4. energy efficiency - somaiya vidyavihar. energy efficiency.pdf · 2020. 10. 9. · energy...

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© Confederation of Indian Industry

Energy Efficiency


Building Energy Consumption

Break-up of energy consumption in a building

57%

5%16%

22%

Air Conditioning Area Lights

Mis Equipment Ventilation fans

2


Cooling Load Components

A Break Up Of The Heat Gain Through Various Building Components

WALL CONDUCTION

ROOF CONDUCTION

GLAZING CONDUCTION

INTERNAL GAINS (LIGHT, PEOPLE,COMPUTERS)

3%

16%

26%

55%


Who is responsible for energy efficiency in a building ?

� Landscape architect ?

� Owner ?

� Facilities group ?

� MEP consultant ?

� Architect ?

All can contribute !

3


Approach 1) Orientation

2) Envelope measures

� Wall, Glazing, Fenestration, Shading,

Skylighting, Roof

3) Equipment & systems

� Air conditioning, Lighting, Pumps, Motors, VFD

4) Controls

� BMS, Temperature, Humidity

5) Commissioning

� Additional commissioning, M & V


1) Orientation

� What is the ideal orientation ?

� East-West ?

� North-South ?

� Does not matter ?

� Buffer South and West Exposures with garages, utility rooms etc.

Saving potential : 2-3 % for 90o rotation

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2) Envelop Measures

� Glass & glazing

� How much glazing ?

� High glazing

� Tremendous daylighting

� Heat ingress

� Need to balance

� High performance glass &

glazing

� Low U-value

� Low Shading Coefficient

� High VLT (Visual Light

Transmittance)


Heat Transfer

� The three modes of heat transfer

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Heat Flows Through Windows


U-value

� U value – (W/m2.deg K)

� Heat transfer due to temperature

difference (conduction)

� Typical U values

� Single glazed glass (6mm) : 5-6

� High Performance glass : 1.7 – 3.0

(6mm+airgap+6mm)

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Shading coefficient

� Shading coefficientHeat gain thru’ a given glazing (SHGC)

---------------------------------------------

Heat gain thru’ 3 mm clear glass (0.87)

� Solar heat gain coefficient (SHGC)

� Also called as Solar factor by manufacturers

� Indicates direct heat gain

� Typical values

� Single glazed 6mm glass : 0.5 – 0.8

� High performance glass : 0.1 – 0.4


Significance of Glazing Properties

� Which one is more important ?

� U-value ?

� Shading coefficient ?

� Both ?

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Relative Heat Gain

� RHG=Direct heat gain+Conductive heat gain

=SC (630) + U (35-24)

� Direct heat gain : 90 %

� Conductive heat gain : 10 %


Walls & Roofs

� RCC Walls

� U-value : 1.95 W/m2 deg K

� Heat Storage higher

� Due to high mass

� Concrete Roof

� U value 2.5 – 3.0 W/m2 deg K

Efficient roof in a flat building

Efficient wall in multi-storied building

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Wall options

� Brick wall with insulation

� Extruded polystyrene, Expanded

polystyrene (thermocol), Glass wool

etc.,

� Brick wall with air cavity

� Hollow blocks

� Flyash bricks

� Autoclaved Aerated Concrete Blocks

Savings Potential : 3-8 %


Insulation Materials-Relative U-values(75 mm thick)

� Glass wool stuffed

� U value : 0.53 W/m2 deg K

� Thermocol

� U-Value : 0.47 W/m2 deg K

� Extruded Polysterene


� Polyurethane


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Roof Insulation

� Over-deck ?

� Under-deck ?

� Insulation

sandwiched

� Saving potential

� 3-8 % depending

on extent of roof 1: Reinforced concrete2: Separation layer3: Insulation4: Water proof membrane5: Screed6: Concrete roof deck


Wall Insulation

� External or

Internal

� Internal if brick

exterior required

� Saving potential

� 3 – 8 %

1: Cement plaster / Gypsum wall board2: Insulation3: Brick or concrete wall4: Interior gypsum or plaster

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Autoclaved Aerated Concrete Blocks

