AIR-CONDITIONING & REFRIGERATION TECHNOLOGY CLASS XI
COURSE OBJECTIVES After successfully completing the two year + 2 stage Vocational Course the student would have acquired relevant appropriate and adequate technical knowledge together with professional skills and competencies in the field of Air Conditioning and Refrigeration Technology so that he is properly equipped to take up gainful employment in this vocation. Thus he should have acquired-
A. understanding of:
(a) the relevant basic concepts and principles in basic science subjects (Physics, Chemistry and Mathematics) so that he is able to understand the different vocational subjects,
(b) the basic concepts in engineering drawing,
(c) the concepts and principles of working of refrigeration and air conditioning equipment,
(d) the knowledge of testing, faults identification and repair procedures in respect of refrigeration and air conditioning equipment
(e) the knowledge to prepare estimates for cost of repair/installation/maintenance/ overhauling jobs.
B. adequate professional skills and competencies in:
(a) testing, fault location and repairing of refrigeration and air conditioning equipment,
(b) installing and commissioning of refrigeration and air conditioning equipment,
(c) carrying out preventive maintenance of refrigeration and air conditioning equipment,
(d) dismantling, overhauling and reassembling of refrigeration and air conditioning equipment.
C. a healthy and prefessional attitude so that he has:
(a) an analytical approach while working on a refrigeration or air conditioning equipment,
(b) an open mind while locating/rectifying faults in a refrigeration or air conditioning equipment,
(c) respect for working with his own hands,
(d) respect for honesty, punctuality and truthfulness.
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Scheme of Studies: Class XI
1 2 3 4 5
S.No. Subject Periods/Week Examination Total
Theory Prac. Total Theory Prac. Marks
Marks: Hrs. Marks: Hrs.
1. Language I 7 7 100 3 100
2. Language II or 7 7 100 3 100
Mathematics (041)
As per Academic Stream
3. General Foundation 4 1 5 80 3 20 3 100
Course
4. Vocational Elective Papers
I. Engg. Science 1 7 8 70 3 30 3 100
a. Engg. Drawing (0) (4) - (40) - - - -
b. Workshop (1) (3) - (30) - - - -
Technology
II. Air Conditioning & 3 5 8 40 3 60 3 100
Refrigeration I
III. Air Conditioning & 3 5 8 40 3 60 3 100
Refrigeration II
5. Physical & Health 2
Education
Additional (optional) Papers
I. Applied Mechanics 3 2 5 60 3 40 3 100
II. Electrical Engg. 2 3 5 60 3 40 3 100
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GENERAL FOUNDATION COURSE Class XI
(Same as given in Electrical Technology on Page No. 11)
ELECTIVE I
ENGINEERING SCIENCE Class XI
(Same as given in Electrical Technology on Page No. 13)
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ELECTIVE II
AIR CONDITIONING AND REFRIGERATION I
3 Hours Class XI Marks: 40
1. Introduction
Meaning of Air Conditioning and Refrigeration. Brief history of Air Conditioning and
Refrigeration. Applications of Refrigeration. Concept of System, its boundary, and
Surroundings, Principles and processes involved in production of low temperatures--
expansion of a liquid with flashing, reversible adiabatic expansion of a gas, irreversible
adiabatic expansion (throttling) of a real gas, thermoelectric tooling, adiabatic
demagnetization. Unit of Refrigeration. Energy Balance of a Refrigeration Machine--
heat energy absorbed from the system, heat rejected to surroundings, and work done.
Carnot cycle, and Reverse Carnot Cycle. Coefficient of Performance. Comparison of
heat engine, heat pump and refrigeration machine. Comparison of heat pump and electric
resistance heater. Rating of Refrigeration Machines.
