Hvac Systems Packaged

8/21/2019 Hvac Systems Packaged

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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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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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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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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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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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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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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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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!

Hvac Systems Packaged

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