central air conditioning system
Post on 12-Sep-2014
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DEPARTMENT OF ESTATE MANAGEMENTFACULTY OF ARCHITECTURE, PLANNING AND SURVEYING,
UNIVERSITI TEKNOLOGI MARA, PERAK
GROUP ASSIGNMENTDIPLOMA IN ESTATE MANAGEMENT
EMT 257 BUILDING SERVICES & EQUIPMENT
TITLE: CENTRAL AIR CONDITIONING SYSTEM
PREPARED FOR: MISS NUR ILYANA BAZLIN BINTI MD NOR
NAME MATRIC NO.NUR HIDAYAH ADILAH BINTI
MALEK2011641458
NURUL ATIQAH BT MAHADI 2011260236NOR AIN BT MOHD MUSTAFA
KAMAL2011297788
FATEN ATHIRAH BT OTHMAN 2011289296MUHAMMAD FAISAL B
NGATIMIN2011296496
DEFINITION OF AIR-CONDITIONING
Process of altering the properties of air mainly of two things which are temperature and humidity to more favorable conditions
Process of altering the properties of air mainly of two things which are temperature and humidity to more favorable conditions
TYPES OF AIR-CONDITIONING SYSTEM
CENTRAL AC SYSTEM
Split-system
An outdoor metal cabinet contains the condenser and compressor, and an
indoor cabinet contains the evaporator
Packaged Unit
The evaporator, condenser, and compressor are all located in one cabinet, which usually is placed
on a roof or on the ground
PORTABLE AC SYSTEM
Consists of a mobile self-contained air conditioning unit that is placed on the floor inside a room and discharges exhaust heat using a hose vent through an exterior wall
A bit noisier
ROOM AC SYSTEM
Also known as window or wall
units. When cooling a single room or small
space
Inexpensive and
easy to install
Noisier, physical
appearance that is
unattractive, lower efficiency and poor constant
temperatures
DUCTLESS AC SYSTEMalso known as a mini split system
perfect where there is no overhead attic or crawl space
Consists of the
following components
such as indoor air handling
unit, outdoor
condensing
unit and remote controller
CASE STUDY
DEFINITION OF CENTRAL AC SYSTEM
The central air – conditioning system is suitable for a large building which is required a very high air cooling such as cinema, hotel, hospital, supermarket and etc. This system is commonly use in a new building.
DEFINITION OF CENTRAL AIR-CONDITIONING SYSTEM
A method of structural cooling in which a
centralized unit cools and dehumidifies air before circulating it throughout
the building
The main unit is located outdoors or in isolated area of a
building
Method of cooling
To cool down the hot and high pressure refrigerant gas that travels from compressor to condenser.
It provides ease during the condensation which occurs in the condenser where refrigerant gas changes into liquid form.
Water Cooling MethodWater from cooling tower
is used to remove heat
Cooling tower functions to cool down the hot water
that flows from the condensed water return
pipe (CWR)
Italso supplies cooled water to condenser through
condensed water supply pipe.
The process of heat extraction in cooling tower
is known as evaporation process whereby the water is cooled by a fan and the
heat will evaporate into air to cool the water
There is a ball float inside the cooling tower to ensure
the water is at specified level
COMPONENTS
COMPRESSOR A pump or other machine that increases the pressure of a
gas. Three basics types of compressor:i. Reciprocatingii. Rotary screwiii. Rotary centrifugal Types of compressor are specified by the number of
compression stage, a cooling method, lubrication and packaged or custom built
AIR HANDLING UNIT ROOM Also known as AHU Shaped like box that content equipment with
a blower, condenser, compressor and expansion valve
A function is to suck air from the rooms and let it pass through air filters then discharging the cooled air back to the rooms.
Located at the top of building and the door of room is always closed
Removable panels are installed with reason a personnel can enter for maintenance
RETURN AIR INLETS This component is to regulate and
extract air from a room and recycle it Use of any ventilating, heating and air
conditioning The air will force air process which blows
through the duct Located either in hallway or in the ceiling
at AHU Rooms
COOL AIR DISPENSER A place that a cooled air passes over the
air filter and is through by the supply air ducts into the space which to be air conditioned
Located at the top of ceiling and it will come in several types
TYPE OF GAS THAT USED AS REFRIGERANT
Chlorodifluoromethane also known hydrochlorofluorocarbon (HCFC)
Usually known as R22 gas Very high quality and competitive price
Condenser Condenser is a component which acts as
a heat exchanger that is being used in air-conditioning system.
The purpose of condenser is to change the hot gas that is released by the compressor to liquid form
Types of condenser;Air-cooled condenser
Water-cooled
condenser
Evaporative
condenser
Case study: Water-cooled condenser
It uses water from the cooling tower to remove the heat from the high temperature gas in the compressor.
The capacity of water-cooled condenser depends on;1. the temperature from the water2. the amount of water circulated 3. temperature of the gas. The capacity increases with the temperature
difference between gas and water. There are two pipes of condenser which are
Condensed Water Return (CWR) and Condensed Water Supply (CWS).
Cross-section of water-cooled condenser
The condenser in Air Handling Unit Room
Cooling method in condenser
Water that flows in the condensed water
supply (CWS) pipe will enter condenser
The water is used to absorb heat from the
hot compressed refrigerant gas that
flows from compressor
Once the heat is absorbed, the cooled water will turn into hot water as it has
absorbed heat
It will flow back through condensed water return (CWR) pipe and enter cooling tower for the
process of cooling
Cooling tower at Dewan Seri Iskandar
PROCESSCooling tower and
AHU controller buttons are switched on.
Water tank supply water to cooling
tower.
Cooling tower cooler and filter the water
before it enters condenser.
In AHU, compressor compress the refrigerant
used; R22 gas causes it to turn into hot and highly
pressured gas.
The gaseous travel into condenser and cold water
used to cool the hot gaseous. Condensation process occur
here.
Refrigerant turns into highly pressured
liquid and enters TXV.
TXV controls the flows of the refrigerant which causes it to
reduce pressure. When pressure reduced, refrigerant expand and
its temperature drops
Refrigerant enters evaporator coil. Lower pressure in
evaporator causes refrigerant to evaporate. It absorbs heat and
turns cold gaseous.
COMMON PROBLEMS
Bad odour
Faulty wiring
Leaky ducts and low airflow
Low refrigerant
MAINTENANCERefrigerant
gas
Clean the filter at the air –
conditioning system
Electric controlBelting
Cleaning
ADVANTAGES
Improves indoor air
quality
Level of indoor noise is almost
negligible
Maintains a constant temperature and
humidity throughout the conditioned space
DISADVANTAGES
The size for the AC unit
The cost of installing the
system
THANK YOU