hvac systems packaged
TRANSCRIPT
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HVAC SYSTEMS
UNIT-2
BUILDING SERIVCES ANDINTERGRATION - I
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PACKAGED AIR CONDITIONING
Packaged HVAC systems consists of pre-assembled, off-the-shelf equipment that
provided space heating, cooling and ventilation to small and medium spaces.
These units are used commonly in places like restaurants, telephone exchanges,
rooms, small halls, etc.
AIR CONDITIONING SYSTEMS
WINDOW AND
SPLIT AIRCONDTIONERS
PACKAGED AIR
CONDITIONER
CENTRAL AIR
CONDTIONING
UP TO 5 TONS BEYOND 20 TONS
3,5,7,10,15 TONS
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PACKAGED AIR CONDITIONING
In packaged air conditioners all the
important components of the air
conditioners are enclosed in a single
casing like window AC.
The conditioned air are transferred to
the space to be conditioned through
ducting which is usually hidden in the
ceiling and wall of the building.
The unit is placed outside the house, a
special room in a building or even on
top of a roof.
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PACKAGED AIR CONDITIONING
Components
Compressorusually hermetic or semi-hermetic
type for operation on 380/400 Volts 3 Phase is used.
Water-cooled or Air-cooled condenser.
Electrical Panel.Thermostatic Expansion Valve.
Air Filter.
Front Panel & Return Air Grill.
Evaporator Coil.
Evaporator Fan And Housing.
Heating and Humidifying Componentsmay be included in the unit. Dehumidification is
needed for cooling mode during summer and Humidification for heating mode during winter.
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LOCATION
The packaged unit can be mounted within the air conditioned space with
discharge air plenum or in a separate room from where the air distribution duct
is taken to the conditioned space. While deciding location for the packaged
unit, provision must be kept for proper servicing of the unit.
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TYPES OF PACKAGED AC
The major types of Semi- centralized systems
(packaged systems) are:
One piece systems (Unitary Packaged Systems): Packaged Air Conditioners with Water Cooled Condenser.
Packaged Air Conditioners with Air Cooled Condensers.
Two pieces systems (Split system).
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TYPES OF PACKAGED AC
Depending on the cooling system used, Unitary Packaged
system is divided into two types:
1. Water cooled condenser above 5 ton
2. Air cooled condenser below 5 ton
The capacity of air-cooled type is lower than that of water-cooled
condenser using the same compressor.
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WATER COOLED PACKAGED AC
In these packaged air conditions the condenser is cooled by the
water.
The condenser is of shell and tube type, with refrigerant flowing
along the tube side and the cooling water flowing along the shell
side.
The water has to be supplied continuously in these systems to
maintain functioning of the air conditioning system.
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WATER COOLED PACKAGED AC
the compressor is located at the bottom along with the condenser(refer the figure below).
Above these components the evaporator or the cooling coil is located.
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WATER COOLED PACKAGED AC
The air handling unit comprising of the centrifugal blower and the air
filter is located above the cooling coil.
The centrifugal blower has the capacity to handle large volume of air
required for cooling a number of rooms.
From the top of the package air conditioners the duct comes out that
extends to the various rooms that are to be cooled.
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AIR COOLED PACKAGED AC
In this packaged air conditioners the condenser of the refrigeration
system is cooled by the atmospheric air.
There is an outdoor unit that comprises of the important components
like the compressor, condenser and in some cases the expansion
valve.
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AIR COOLED PACKAGED AC
The outdoor unit can be kept on the terrace or any other open place where the
free flow of the atmospheric air is available.
The fan located inside this unit sucks the outside air and blows it over the
condenser coil cooling it in the process.
The condenser coil is made up of several turns of the copper tubing and it is
finned externally.
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AIR COOLED PACKAGED AC
The packaged ACs with the air cooled condensers are used more
commonly than the ones with water cooled condensers since air is
freely available it is difficult maintain continuous flow of the water.
The cooling unit comprising of the expansion valve, evaporator, the air
handling blower and the filter are located on the floor or hanged to the
ceiling. The ducts coming from the cooling unit are connected to the
various rooms that are to be cooled.
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TWO PIECE SYSTEM (SPLIT SYSTEM)
In this system, the evaporator is separate from the
condenser/compressor.
