Central air conditioner unit is an energy moving or converted machines that are designed to cool or heat the entire house. It does not create heat or cool. It just removes heat from one area, where it is undesirable, to an area where it is less significant.

Central air conditions has a centralize duct system. The duct system (air distribution system) has an air handler, air supply system, air return duct and the grilles and register that circulates warm air from a furnace or cooled air from central air conditioning units to our room. It returns that air back to the system and starts again.

It uses Ac refrigerant (we may know it as Freon) as a substance to absorb the heat from indoor evaporator coils and rejects that heat to outdoor condenser coils or vice verse.

TABLE OF CONTENTS

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWELDGEMENT

ABSTRACT

DEFINITION OF TERMS

TABLE OF CONTENT

CHAPTER ONE

• INTRODUCTION
• AIM/ OBJECTIVE OF THE PROJECT
• SIGNIFICANCE OF THE PROJECT
• ADVANTAGES OF THE PROJECT
• LIMITATION OF THE PROJECT
• TYPES OF CENTRAL AC
• APPLICATION OF THE PROJECT
• SCOPE OF THE PROJECT
• ADVANTAGES OF THE PROJECT

1.10   PROBLEM OF THE PROJECT

CHAPTER TWO

LITERATURE REVIEW

2.0      LITERATURE REVIEW

2.1     HISTORICAL BACKGROUND OF AIR CONDITIONER

2.2     ELECTROMECHANICAL COOLING

2.3     REFRIGERANT DEVELOPMENT

2.4     REFRIGERATION CYCLE

2.5       HEAT PUMP

2.6      EVAPORATIVE COOLING

2.7      FREE COOLING

2.8      HUMIDITY CONTROL

2.9      DEHUMIDIFICATION AND COOLING

2.10    TYPES OF CENTRAL AIR CONDITION

CHAPTER THREE

DESIGN METHODOLOGY

3.0      METHODOLOGY

3.1     SCHEMATIC DIAGRAM OF AN AIR CONDITIONER

3.2     PICTORIAL DIAGRAM OF CENTRAL UNIT AC

3.3     PARTS OF CENTRAL AIR CONDITIONERS

3.4      WORKING PRINCIPLE OF AN AIR CONDITIONER WORK

3.5      CENTRAL AC UNIT AIR CONDITIONER INSTALLATION

3.6     MATERIALS AND TOOLS

3.7     CENTRAL UNIT AIR CONDITIONER INSTALLATION STEPS

CHAPTER FOUR

4.1       AIR CONDITIONING CALCULATIONS

         4.2         COOLING CAPACITY

4.3         IMPORTANT FACTORS FOR CHOOSING CENTRAL AC
4.4         CALCULATION FOR SIZING AN AIR-CONDITIONER

4.5      CENTRAL UNIT AC MAINTENANCE TIPS

CHAPTER FIVE

• CONCLUSION, RECOMMENDATION AND REFERENCES
• CONCLUSION
• RECOMMENDATION
• REFERENCES

CHAPTER ONE

1.0                                                        INTRODUCTION

Air conditioning is the process of altering the properties of air (primarily temperature and humidity) to more comfortable conditions, typically with the aim of distributing the conditioned air to an occupied space such as a building or a vehicle to improve thermal comfort and indoor air quality. In common use, an air conditioner is a device that lowers the air temperature. The cooling is typically achieved through a refrigeration cycle, but sometimes evaporation or free cooling is used. Air conditioning systems can also be made based on desiccants.

In the most general sense, air conditioning can refer to any form of technology that modifies the condition of air (heating, cooling, (de-)humidification, cleaning, ventilation, or air movement). However, in construction, such a complete system of heating, ventilation, and air conditioning is referred to as heating, ventilation, and air conditioning.

The central air conditioning comes from the fact that the system conditions the entire building from one large central location in your home. This system cools and dehumidifies the air, then blows the cool air into your duct system and out through the supply air registers located in each room.

In stark contrast, window A/C units cool only one room or area. Trying to cool an entire home with a window unit in each room would require not only the inconvenience of managing each separate unit, but it would also require more energy and be excessively noisy.

Central air conditioning systems are typically combined with the furnace system, if your home has one (or use a dedicated air handler if it doesn’t), and both use the same electrical system and duct-work.

