PRESENTATION BY:

RAMESH KUMAR SHARMAMECHANICAL ENGINEER

1. INTRODUCTION2. A/C SYSTEM – AVAILABLE OPTIONS3. RATING SYSTEM-GRIHA4. DESIGN OF HVAC SYSTEM FOR

GREEN BUILDING5. INITIATIVE BY NTPC6. A/C SYSTEM ENVISAGED FOR

UPCOMINGPROJECTS

7. CONCLUSION

1. Centralized A/C system Chilled Water Type

- Water Cooled- Air Cooled

D-X Type - Water Cooled - Air Cooled

2. Localised A/C system Packaged Type Air Conditioners Split/Window Type Air Conditioners Precision Air Conditioners

3. Variable Refrigerant Flow/Volume

NORMALLY ADOPTED FOR LARGE CAPACITY DISTRIBUTED LOADS

SYSTEM REQUIRING CHILLED WATER,CONDENSER WATER PUMPS,COOLING TOWERS AND MANY AHUs

FOR CENTRAL CONTROL ROOMS, CONTROL EQUIPMENT ROOMS, UPS& BATTERY CHARGER ROOM,SERVICE BLDGS, ADMN BLDGS,ETC.

USED FOR COMPACT AREAS REQUIRING ONLY ONE OR TWO AHUs

AVAILABLE UP TO 100TR NO CHILLED WATER PUMP SCROLL TYPE

NON-CONDENSING/CONDENSING UNITS ARE USED.

SIMILAR TO D-X TYPE BUT PAC IS A COMPACT UNIT WITH AHU AS INTEGRAL PART.

AVAILABLE UP TO 15 TR USED IN SMALL CONTROL ROOMS

THESE UNITS ARE D-X TYPE ARE AIR COOLED USED WHEN LOADS ARE LESS AND

ONLY WINDOW SPACE IS AVAILABLE AVAILABLE UP TO 3TR. CASSETTE TYPE A/Cs AVAILABLE UPTO

4TR

THESE UNITS ARE DEVELOPED CONSIDERING FOLLOWING ASPECTS:CLOSE TEMPERATURE AND RH CONTROLS.24X7 OPERATIONENERGY EFFICIENCY- CONSIDERING 24X7

OPERATION.HIGH SENSIBLE LOAD AND LESS LATENT

HEAT.

TO ACHIEVE ABOVE REQUIREMENTS FOLLOWING ARE INCORPORATED.HIGH ENERGY EFFICIENT SCROLL

COMPRESSORS ARE EMPLOYED.LARGER SIZE EVAPORATOR COIL FOR HIGH

CFM TO MEET HIGHER SENSIBLE HEAT. DEDICATED HUMIDIFIER AND

DEHUMIDIFICATION FEATURES.DESIGNED TO OPERATE EVEN IN WINTER.

SIMILAR TO SPLIT TYPE OF AIR CONDITIONING.

THE REFRIGERANT FLOW IS VARIED BY USING INVERTER CONTROLLED VARIABLE SPEED COMPRESSOR TO RESPOND TO CHANGES IN THE COOLING OR HEATING REQUIREMENT.

BY THE COMBINATION WITH THE INVERTER COMPRESSOR AND THE CONSTANT SPEED COMPRESSOR, THE COMFORTABLE ROOM CONDITION WILL BE OBTAINED BY CHANGING THE COMPRESSOR OPERATION CONDITION.

VRV CONDITIONS AIR FOR EACH ROOM INDIVIDUALLY AS PER LOAD REQUIREMENT.

Freely Selectable Type of Indoor Units

VRV SYSTEM CAN WORK BOTH AS CENTRALIZED AND LOCALISED SYSTEM.

OPERATING COST OF THE SYSTEM IS MINIMIZED BY USE OF VARIABLE REFRIGERANT FLOW CONCEPT.