These are commonly found in residential and small commercial
installations with capacity ranges varying 1 to 50 TR and suitable for
an area of 100 10000 square feet.
The new ductless systems which can be conveniently mounted on
the ceiling or wall are in this family.
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TWO PIECE SYSTEM (SPLIT SYSTEM)
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TWO PIECE SYSTEM (SPLIT SYSTEM)
A split system describes an air conditioning or heat pump system
that is split into two sections - an outdoor section and an indoor
section.
The outdoor unit is comprised of a compressor and condenser and
is located outside usually on the ground but sometimes on the roof.
The indoor section, usually located in an interior closet or garage,
consists of a fan, indoor cooling coil, furnace, and filter.
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AIR QUANTITIES
In the air distribution, centrifugal fans are usually provided at the
evaporator side which can develop higher static pressure. The
higher the static pressure, the better the air throw to the room is.
Air distribution is done through ducts and grills. The air quantities
are usually in the range of 10-11.3 cubic meter/min (350-400 cfm)
per tonne.
In critical application such as computer room which need higher
rate of air flow, higher capacity fans with air flow up to 550 cfm are
provided. This usually need to be factored in during the design of
the system.
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HEATING OF PACKAGED AC
The packaged unit can also be provided with winter heating package or
humidification package.
Packaged heat pumps offer heating and cooling using heat pump
technology.
Packaged air conditioners cool your home and can heat it as well,
using electrical strip heat.
Packaged gas-electric units offer all-in-one air conditioning and natural
gas-powered furnace performance.
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ADVANTAGES
Space efficiency all components are contained in one location, making it
ideal where indoor space is at a premium.
Energy-efficient heating and cooling performance.
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LIMITATIONS
Large multi-storey buildings where multiplicity of the compressors may
entail subsequent maintenance problems.
Where the length of air distribution ducting may exceed approx 20 m.
Where the vertical distance of air-cooled condenser from the packaged unit
exceeds about 10 m. The sum of horizontal and vertical distances should be
generally kept within 15 m.
Special applications like sterile rooms for hospitals and clean room
applications where high filtration efficiency is desired.
Operation theatres where 100 percent fresh air is needed and fire hazard
exists depending on the type of anaesthesia being used.
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The End.
Thank you!
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LITRATURE CASE STUDY
Nagoya Lucent Tower
Nagoya, Japan
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BUILDING OUTLINE
Name :Nagoya Lucent Tower
Site area : 14,100.54m2
Business owner : Ushijima District Redevelopment Union
Design & supervision :Nikken Sekkei Ltd.
Constructed by : TAISEI Corporation
Completed in : January 2007
Structure :Steel construction, partly reinforced concrete
Height :Building height 180m
Number of floors : 3 floors underground, 40 floors above
ground
Application :Offices, Shops, Parkings
Building area :115,200.34m2
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Air-conditioning system
Mitsubishi Electric Air-heat
source
CITY MULTI R2 system
Zoning : Temperature control
80-150m2per unit
OA processing units : 2 units per
floor
Outdoor units : 6-8 units per
floor
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Central Air-conditioning Systems are commonly
used for this size of building; however, to make
it possible to run simultaneous cooling or
heating operations whenever they are required,
even during overtime or on weekends,
Mitsubishi Electrics CITY MULTI R2 series was
chosen.
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High static pressure
outdoor units are installed
on the balcony in the
northwest or thesouthwest direction.
OA Processing package
unit
The heat load is reduced
by collecting the heatexhausted from the room
and using it to heat
ventilating air entering the
room.
The outdoor units are
installed in the northwest
direction to avoid the great
heat load generated from
the sunlight from the west.
Great space saving was realized by
installing the outdoor units collectively
on a balcony on each floor.
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New HFC refrigerant, zero ozone
depletion potential is used.
Exhaust air duct for
outdoor unit can be
concealed in the grille.
Installed on eachfloor
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Heat reflection
glassThe heat load is
reduced by reflecting
the sunlight entering
the room.
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600 mm square grid ceiling
makes it easy to change the
position of the partition.
Ceiling concealed indoor
unitTo provide high-quality air, pre-
filter and high-performance filter(disposable) are equipped with
all indoor units.
Reusable filter frame is used
to reduce waste
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Discreet indoor unit matching the interior dcor.
Either cooling or heating operation according to eachusers individual preferences.
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THE END
THANK YOU!