1.2                                       AIM/OBJECTIVE OF THE PROJECT

The main objective of this work is to construct a complete physical central ac. At the end of this work student involve will be able to:

1. identified all the accessories of an ac and their functions
2. Understand the working principle of an ac
3. Differentiate between different types of air conditioner, and at the end will be able to install central air conditioner unit.

1.3                                         SIGNIFICANCE OF THE PROJECT

Air conditioners make air cooler by circulating it through a freon mechanism, similar to what happens in a refrigerator. They are functionally different from fans, because fans don’t actually cool air, but only make it feel cooler by moving it around. The advantage of air conditioners is that they increase comfort levels during hot weather, but they can also present various disadvantages.

Most people use air conditioners to stay more comfortable in their homes or offices during hot and humid summer weather. Under extreme conditions, air conditioners may keep elderly and other vulnerable people safer from heat-induced health problems. Air conditioners are used in many commercial settings not only for increased comfort but for decreasing heat stress on delicate machinery such as computers, and reducing food spoilage in grocery stores and restaurants.

1.3                                              ADVANTAGES OF PROJECT

There are many advantages to the central air conditioner system that can make the investment worthwhile. They are as follows:

Cleaner Air: A central air conditioning system uses filters to help improve the quality of your air. This helps eliminate pollen, dust and lint from the air.

Effective Circulation: This type of air conditioning system is the most effective way to circulate cool air through your entire home.

Reduced Noise: Window units make much more noise than central air conditioners. In comparison, the central system is almost imperceptible.

More Space: The central system is located outside of your house. This creates more space for you inside and keeps your house looking modern.

Easy to Use: From a single control panel, you can set the time and temperature at which you want the unit to operate.

Multiple Functions: There are units available that can double as a heating system. This allows you to both heat and cool your home with one simple unit.

Central air conditioning units are becoming the standard. They are easy to use and keep your home looking updated.

1.4                                           LIMITATION OF THE PROJECT

Air conditioners use a lot of electricity. This creates both financial disadvantages for the people who have to pay for the power, and more generalized environmental disadvantages caused by power production. Because a large percentage of electricity is created by coal-burning power plants, air conditioning contributes indirectly to the release of greenhouse gases and other pollutants. In addition, according to The Independent, spending too much time in an air-conditioned environment can contribute to health problems such as asthma, tightness in the chest and other respiratory ailments.

In poorly designed buildings, air-conditioning is sometimes used to make up for poor design and lack of insulation. Well-designed buildings can orient themselves to the sun in a way that reduces summer heat gain, using shade trees and insulation to reduce the effect of high temperatures on the interior climate. Even when air conditioners are being used, these measures will reduce their workload, decreasing their power usage and increasing their lifetimes. The advantages of air conditioners can, therefore, be maximized when used in conjunction with environmentally sound design and common sense.

1.5                        TYPES OF CENTRAL AIR CONDITIONING SYSTEMS

The most common type of central air conditioning is the split system, which features a condenser outside the home, and a fan-and-coil system inside, connected by pipes carrying refrigerant. However, not every home can accommodate the ductwork needed to install central air. Split ductless systems are an option for those homes because they offer the feel of central air.

Central Air Conditioning

Central air-conditioning systems use ducts to distribute cooled air throughout the house. In a “split system,” the most common design, refrigerant circulates between an indoor coil and a matching outdoor condenser with compressor. The refrigerant cools the air, dehumidifying it in the process; a blower circulates air through ducts throughout the house. A variation is the “heat pump,” a type of system that functions as heater and cooler.

Split Ductless Systems

Split ductless systems have an outside condenser and one to four indoor blower units, or more, mounted high on the wall. Tubing connects these parts and circulates refrigerant. The tubing, along with an electric and drain line, is run through about a 3-inch hole hidden behind each indoor unit. Each indoor unit cools the room in which it’s installed and has its own remote control. Split ductless systems need no ductwork, making them easier to add to homes without existing ducts. They can be more expensive than window air conditioners, and professional installation is recommended. While not technically central air, the cooling they provide can feel like a central air system.

1.6                                          APPLICATION OF THE PROJECT

There are many different ways to apply central air-conditioning to a structure. The method used depends on a number of factors, but the type of heating system is probably the dominant one. The following are the most common types of cooling applications:

1. Water chiller cooling: A water chiller is used to add cooling and dehumidification to steam or hot-water heating systems. A refrigeration-type water chiller consists of a compressor, condenser, thermal expansion valve, and evaporator coil. The water is cooled in the evaporator coil and pumped through the system.

