.2 Construction of compressors.

5.3. Working principles ofcompressors.

(b) Condensers.

5.4. Construction of condensers.

5.5. Calculation of heat load oncondensers.

5.6. Types and functions of liquidreceiver and service valves.

5.7. Principle of operation of liquidreceiver and service valves.

5.8. Types of evaporators.

5.4.1. Demonstrate how to servicea condenser.

5.9. Construction and services ofevaporators.

5.10. Working principles ofevaporators.

5.11. Heat load estimates onevaporators.

5.9.1. Demonstrate how to serviceevaporators

6. Workshop practices.

(a) Basic tools used inrefrigeration andair-conditioningworkshops

6.1. Basic tools – hacksaw, coilspring benders, reamers, tubecutters, etc.

6.2. Tools and procedures forservicing window unit airconditioner.

6.2.1. Servicing of a window airconditioner.

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(b) Fault diagnosisand troubleshooting.

6.3. Different methods of diagnosingfaults systematic andobservation.

6.4. Common faults in refrigerationsystems and their symptoms –leakage, faulty units, faultycompressor, poor coolingand current leakage.

6.5. Techniques of effective repairsin refrigeration and airconditioningsystems.

6.6. Techniques of trouble shootingin a given system.

(c) Maintenance andTesting

6.7. Testing for leakages, polarity,insulation continuity, pressureand efficiency.

6.7.1. Demonstrate how to test forleakages, polarity continuity andefficiency.

6.8. Maintenance of compressors,evaporators, motors, condensers, valves,accumulators and contactors.

6.8.1. Demonstrate how to repairfaults in compressors,evaporators, motor condensers.

7. Installation processes

(a) Piping, Ductingand Trunking

7.1. Concept of piping, ducting andtrunking.

7.2. Piping a condenser and anevaporator.

7.3. Ducting, trunking and installationof air-conditioners.

7.3.1. Installation of a split airconditioner.

7.4. Piping, ducting and trunking tools– mallet hammer, flaring tools,silver tape, dot-punch, bendingspring, amaflex, hacksaw, PVCpipes.

(b) Motors andgenerators

7.5. Types, functions, operations andapplication of motors andgenerators.

7.6. Installation procedures formotors and generators.

7.7. Maintenance of motors andgenerators in a refrigerationsystem.

7.7.1 Servicing of motors andgenerators.

(c) Cold room

7.8. Working principles of cold room.

7.9. Cold room installationprocedures.

7.10. Factors affecting cold roomoperations.

8. Insulation processesInsulation ofrefrigeration and airconditioningsystem.

8.1. Importance of insulation ofrefrigeration and air-conditioningsystems.

8.2. Types of insulating materials –glasswool, fibre glass,polysterene foam, wood,bitumen, ceramic, etc.

8.3. Functions and properties ofinsulation materials.

8.4. Procedure for insulatingrefrigeration and airconditioningsystems.

9. Entrepreneurship.

(a) Business concept.

9.1. Concept of business enterpriseand types of businesses – soleproprietorship, partnership, limited liability, etc.

9.2. Sources of finance – loan,mortgage, shares, overdrafts,savings, etc.

(b) Marketing

9.3. Types, functions of marketingstyles.

9.4. Meaningful marketing at theleast cost.

9.5. Marketing protocol and cost.

9.4.1. Carry out a commercialmarketing survey to set uprefrigeration andair-conditioning

(c) Accounting

9.6. Principles of Accounting.

9.7. The concept of business as aseparate entity.

9.8. Ledger, trial balance andbalance sheet.

9.8.1. Preparation of ledger andbalance sheet.

LIST OF FACILITIES AND MAJOR EQUIPMENT/MATERIALS REQUIRED:

1. Complete tool box (RAC) (Number required) - 3
2. Set of oxy-acetylene brazing equipment (Number required) - 2
3. Power pillar drilling machine (Number required) - 1
4. Power grinding machine (Number required) - 1
5. Portable hand drilling machine (Number required) - 2
6. Portable table grinding machine (Number required) - 2
7. Vacuum pump (Number required) - 1
8. Recovery and recycling machine (Number required) - 1
9. Spotter recovery pump (Number required) - 2
10. Table vice (Number required) - 4
11. Workbench (Number required) - 2
12. Hand blower (Number required) - 1
13. D. O. T. recovery cylinders big size (Number required) - 1
14. D. O. T. recovery cylinders (medium) (Number required) - 1
15. Manifold gauge (Number required) - 2
16. Reamers (Number required) - 4
17. Pipe benders (various sizes) spring and mechanical (Number required) - 1
18. Ratchet wrenches (Number required) - 2
19. Hacksaw (Number required) - 4
20. Pliers (different types) (Number required) - 1 each
21. Set of screwdrivers (Number required) - 4
22. Mallet hammers (Number required) - 2
23. Ball-pein hammer (Number required) - 2
24. Electronic leak detectors (Number required) - 1
25. Electronic charging scale (Number required) - 2
26. Trolleys (Number required) - 1
27. Halogen touch light (Number required) - 1
28. Alcometer (Number required) - 1
29. Various types of refrigerant (R134A, 600A and 717)

We provide educational resources/materials, curriculum guide, syllabus, scheme of work, lesson note & plan, waec, jamb, O-level & advance level GCE lessons/tutorial classes, on various topics, subjects, career, disciplines & department etc. for all the Class of Learners

SUGGESTED READING LIST

1. Ananthranrayazan P. N. (2005) Basic refrigeration and air conditioning 3rd Edition, Tata McGrawHill, New Delhi.
2. Whitman, W. C. Johnson, W. M. (1995) Refrigeration’s Air-conditioning Technology 3rd Edition,Delmar Publisher, Albany, N. Y.
3. Rajput R. K. (2006) Refrigerant and air-conditioning 1st Edition, S. K. Kataria and Sons, Naizarak,Delhi.
4. Roy J. Dossat. Principles of Refrigeration 4th Edition, Spectrum Publishers.

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ADDRESS: 1. M. Aruna Close, Ughelli, Delta State, Nigeria

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BANK: UNITED BANK FOR AFRICA Plc (UBA)

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ADDRESS: 1. M. Aruna Close, Ughelli, Delta State, Nigeria

PHONE: +234805 5084784, +234803 5586470



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We provide educational resources/materials, curriculum guide, syllabus, scheme of work, lesson note & plan, waec, jamb, O-level & advance level GCE lessons/tutorial classes, on various topics, subjects, career, disciplines & department etc. for all the Class of Learners