ABSTRACT
In all types of air-conditioning work a through knowledge of the b basic principle is very important. The report is divided into four chapters which cover the practical application of air-conditioner in different field. The type of operation carryout in the repair include the following. Wash of the film, replace of the compressor with a new one, replacing of the metering device with new one, servicing of the condenser. The manufacturing process of work carry out is cutting of the pan, bending and folding, riveting.
TABLE OF CONTENTS
Chapter one
Introduction
Literature Review
Air Conditioning History Background
Application of Air Conditioning
Airconditioner and Air-conditioning
Air conditioning System and Their Types
Principles/Techniques of Air Conditioning
Components of and Airconditioner
Refrigerant
Purpose of Air Conditioning
Why we Study Air-Conditioning
Chapter Two
Identification of problem/Causes of Breakdown
Trouble Shooting
Sequence of Operation
Procedure for Charging the Compressor
Air Conditioner Repair Schedule
Chapter Three
Maintenance of the Airconditioner
Aims of Maintenance
Types of Maintenance
Working Tools and their Uses
Test/Performance
Installation of the Airconditioner
Safety Precaution
Cost Analysis of Project
Material Cost of Project
Labour Cost of Project
Total Cost of Project
Problem Encountered
Recommendation
Conclusion
References
chapter one
INTRODUCTION
Repair and rehabilitation of air condition has come into existence since after the discovery of an air conditioner which broken down after a period of one. In the previous days, the selective humility of air was very low in most part of the world, this lead to uncomfortable atmospheric condition to individuals.
There was need for Engineers and scientist to make research and came to the solution of this problem. They produced an appliance to bring cooling to the temperature known as an air-conditioner. After a period of time, it developed a fault and was about to be dumped.
Before a new one can be purchased, there was need to repair and rehabilitate the faculty one to an acceptable standard for use again.
Therefore the repaid and rehabilitation of a faulty air-conditioner in approach taken to restore the functionability of the air-conditioner and make it able to air-condition the environment and brings human comfort.
LITERATURE REVIEW
THE HISTORICAL BACKGROUND OF AIR-CONDITIONING
Air-conditioning came about as a result of water soakedmat that was hanged across windows and doors to provide evaporating cooling during hot and dry season. Air conditioning came in place after the contribution of Lord Kelvin. Some of his works that leads to the discovery includes the following: establishment of the absolute temperature scale, the law of condutibility of matter and others.
Few years later, Wilks carrier conducted a research, which was published in 1911, provided the foundation for today’s air-conditioning industries. After this discoveries, it was left with the problem of refrigerants that was used in the air-conditioner which was poisonous and uncomfortable till the year 1928 when a suitable refrigerant was found.
AIR-CONDITIONING APPLICATIONS
Air-conditioning is found in homes, industries, office building, hospitals, banks, departmental stores etc.
It is used in an electric water cover, which in used to cool city water. It is used by industries for packing and shipping.
Some air-conditioning system operates as a heating system. It is used in residential central air-conditioning. Also used in automobiles air-conditioning. It has a very wide range of application that made it demand to increase day by day.
AIR-CONDITIONER AND AIR-CONDITIONING
AIR-CONDITIONER: This is a device/machine that collects air from the environment, purifies it, cool or heat and makes it more or less moisture. If also humidify and dehumidify air to supply sufficient outdoor air for ventilation. It conditions air up to a stand that it becomes less uncomfortable to human beings.
An air-conditioner also heats air to warm the environment during the dry season, it performs the cooling and heating functions depending on the type and the user.
air-CONDITIONING: It is a process that is carried out by the air-conditioner. It is a means of controlling the temperature air in a building to provide comfortable air temperature in theatres, stores, offices and homes. When all the process in an air-conditioner is being carried out, it knows as air-conditioning which results in an air-conditioned.
AIR-CONDITIONING SYSTEM OF THEIR TYPES
The smallest type of an air-conditioning system consists of a wall-mounted unit serving just the room in which it is located. In a large systems, the conditioned air is circulated around he whole building through ducts. It may consist of large metal tubes. In modern building. The structure itself often provides the ducts for circulating air.
TYPES OF AIR-CONDITIONING SYSTEMS
THE ALL-AIR TYPE: A central conditioning plant supplies all the air at a fixed temperature, smaller unit around the building provides the final temperature control. An alternative is to have two ducts one carrying cool air and other carrying warm air.
This type of system is know as the all-air air-conditioning system.
