Refrigeration And Air-Conditioning Course And Certification
What is Refrigeration and Air-Conditioning?
Refrigeration is human made cooling or artificial cooling which involves the cooling of an area, substance or a system by heat removal mechanism. Heat in the substance or space is removed from a low-temperature reservoir and then transferred to a high-temperature reservoir. The process of heat transfer is primarily driven by mechanical means, but can also be driven by magnetism, heat, laser, electricity, or other related means.
Air Conditioning is the process of eliminating heat and moisture from the inside of a room or area to ensure that its occupants are more comfortable. Air Conditioning can be used in both domestic and commercial applications. The process of Air conditioning is regularly used to achieve a more relaxed environment inside a closed space, primarily for humans and other animals; however, air conditioning is also used to cool and dehumidify rooms that are filled with heat-producing electronic devices, such as power amplifiers, computer servers, and to display and store some very delicate products, such as artworks.
Difference Between Refrigeration and Air-Conditioning:
Refrigeration Mechanisms and Air-Conditioning Mechanisms are almost the same. The only major difference between refrigeration and air conditioning is the supply and circulations of gases.
1. Air Conditioners have circulation systems designed to project cool air away from the units. Air Conditioners usually use a fan to distribute the conditioned air to an occupied area such as in a building or on a car to improve the thermal comfort and the quality of the air indoors. Electric refrigerant-based AC units vary from small units that can be used to cool a small bedroom, which can be carried by a single adult, to massive units that can be installed on the roof of office towers to cool down an entire building. The cooling effect is basically achieved through a refrigeration cycle, but seldom evaporation or free cooling is employed.
2. Refrigeration Units have circulation systems designed to retain coolant in a confined space. Refrigeration systems circulate cool liquids and gases through a series of tubes and vents. Cool air from within a refrigerator is sucked into a compressor that recycles the gas through the tubes. Refrigeration has many purposes, which include, but not limited to household refrigerators, cryogenics, industrial freezers, and air conditioning. Heat pumps can also use the heat output of the process of refrigeration, and also may be developed to be reversible, but are otherwise similar to air conditioning units.
Components of a Refrigeration System
Here are the six main components of a refrigeration system;
1. CAPACITY CONTROL SYSTEM
The capacity control system regulates the power and energy consumption, although it can also manage dehumidification or decrease compressor cycling. The on/off cycling of the compressor is the simplest form of capacity control.
2. THERMOSTATIC EXPANSION VALVE (TXV)
This is located at the end of the liquid line before the evaporator. TXV is a device that controls the amount of refrigerant that flows to the evaporator. In the TXV, you will find the flood back that is necessary to maximize the productivity of the evaporator while stopping the extra liquid refrigerant from going back to the compressor.
This device also helps to separate the high pressure and the low-pressure sides of an air conditioning system.
This draws low-temperature and low-pressure vapor from the evaporator through the suction line; the vapor will automatically be compressed once diverted – there will also be a rise in the temperature if the vapor is compressed.
This device can extract heat from the refrigerant. Fans placed above the condenser unit draw air over the condenser coils. The temperature of condensation should range from around -12°C to -1°C; vapor will be cooled until it becomes a liquid refrigerant again, whereby it will retain some heat.
The main purpose of the evaporator is to remove unwanted heat from the product through liquid refrigerants. The liquid refrigerant must be at a low-pressure. This low-pressure can be determined by two factors – one is the heat being absorbed from the product to the liquid refrigerant and the other is the removal of low-pressure vapor by the compressor.
This is temporary storage and a surge tank for liquid refrigerant, the receiver acts as a vapor seal. With a primary purpose of preserving the vapor moving down the liquid line to the expansion valve, receivers can be made for both horizontal and vertical installation.
Features of Refrigeration And Air-Conditioning
1. Compressor: An air compressor in the process of cooling is a device that transforms electrical or mechanical power into potential energy stored in pressurized air, known as compressed air and it is used in refrigeration and cooling for many purposes.
2. Heat Transfer: The compressor in the cooling departments pushes the hot compressed gas to the finned condenser coil in the outdoor side of the air conditioner or refrigerator where fans blow cool air from outside over the coil and through the fins, taking away the heat from the refrigerant and transferring it to the air outside.
3. Turns Hot Air Into Liquid: When enough heat has been extracted from the space or refrigerant, it then condenses into a warm liquid that is then passed under high pressure to an expansion valve which turns the refrigerant into a cool, low-pressure liquid.
4. Heat Absorption: When the refrigerant enters the evaporation coil where the pressure is much lower, it is chemically made to evaporate into a gas.
How the Refrigeration System Works
The compressor restricts the refrigerant vapor, thereby raising its pressure, and pushes it into the coils on the outside of the refrigerator. When the hot gas in the coils meets the cooler air temperature of the kitchen, it becomes a liquid. Now in liquid form at high pressure, the refrigerant cools down as it flows into the coils inside the freezer and the fridge. The refrigerant absorbs the heat inside the fridge, cooling down the air. Last, the refrigerant evaporates to a gas, then flows back to the compressor, where the cycle starts all over.
Benefits of Refrigeration And Air-Conditioning
1. It allows you to control the temperature in an area or space.
2. It lets you remove pollutants from the air.
3. It extends product life by freezing them in the refrigerator.
4. It prevents computer servers from overheating.
5. It keeps the cooling chain and it breaks the bacterial developments from food items.
6. Save time for cleaning activities.
Why Study Refrigeration And Air Conditioning
1. After this course, you would have knowledge of operating major cooling systems.
2. Knowledge gotten from this course would make you qualify to set up refrigeration and cooling systems in homes and offices.
3. This course would take you on the fundamentals and essentials of how cooling and refrigeration works.
4. Job opportunities and career advancement in cooling industries.
5. Self-employment opportunity and consultancy.
Refrigeration And Air Conditioning Course Outline
Refrigeration and Air Conditioning - Introduction
Refrigeration and Air Conditioning - Principles Of Cold Production
Refrigeration and Air Conditioning - Components Of Refrigeration
Refrigeration and Air Conditioning - Thermodynamics Of The Refrigeration Cycle
Refrigeration and Air Conditioning - Modular Training Systems
Refrigeration and Air Conditioning - Assembly, Fault Finding, Maintenance
Refrigeration and Air Conditioning - Heat Pumps And Ice Stores
Refrigeration and Air Conditioning - Video Lectures
Refrigeration and Air Conditioning - Exams And Certification