Refrigeration And Air-Conditioning Course And Certification

What is Refrigeration and Air-Conditioning?

Refrigeration is the process of cooling an area, substance, or a system to lower and/or maintain its temperature below the current one (while the heat that is removed is rejected at a higher temperature). In other words, refrigeration means artificial/man-made cooling. 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 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.

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.

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.

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 floodback that is necessary to maximise 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. 

3. COMPRESSOR

This draws low-temperature and low-pressure vapour from the evaporator through the suction line; the vapour will automatically be compressed once diverted – there will also be a rise in the temperature if the vapour is compressed.

4. CONDENSER

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; vapour will be cooled until it becomes a liquid refrigerant again, whereby it will retain some heat.

5. EVAPORATOR

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 vapour by the compressor.

6. RECEIVER

This is a temporary storage and a surge tank for liquid refrigerant, the receiver acts as a vapour seal. With a primary purpose of preserving the vapour 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 meet 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 to 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.


Student Login

Login & Study At Your Pace
500+ Relevant Tech Courses
300,000+ Enrolled Students



86% Scholarship Offer!!

The Scholarship offer gives you opportunity to take our Course Programs and Certification valued at $50 USD for a reduced fee of $7 USD. - Offer Closes Soon!!

Copyrights © 2020. SIIT - Scholars International Institute of Technology. A Subsidiary of Scholars Global Tech. All Rights Reserved.