2. Refrigeration Systems. Air Refrigeration cycle, applications, and its limitations. Vapour
Compression Cycle. Representation of Vapour Compression Cycle on temperature--
entropy and pressure-enthalpy diagrams. Effect of sub-cooling, Super heating, change
in suction pressure and discharge pressure on coefficient of performance. Deviation of
actual cycle from the theoretical cycle. Simple mathematical calculations with pressure-
enthalpy charts. Energy Balance of basic refrigeration systems. 12
3. Working of a Mechanical Refrigerator, Water Cooler, etc., Refrigeration tools and
materials, tubing,cutting, bending, flaring,joining, tube fittings, instruments and gauges,
drills, taps, dies, valves, gaskets, refrigerants, cylinders. Human safety. 5
4. Compressors. Pressure-volume diagram of a compressor. Types of compressor --
reciprocating (semi-hermetic, hermetic and open types), rotary, centrifugal and crewed
type. Working of compressor. Difference between ammonia and freon compressors.
Volumetric efficiency. 5
5. Compressor construction. Valves, pistons, connecting rods, crank shafts. seals, oil
circulation, hermetic and semi-hermetic units. Cooling of windings. Mufflers. 5
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PRACTICAL
AIR CONDITIONING AND REFRIGERATION I 3 Hours Marks: 60
1 Study of Tools and materials, Instruments and Gauges.
2. To learn proper techniques of cutting, fitting, reaming, bending, flaring of soft and hard copper tubing, swedging, etc.
3. To learn brazing of copper tubing.
4. To understand the construction and functions of reciprocating compressors, condensors, and evaporators.
5. To study a hermetic unit and its testing.
6. To study pressure gauges and testing them in a dead weight tester.
7. Saturation pressure and saturation temperature. Measurement of Water and Refrigerants.
8. Measurement of Temperature during throttling expansion of a Gas.
9. Energy Balance of a Refrigeration machine.
10. To study Domestic Refrigerator, Water Cooler, etc.
11. Study of various types of compressors, dismantling and assembling compressor.
12. Testing of reciprocating compressors.
ELECTIVE III
AIR CONDITIONING AND REFRIGERATION III
3 Hours Class XI Marks: 40
1. Meaning of Alternating Currents and Voltages, Wave Shape, Maximum, Average and
R. M.S. Values, Phase Difference. 4
2. Series and parallel circuits. Application of Kirchhoff's Laws, Star and Delta connections.
Measurements of current, voltage and power. Representation of circuit elements by
proper symbols. Circuit diagrams. 4
3. Synchronous Machines. 4
4. Induction Motors. Principles of working, construction details, and performance of Slip
Ring Squirrel Cage, Single Phase and Polyphase Induction Motors. Use of Megger for
testing. Rewinding of single phase and polyphase motors. Detecting faults. Testing of
Motors. 8
5. Psychrometry-Composition of air, moist air, vapours and gases; specific humidity,
absolute humidity, degree of saturation, relative humidity, Dry Bulb Temperature, Wet
Bulb Temperature, Dew Point Temperature, Wet Bulb Depression, Dew Point
Depression, Dalton's Law of Partial Pressures. Enthalpy of moist air. Adiabatic
Saturation Temperature. Introduction to Psychrometric Chart and Psychrometers. 8
6. Human comfort, Concept of effective temperature, Comfort Zone. 4
7. Applications of Air Conditioning. Comfort. Industrial and Process Air Conditioning.
Study of Window-type Air Conditioners, package units, Central Air Conditioning
Plants. 4
8. Measurement of air velocity and flow. 4
PRACTICAL
AIR CONDITIONING AND REFRIGERATION II 3. Hours Marks: 60
1. Measurement of humidity.
2. Measurement of air-velocity and flow.
3. Study of room air conditioner.
4. Study of Package Units.
5. Performance Testing of Air-Conditioner and measurement of capacity.
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6. Charging and testing of air-conditioner.
7. Measurement of Voltage, Current, Power etc.
8. Series and parallel circuit arrangement and testing.
9. Making Star-Delta Connections.
10. Study of synchronous Machines and Components.
11. Study of single phase and three phase induction motors.
12. Detecting faults in Motors such as short-circuiting between phases, grounding open circuit etc.
13. Testing of motors.
14. Making electric circuit diagrams.
ADDITIONAL SUBJECT (OPTIONAL)
I. APPLIED MECHANICS Class XI
(Same as given in Electrical Technology on Page No. 21)
II. ELECTRICAL ENGINEERING Class XI
(Same as given in Structure & Fabrication Technology on Page No. 93)
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