The boiler and water chiller are installed as separate units, each with its own circulator (pump), or with one circulator in the return line. Hot water from the boiler is circulated through the convectors for heating, and cold water is circulated through the same piping from the water chiller for cooling purposes.

Each convector unit contains a blower to force the air across the convector coil.Water condensed from the coil during the cooling operation is trapped in a drip pan and discarded through a drain connected to the convector. Some convectors also contain a filter for air cleaning. The room convectors in a water chiller cooling system are usually designed for individual control.

The same piping carries both the chilled and hot water to the room convectors, but it must be insulated to minimize condensation during the cooling operation.

Water chillers are available as separate units or as a part of a complete package containing the boiler. Separate water chiller units are used when cooling must be applied to an existing steam or hot water heating system.

2. Split-system cooling: Another method of applying central air-conditioning to a steam or hot-water heating system is to add forced-air cooling. This type of cooling application is sometimes referred to as a split-system installation—that is to say, a system split or divided between one type of heating (conventional steam or hot water) and another type of cooling (forced air). This results in some confusion because the term split system is also used to refer to the separation of components in a year-round central air-conditioning system using forced warm-air heating and cooling. Three typical methods of applying forced-air cooling to a steam or hot-water heating system.
3. Year-round air-conditioning: In a year-round air-conditioning system, the heating and cooling units are combined in a single cabinet. This combined package heats, cools, humidifies, dehumidifies, and filters the air in the structure as required. The unit may have an air-cooled, a water-cooled, or an evaporative-type condenser. The arrangement of the ductwork will depend in part on the type of condenser used in the unit.
4. Central cooling packages: A central cooling package is a unit designed for central air-conditioning applications. It consists of a cooling coil and the refrigeration equipment and will provide the necessary cooling and dehumidification as conditions require. These units are available with their own fans and filters, or they may be installed to use the filter and blower of the existing heating equipment

The method used to install a central cooling package will depend on whether the unit has an air-cooled or water-cooled condenser. If an air-cooled condenser is used, provisions must be made to carry outdoor air to and away from the condenser. Typical installations in which an air-cooled condenser is used, some typical methods of applying a central cooling package in which a water-cooled condenser is used. In this installation, the compressor and air-cooled condenser unit are located outdoors. The evaporator coil, fan, and heating appliance are located indoors in the conditioned space.

5. Cooling coils: Cooling can be applied to a warm-air heating system by installing an evaporator coil or a cold-water coil in the ductwork. The evaporator coil is the low-side section of a mechanical refrigeration sys- tem. The evaporator coil is installed in the ductwork above the furnace. It is connected by refrigerant piping to the condenser coil and compressor installed outdoors.

1.7                                                 SCOPE OF THE PROJECT

Central air conditioner unit is an energy moving or converted machines that are designed to cool or heat the entire house. It does not create heat or cool. It just removes heat from one area, where it is undesirable, to an area where it is less significant.

Central air conditions has a centralize duct system. The duct system (air distribution system) has an air handler, air supply system, air return duct and the grilles and register that circulates warm air from a furnace or cooled air from central air conditioning units to our room. It returns that air back to the system and starts again.

It uses Ac refrigerant (we may know it as Freon) as a substance to absorb the heat from indoor evaporator coils and rejects that heat to outdoor condenser coils or vice verse.

1.8                                          ADVANTAGES OF THE PROJECT

Improves indoor air quality. Level of indoor noise is almost negligible. Maintains a constant temperature and humidity throughout the conditioned space. Central AC system provides uniform distribution of conditioned air throughout the whole building or space.

1.9                                              PROBLEM OF THE PROJECT

• The size for the AC unit is large.
• The cost of installing the system is high.

CHAPTER TWO

2.0                                                    LITERATURE REVIEW

2.1                       HISTORICAL BACKGROUND OF AIR CONDITIONER

The basic concept behind air conditioning is said to have been applied in ancient Egypt, where reeds were hung in windows and were moistened with trickling water. The evaporation of water cooled the air blowing through the window. This process also made the air more humid, which can be beneficial in a dry desert climate. In Ancient Rome, water from aqueducts was circulated through the walls of certain houses to cool them. Other techniques in medieval Persia involved the use of cisterns and wind towers to cool buildings during the hot season…