� AAC blocks

� Composed of fly ash, cement,

lime, Aluminum powder and

water

�Unique properties�Low U value: 0.67 W/m2 ok

�Reduction in temp possible : 4-5oC

� Economic Benefits� 15-20% savings in A/c Load

� Savings in Cement


Envelope measures : Typical saving potential

� Orientation :0.5-1 %

� AAC wall : 3-8 %

� Brick wall with 75mm : 3-8 %

extruded polysterene insulation

� High Albedo roofing material : 2-3 %

� Roof garden : 1-2 %

� Low-U glass & glazing : 6-8 %

� Thermal break : 1-2 %

� Roof insulation (extr.polyst) : 5-6 %

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3) Equipment & systems

� Air-conditioning

� COP: Higher than ASHRAE 90.1-2010

� VFD for supply & return fans and

pumps

� Heat recovery wheels, Economisers

� Controls & Building Management

Systems


Life cycle cost for A/C systems

Operating Cost 89%

Maintenance/Consumables 1%

Initial Inv. 10%

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Green Building – Air Conditioning

Design Stage

Conventional System

Wind Tower System

Geothermal Cooling

Earth Tunnel Cooling


Conventional Vapour Compression Cycle

Condenser

Evaporator

CompressorThrottle valve

Discharge high pressure gas

High pressure liquid

Low pressure liquid and flash gas

Suction low pressure gas

T1

T2

CHW in or air in

CHW out or air out

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Chiller Performance

COP : Amount of heat to be taken outAmount of work required

COP tested under ARI conditions:Condenser water inlet : 29.4 deg C, outlet : 35 deg CChilled water inlet : 12..2 deg C, outlet :6.7 deg C


ASHRAE 90.1-2010 Efficiency Requirements

Path A: Buildings with consistent occupancy. Eg: Office buildings, etc.,; Applicable for all types of Chillers; Path B: Buildings with variable occupancy. Eg: Hotels, Malls, etc; Applicable for Screw Chiller & Centrifugal Chiller with VFD;

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ASHRAE 90.1-2010 Efficiency Requirements

EER: Energy Efficiency RatioCOP: Coefficient of PerformanceIPLV: Integrated Part Load Value

Nad :The requirement is not applicable and cannot be used for complianceNre :There are no minimum requirements for this category.


Typical AHU System

Condensor

Evaporator

Compressor

Throttle valve

Chilled water coil

Fresh Air

Return Air

Sensor

Supply Air

Enthalpy Control

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Wind Towers

� Advantages

� Requires little / no energy

� Indoor air quality good

� Fresh air entry

� Disadvantage

� Performance dependent on wind

availability


�

CII- Institute of Quality Building, Bangalore

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Geo Thermal System

GroundBldg

Comp

Heat flow during cooling

Heat flow during heating

Refrigerant flow while heating

Refrigerant flow while cooling

� Refrigerant : Water / Environmentally safe Anti-fre eze liquid� HDPE pipes underground, Life 50 years� Length of pipes depends on area conditioned

Saving Potential : 30 – 50 %


Earth Tunnel Air Conditioning

� Concrete hume pipes laid below 4m

� Length of Pipe α Building area

� Room conditions

� Temperature

� Summer - 21-23oC

� Winter – 20 - 22oC

� RH - 50%

� Running equipment (2 HP blower)

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Earth Tunnel Air Conditioning

� Wonder Utilisation of

Nature

� Earth below 4 m

� Cooler - During Summer

� Warmer - During Winter


Lighting

� ASHRAE requirement

� Overall lighting density:< 1.0 w/sq.ft

� Trade-off allowed

� Maximum daylighting

� Daylight-cum- dimmer controls

� Occupancy sensors (toilets)

� CFL, T-5 lamps, LED

� Equipment density: 1.5 – 2.0 w/sq.ft

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4) Controls and BMS

� Why BMS ?

� Variations inevitable

� Load

� Occupancy schedule

� Climatic conditions

� Human interface minimized

� On-line corrections

BMS – An effective tool


Capability of BMS

� Centralized Control

� Monitor

� On-line interaction� Chillers

� Pumps

� Fans

� Lighting

� Measurement & Verification� IPMVP protocols

� Data generation & updating

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BMS – HVAC system


5) Commissioning

� Best of equipment, systems, controls may

be in place

� No savings if not commissioned

� Can result in 5-10 % savings

� Especially if carried out by a III party

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IGBC Green New Building Rating System - Perspectives