In another kind of all air system, the temperature is regulated by controlling the amount of air supplied instead of its temperature, it is know as variable volume system. If a building is to be cooled, the cold air must be provided but with this system, its temperature is not critical.
THE AIR-WATER TYPE: In the air-water system, the central plant provides only the fresh air needed for ventilation. For temperature control, each circulation water kept at a for table temperature.
THE ALL-WATER TYPE: In this system, only heat or cooling water is supplied by the central plant. Fresh air is brought in through ventilation provided in the room.
AIR-CONDITION TECHNIQUES/PRINCIPLES
In a large all-air system, fresh air from outside is first drown in through a duct. it is then mixed with recycled air from the building for only a certain amount of fresh air is required.
This provides the oxygen that we use up when we breath.
The mixed air passes through a filter section which is of two stages.
Stage I filter uses a substance like absorbent cotton. When the air passes through the fibers, any large dust particles get left behind.
Stage 2 filter removes fine particles such as cigarette smoke. It is usually done by passing the air through a series of metals plates carrying a high electrical change. The plates attract high objectives, so as air passes through, the fine particles are left clinging to the plates.
COMPONENTS OF AN AIR-CONDITIONER
There are many components that make up an air-conditioner but below are the major four parts.
Compressor: The compressor is referred to as the heart of the air-conditioner. It pumps the refrigerant gas through the entire system.
It draws cool refrigerant gas through the suction line from the evaporator freezer coils. At the same time it compresses the gas and pumps it into the discharge line. There are various types of compressor graded according to their capacities and nature of work.
CLASSIFICATION ACCORDING TO THEIR NATURE OF WORK.
CLASSIFICATION ACCORDING TO THEIR CAPACITY
CONDENSER: It is a part of the system that transfers heat from air-conditioning system to a medium, which absorbs and moves it to a final disposal points.
The condenser is the door through which unwanted heat flow out of the system. The condenser is the cooling coil for the hot refrigerant.
In this process, the refrigerant gas gives up the heat it. Removed from the inside of the system and changes it into liquid state.
DRIER STRAINER/METERING DEVICE: In the drier strainer as the hot refrigerant liquid leaves the condenser to enter the metering device, a drier strainer removes any moisture or impurities associated with it.
The metering device/capillary tube is carefully calibrated in length and inside diameter to meter the exact amount of liquid refrigerant flow required for each unit.
EVAPORATOR: This is a device in the low-pressure side of the air-conditioning system through which the unwanted heat flows into the system. The evaporator absorbs the heat into the system inorder that it may be moved or transferred to he condenser. The evaporator is also called cooling unit.
OTHER COMPONENT ARE
OVERLOAD AND RELAY: These are sensitive materials inside the air-conditioner, they serve for the purpose of controlling the compressor by tripping off when there is low or high voltage. They also supply current to the compressor.
THERMOSTAT: It is another sensitive part of the air- conditioner, it supplies the system electrical current. Also trips off the compressor when the voltage is high and after prolonged use.
FLEXIBLE CABLES: This is the copper wire that carrier the current from the current supply system with the help of plug to the air-conditioner.
JUNCTION BOX: It serves as a house of connection wires which carries current to different section inside the air-conditioner like the bulled light inside the fridge and to the compressor.
foam that covers the internal body: It is a substances that covers the internal body of the system so that cooled air from the evaporator will not be lost outside the building.
SWITCH: The switch controls the current coming into the system by putting it ON or OFF by closing and opening.
ODOR FILTER: After undergoing temperature control, the air passes through an odor filter. It absorbs large number of odor molecules from the air. It is been taken out to be reactivated from time to time.
SOUND ABSORBER: The conditioned air is normally moved round the system by centrifugal fan. Air taken in near the centre of the fan is forced outward by its large curved blades. To prevent noise from the fan reaching the main part of the building, the air is passed through a silencer. It contains the material that absorbs most of the sound energy from the air system. Air then flows along the ducts and enters the room through diffusers.
Refrigerant
In air-conditioning, the refrigerant commonly used is from –22 which can solidify or liquidity at moderately low temperature. It must posses some certain properties which make it fit for the process. A lot of refrigerant has been found very toxic brings about human discomfort but to get a fine quality refrigerant, the following properties must be seen.
PURPOSES OF AIR-CONDITIONING
Air-conditioning is meant to create human comfort when taken in the atmospheric air.
It was equally made for education purposes for students and non students to have the knowledge of air-conditioning and know the modes of it’s operation. It is used to make the oxygen we breath comfortable.
It reduces hazards and environment discomfort in air.
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