Lesson Notes, Audio Lessons, Exam Questions
Lesson Notes, Audio Lessons, Exam Questions
Access detailed Air Conditioning and Refrigeration lesson notes designed for students and instructors. These notes cover key concepts, practical techniques, and theoretical foundations essential for mastering the field.
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Download comprehensive Air Conditioning and Refrigeration lesson notes. Learn key concepts, techniques, and principles for technical mastery and exam success.
PSYCHROMETRIC PROPERTIES The properties of moist air are called psychrometric properties and the subject which deals with the behaviour of moist air is known as psychrometry. Moist air is a mixture of dry air and water vapour. They form a…
Humidification and Dehumidification The addition of moisture to the air without change in its DBT is known as humidification and removal of moisture from the air without change in its DBT is called as dehumidification. Sensible heat factor: It…
The basic functions of an expansion device used in refrigeration systems are to: Reduce pressure from condenser pressure to evaporator pressure, Regulate the refrigerant flow from the high-pressure liquid line into the evaporator at a rate equal to the evaporation…
Soldering Much refrigeration work requires soldering. Brass parts, copper tubing, and fittings are soldered. The cooling unit is also soldered. Thus, the air-conditioning and refrigeration mechanic should be able to solder properly. Two types of solders are used in refrigeration…
The refrigerator was not manufactured until the 1920s. Before that time, ice was the primary source of refrigeration. A block of ice was kept in the icebox. The icebox was similar to the modern refrigerator in construction. It was well…
The challenge in refrigeration and air conditioning is to remove heat from a low temperature source and dump it at a higher temperature sink. Compression refrigeration cycles in general take advantage of the idea that highly compressed fluids at one…
Comfort chart The Comfort Chart is a tool that helps operators determines how well air-handling equipment is providing thermal comfort for the building occupants or for a process within the facility. In designing winter or summer air conditioning system, the…
1. Cold storage The cold storage is a building designed to store certain goods like food stuffs, fruits, vegetables and dairy product within well defined temperature range and relative humidity. The temperature and humidity condition maintained inside a cold storage…
TESTING FOR LEAKS Never use oxygen to test a joint for leaks. Any oil in contact with oxygen under pressure will form an explosive mixture. Do not use emery cloth to clean a copper joint. Emery cloth contains oil. This…
The stripping or removing of wire and cable insulation is accomplished by the use of tools shown in Fig. 1-11. The knives and patented wire strippers are used to bare the wire of insulation before making connections. The scissors are…
Pressure Pressure is a force that acts on an area. Stated in a formula, it becomes: P = F / A where F = force A = area P = pressure The unit of measurement of pressure in the English…
The use of the vacuum pump may be the single most important development in refrigeration and air-conditioning servicing. The purpose of a vacuum pump is to remove the undesirable materials that create pressure in a re- refrigeration system. These include:…
Drilling Equipment Drilling equipment consists of a brace, a joint-drilling fixture, an extension bit to allow for drilling into and through thick material, an adjustable bit, and a standard wood bit. These are required in electrical work to drill holes…
Air conditioning is the process of removing heat and moisture from the interior of an occupied space to improve the comfort of occupants. Air conditioning can be used in both domestic and commercial environments. This process is most commonly used…
VAPOUR ABSORPTION SYSTEM The vapour absorption refrigeration is heat operated system. It is quite similar to the vapour compression system. VAPOUR COMPRESSION SYSTEMS The challenge in refrigeration and air conditioning is to remove heat from a low temperature source and…
In vapour absorption system the refrigerant is absorbed on leaving the evaporator, the absorbing medium being a solid or liquid. In order that the sequence of events should be continuous it is necessary for the refrigerant to be separated from…
It is impossible to install or service air-conditioning and refrigeration units and systems without using gages and instruments. A number of values must be measured accurately if air-conditioning and refrigeration equipment is to be operated properly. Refrigeration and air-conditioning units…
AIR CONDITIONING SYSTEMS Introduction: In order to maintain required conditions inside the conditioned space, energy has to be either supplied or extracted from the conditioned space. The energy in the form of sensible as well as latent heat has to…
The evaporator works the opposite of the condenser, here refrigerant liquid is converted to gas, absorbing heat from the air in the compartment. This causes the refrigerant to absorb heat from the warm air and reach its low boiling point…
TOOLS AND EQUIPMENT The air-conditioning technician must work with electricity. Equipment that has been wired may have to be replaced or rewired. In any case, it is necessary to identify and use safely the various tools and pieces of equipment.…