Energy EfficiencyCredit Title Points

Mandatory Requirement 1

Ozone Depleting Substances Required


Minimum Energy Efficiency Required


Commissioning Plan for Building Equipment & Systems

Required

Credit 1 Eco-friendly Refrigerants 1

Credit 2 Enhanced Energy Efficiency 15

Credit 3 On-site Renewable Energy 6

Credit 4 Off-site Renewable Energy 2

Credit 5Commissioning, Post-installation of Equipment & Systems

2

Credit 6 Energy Metering and Management 2

Total 28

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EE Mandatory Requirement 1

Ozone Depleting Substances

�Intent

� Encourage use of eco-friendly

refrigerants and halons free refrigerants

� To minimise negative impact on the

ozone layer



Ozone Depleting Substances

� Compliance Options

� Refrigerants

� CFC (Chloro Fluoro

Carbon) – free

(And)

� Halon-free Fire

Suppression Systems

Chimes , GurgaonGold Rated

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EE Credit 1

Eco-friendly Refrigerants


�Refrigerants used in HVAC equipment

� Low or no Ozone Depletion Potential (ODP)

and Global Warming Potential (GWP)

LCGWP + LCODP x 105 ≤ 13



Minimum Energy Efficiency

�Intent

� Optimise energy consumption to

reduce negative environmental

impacts from excessive energy use

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Minimum Energy Efficiency


� Case 1 - Air conditioned Buildings

� Option 1 - Whole Building Simulation

� Option 2 - Prescriptive Approach

(Or)

� Case 2 - Non-air conditioned Buildings

(Applicable only for Owner-occupied buildings)

� Prescriptive Approach


Case 1 - Air conditioned Buildings

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Option 1 - Whole Building Simulation

� Demonstrate building performance

compliance through simulation

� ECBC

(Or)

� ASHRAE Standard 90.1-2010, Appendix - G

� Indoor temperature

� 24 ± 2 deg C


Whole Building Simulation

� Submission

� Building energy simulation report

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Credit 2

Percentage of Energy Cost Savings over ASHRAE Standard 90.1-2010 Base case

PointsOwner-occupied

Buildings

Tenant-occupied

Buildings

Major Renovation

Buildings

6% 4% 4% 1

8% 6% 6% 2

10% 8% 8% 3

12% 10% 10% 4

14% 12% 12% 5

16% 14% 14% 6

18% 16% 16% 7

20% 18% 18% 8

22% 20% 20% 9

24% 22% 22% 10


Credit 2

Percentage of Energy Cost Savings over ASHRAE Standard 90.1-2010 Base case

PointsOwner-occupied

Buildings

Tenant-occupied

Buildings

Major Renovation

Buildings

26% 24% 24% 11

28% 26% 26% 12

30% 28% 28% 13

32% 30% 30% 14

34% 32% 32% 15

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Option 2 - Prescriptive Approach

� Meet the applicable criteria as

established in prescriptive measures

� ECBC

(or)

� ASHRAE Standard 90.1-2010


Case 2 – Non-air conditioned Buildings

(Applicable only for Owner-occupied buildings)

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Non Air-conditioned Buildings(Definition)

� Those which are not serviced and will not be serviced in the future

� Either through central air-conditioned systems or unitary air-conditioners

� Air-conditioning may be considered for critical areas

� Not more than 10% of the total regularly occupied area


Prescriptive Approach

1) Building Envelope(Baselines as per

Annexure – I)

2) Lighting

3) Air-conditioning Systems

4) Heating Systems

5) Fans

6) Pumps & Motors

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�Intent

� Verify and ensure that the building’s

equipment & systems are commissioned

� To achieve performance as envisaged

during the design stage



�Compliance Options

� Agreement with third party

commissioning authority

� Who is not involved in the design

� At least 3 years prior experience in

equipment and systems

� Document owners brief

Basically a plan

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Commissioning Plan

� Commission Plan shall include:

� HVAC systems & accessories

� Pumps & Motors

� Lighting systems

� Renewable energy systems

� CO2 monitoring system

� Energy & Water metering

� Building management system

� Sewage treatment plant

� Diesel generator sets


Commissioning Plan

� Report specific observations & variations

� Identified by the Commissioning Authority

� Post occupancy survey to verify:

� Lighting levels, temperature, relative humidity,

noise levels etc.,

� Report on green building performance

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EE Credit 3

On-site Renewable Energy

�Intent

� Encourage the use of on-site

renewable technologies

� To minimise the environmental impacts

associated with the use of fossil fuel energy


EE Credit 3



� Owner-occupied Buildings

� 1% of total annual energy consumption of

the building

� Tenant-occupied Buildings

� 2% of total annual lighting energy

consumption of the building

� Interior & exterior areas, including tenant-

occupied spaces

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EE Credit 3


* % of total energy consumption – Owner-occupied buildings

Use of On-site Renewable Energy *

(Percentage)

Points

≥ 1% 2

≥ 2% 3

≥ 3% 4

≥ 4% 5

≥ 5% 6


EE Credit 3


* % of lighting energy consumption – Tenant-occupied buildings

Use of On-site Renewable Energy *

(Percentage)

Points

≥ 2% 2

≥ 3% 3

≥ 4% 4

≥ 5% 5

≥ 6% 6

≥ 7% 7

≥ 8% 8

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EE Credit 4

Off-site Renewable Energy

�Intent

� Encourage the use of off-site

renewable technologies

� To minimise the environmental impacts

associated with fossil fuel energy use


Option 1: Off-site Renewable Energy Investments


� 50% of the total annual energy consumption


� 50% of the total annual lighting energy

consumption


occupied spaces

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Option 1: Off-site Renewable Energy Investments

Percentage of Off-site

Renewable Energy *Points

≥ 50 % 1

100 % 2


* % of lighting energy consumption – Tenant-0ccupied buildings


Option 2: Renewable Energy Certificates (RECs)


� 25% of the total annual energy consumption


� 25% of the total annual lighting energy

consumption


occupied spaces

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Option 2: Renewable Energy Certificates (RECs)

Percentage of Renewable Energy

Certificates (RECs) Purchased Points

≥ 25 % 1

≥ 50 % 2


* % of lighting energy consumption – Tenant-occupied buildings


Renewable Energy Certificates

Bombay House, MumbaiGold Rated

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EE Credit 5

Commissioning Post-installation of Equipment & Systems

�Intent

� Verify and ensure that the building

equipment & systems are commissioned

� To achieve performance as envisaged

at the design stage



� Report specific observations & variations

� vis-à-vis the Commissioning Plan

� Agreement with third party commissioning

authority

� Post occupancy commissioning

� for a period of one year

Commissioning Post-installation of Equipment & Systems

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EE Credit 6

Energy Metering and Management

�Intent

� Encourage sub-metering and

continuous monitoring

� To identify improvement opportunities

in building’s energy performance

Tenant Sub MeteringBearys Golden Research Triangle, Bangalore,Platinum Rated


EE Credit 6

Energy Metering and Management


� Case 1: Energy Metering (1 Point)

(And)

� Case 2: Building Management System

(1 Point)

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Case 1: Energy Sub-metering . . .

� Install sub-meters for at least five of the

following:

1) Interior & Common area lighting

2) Exterior area lighting

3) Municipal water pumping

4) Ground water pumping

5) Treated waste water pumping


Case 1: Energy Sub-metering

6) Renewable energy generation

7) Power backup systems (Generators sets, etc.,)

8) Elevators, Escalators, Travelators, etc.,

9) BTU meter for chilled water consumption

(Applicable for tenant-occupied buildings only)

10)Any other energy consuming equipment and systems

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Case 2: Building Management System

�BMS to control and monitor:

� Air-conditioning management system

� Lighting management system

� Renewable energy management system

� Elevator management system

� Fresh air monitoring system

� CO2 control and monitoring system

� Water management system Commit to provide annual building energy consumption data


Building Management System

Cooling Towers Temperature & RH

Chiller AHUChimes, GurgaonGold Rated

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Energy EfficiencyCredit Title Points


Ozone Depleting Substances Required


Minimum Energy Efficiency Required



Required

Credit 1 Eco-friendly Refrigerants 1

Credit 2 Enhanced Energy Efficiency 15

Credit 3 On-site Renewable Energy 6

Credit 4 Off-site Renewable Energy 2

Credit 5Commissioning, Post-installation of Equipment & Systems

2

Credit 6 Energy Metering and Management 2

Total 28

4. energy efficiency - somaiya vidyavihar. energy efficiency.pdf · 2020. 10. 9. · energy...

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