MAKE UP WATER IS NOT REQUIRED. VRV SYSTEM CAN OPERATE AT PART

LOAD. TOTAL PIPING LENGTH FROM

OUTDOOR TO INDOOR UNIT CAN BE AS MAXIMUM AS 150M.

LESS SPACE REQUIREMENT AND ALSO EASE IN INSTALLATION IN EXISTING BUILDING.

IDEAL FOR CONSTANTLY CHANGING OCCUPANCY.

DESIGN FLEXIBILITY. SILENT IN OPERATION.

CAPITAL COST OF THE SYSTEM IS HIGH. LIMITED TO OFFICE BUILDINGS. A SEPARATE FRESH AIR SYSTEM IS

REQUIRED. NO CONTROL OVER HUMIDITY. SKILLED MANPOWER REQUIRED FOR

MAINTENANCE AT SITE.

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Sl.No. Area to be air-conditioned Type of air conditioning equipment/system

—————————————————————————————————————————1. Control Tower areas Vapour absorption machine and screw (including Control room, /centi type chiller unit with chilled water system Control Equipment room, UPS room and SWAS) .-Control room for Electrostatic Precipitator -Service Building

2. Administrative Building Screw/Centrifugal type chiller unitswith chilled water system

3. Township Auditorium Screw type chiller units with chilled water system

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Sl.No. Area to be air-conditioned Type of air conditioning equipment

——————————————————————————————————————4. Offsite Control rooms of PAC/Ductable & Non ductablevarious pump houses Split Air Conditioner

5. Switchyard Control room Water Cooled/Air Cooled Scroll/ Building Reciprocating type units

6. Water System Control Bldg Air Cooled scroll/reciprocating type

7. Office building in metros VRV system

8 . Server room (independent) Precision AC

REDUCTION IN DEPLETION OF NATURAL RESOURCES.

GRIHA (GREEN RATING FOR INTEGRATED HABITAT ASSESSMENT). NATIONAL RATING SYSTEM OF INDIA.

Points scoredPoints scored RatingRating

50-6050-60

61-7061-70

71-8071-80

81-9081-90

91-10091-100

Selection of Chillers Selection of Pumps Selection of Cooling Tower Selection of AHU’s Selection of Insulation Selection of Refrigerant Indoor Air Quality Noise & Vibration Control

USE SCREW/CENTRIFUGAL/SCROLL COMPRESSORS.

CHILLER SHOULD BE AHRI CERTIFIED. MIN. COP OF CHILLER( WATER COOLED)

SHOULD BE 5.4 (FOR 150-300 TR) AND 3.05

FOR AIR COOLED CHILLERS ABOVE 150 TR.

AVOID OVER DESIGNING OF CHILLERS.

PRIMARY AND SECONDARY PRIMARY AND SECONDARY ZONAL CHILLED WATER ZONAL CHILLED WATER PUMPING SYSTEM MUST BE PUMPING SYSTEM MUST BE ENVISAGED.ENVISAGED.

EACH SECONDARY PUMP EACH SECONDARY PUMP PROVIDED WITH VFD; VARIES PROVIDED WITH VFD; VARIES CHILLED WATER FLOW CHILLED WATER FLOW THROUGH THROUGH

THE COOLING COIL OF AHU’S THE COOLING COIL OF AHU’S AS PER DEMAND WHICH AS PER DEMAND WHICH RESULTS IN ENERGY SAVING.RESULTS IN ENERGY SAVING.

CONDENSER WATER PUMP CONDENSER WATER PUMP PROVIDED WITH VFD TO VARY PROVIDED WITH VFD TO VARY WATER FLOW ACCORDING TO WATER FLOW ACCORDING TO CHILLER REQUIREMENTCHILLER REQUIREMENT

INDUCED DRAFT, CROSS OR COUNTER FLOW. BIRD SCREEN ON TOP OF

TOWER. COOLING TOWER FAN

PROVIDED WITH VFD.

