Time: 2 Hours; Marks: 40
1. Psychometric Processes- Sensible Cooling and Sensible Heating, Cooling with dehumidification, cooling with adiabatic humidification, chemical dehumidification, heating and humidification, Mixing of air streams, Absorption, Dehumidifiers, Steam injection, Coil and Spray Equipment, Evaporative cooling, Air Washers, By pass Factor.
2. Principles of Load Estimating, Internal and External System Heat Gains, ventilation, air cleaning, Room sensible heat factor, effective room sensible heat factor.
3. Refrigerant controls, Types of expansion devices and sensible heat factor, construction and operation of automatic and thermostatic valves, capillary tubes, low and high pressure side float valves, testing and adjusting thermostatic expansion valves, solenoid valves.
4. Principles of heat transfer, Conduction, convection and radiation, Overall heat transfer coefficient, Use of fans, Effect of air velocity on heat transfer coefficient, Properties of insulating materials.
5. Evaporators, Types of evaporators-dry and flooded, Heat absorbed in evaporators, Water chillers, brine coolers, Methods of defrosting.
6. Condensers, Air and water cooled, and evaporative types, Heat rejected in condensers. Purging, Construction of condensers, Driers, Receivers.
7. Refrigerants, their properties and nomenclature R11, R12, R22, R502, R113, R114, ammonia, and carbon dioxide, pressure with various refrigerants in different systems, oil miscibility, solubility in water, Secondary refrigerants, Brines and Glycols.
8. Absorption refrigeration system.
9. Applications, Ice manufacture, Cold storage, Ice Cream manufacture, Dairy refrigeration etc.
10. Leak detection, Pressure Testing and Charging.