VARIABLE VOLUME TYPE VARIABLE VOLUME TYPE WITH DOUBLE SKIN WITH DOUBLE SKIN CONSTRUCTION.CONSTRUCTION.

USE CENTRIFUGAL FAN USE CENTRIFUGAL FAN WITH VFD WHICH WITH VFD WHICH RESULTS IN ENERGY RESULTS IN ENERGY SAVING.SAVING.

CONFORM TO IS STANDARDS BE ODP FREE (CRITERIA NO.-27) HAVE HIGH NOISE REDUCTION COEFF.

(NRC) (CRITERIA NO.-29) MAX. R VALUE OF INSULATION 2.1 M2-

K/W AND U-VALUE 0.409 W/M2-K AS PER ECBC CODE

BE RECYCLABLE INSULATION SHOULD BE CFC/HCFC

FREE

Resin bonded glass wool / Resin bonded mineral wool / Expanded Polystyrene

ODP FREE (CRITERIA ODP FREE (CRITERIA NO.27)NO.27)

HAVING MINIMUM GWPHAVING MINIMUM GWP.. CFC/HCFC FREE.CFC/HCFC FREE. CHOOSE EITHER HFC’S CHOOSE EITHER HFC’S

OR AZEOTROPIC OR AZEOTROPIC REFRIGERANTS.REFRIGERANTS.

Currently we are demanding for anyone out of these refrigerants:Currently we are demanding for anyone out of these refrigerants:R-134a / R-410AR-134a / R-410A

SCREW/CENTRIFUGAL CHILLER FOR MAIN PLANT A/C SYSTEM. NO VAM

PRIMARY AND SECONDARY CHILLED WATER PUMPS.

VFD IN SECONDARY CHILLED WATER PUMP. AHUS WITH VFD DRIVEN FAN. CONDENSER WATER PUMP FITTED WITH

VFD. COOLING TOWER FAN VFD DRIVEN. USE OF R-134A INSTEAD OF R-22 AS R-

134A HAS A TEWI 13% LESS THAN R-22.

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Sl.No. Area to be air-conditioned Type of air conditioning equipment/system ---------------------------------------------------------------------------------1. Control Tower areas Screw/Centrifugal type chiller unit with chilled water system & AHUs with VFD Control Equipment room, UPS room and SWAS) Control room for Electrostatic Precipitator

2. Service Building Screw/centrifugal type chiller unit withprimary & secondary chilled water system& VFDs

3. Administrative Building Screw/Centrifugal type chiller unitswith primary & secondary chilled water system& VFDs

4. Township Auditorium Screw/scroll type chiller units with chilled water system & AHUs with VFD

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Sl.No. Area to be air-conditioned Type of air conditioning equipment

——————————————————————————————————————5. Offsite Control rooms of Cassette/ Non ductablevarious pump houses Split Air Conditioner

6. Switchyard Control room Water Cooled/Air Cooled Scroll Building type units with VFD driven AHUs

7. Water System Control Bldg Air Cooled scroll type with VFD driven AHUs

8. Office building in metros VRV system

9. Server room (independent) Precision AC

NTPC has initiated the process of designing green building and has decided to construct all its non-plant buildings and township buildings for all upcoming projects with minimum GRIHA 3-star rating.

Name of BuildingName of Building RatingRating

Administrative Building, Administrative Building, Service BuildingService Building

4-Star4-Star

CanteenCanteen 3-Star3-Star

Name of BuildingName of Building RatingRating

Hospital, Bal Bhawan & Ladies Hospital, Bal Bhawan & Ladies Club, Training Center, etc.Club, Training Center, etc.

4-Star4-Star

GM Bungalow, Guest House, GM Bungalow, Guest House, Quarters (all type), Auditorium, Quarters (all type), Auditorium, Community Center, Swimming Community Center, Swimming Pool, etc.Pool, etc.

3-Star3-Star