Strategic Overview for Building Energy Efficiency

Preparing for the Next Decade International Conference on Energy Efficient Building Design

28th to 30th November 2016, New Delhi

Ashok B Lall

URBANIZATION TREND IN INDIA

NITI AAYOG PROJECTION OF DEMAND

-

10.0

20.0

30.0

40.0

50.0

60.0

2012 2017 2022 2027 2032 2037 2042 2047

Residential Space requirement (Billion m2)

Urban Rural

NITI AAYOG PROJECTION OF DEMAND

URBANIZATION TREND IN INDIA

URBAN HOUSING DEMAND

Currently 4-5 million households in the middle and low income categories

require housing in urban areas. Out of these 2.1 million homes are

required in seven major cities alone.

MAJOR SHIFT IN HOUSING TYPOLOGIES IN THE FORMAL HOUSING SECTOR

Embodied Energy

Embodied Energy: Building Structure & Finishes

Rationale Given that the window of opportunity for reversing climate

change has a horizon of the next ten years and also that the boom of residential building construction is expected to be at its height in the same decade , the contribution of embodied energy to CO2 emissions draws our attention .

Carbon dioxide emissions on account of the energy consumed

in production of residential buildings (Embodied energy ) , as against their consumption of the operational energy, will be significant in the context of rapid urban development .

This is on account on three factor

the adoption of construction materials compared to

traditional construction method

switch over to multistory frame construction using

reinforced cement concrete

relatively modest operational energy consumed in the

residential sector .

0

200

400

600

800

1000

1200

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

kWh

/m2

Years

Embodied Energy (kWh/m2) Operational Energy (kWh/m2)

At a conservative estimate the impact of embodied energy at the start of a residential buildings life is as much as operational energy spent over 10 years .

The Multiplier Effect of Embodied Energy in Construction Materials and Methods

COMPRESSED INTO ONE DECADE!

We can surmise that we have an explosion of CO2 emission on our

hands on account of high embodied energy methods of

construction

50% addition of built-space to existing stock

X

30% increase in embodied energy per unit area

X

over 63 cities of 1 million plus population today

Embodied Energy: Building Structure & Finishes

Methodology A data base of currently valid embodied energy in production

of materials in India taking into account improved industry practices was established .

Embodied Energy analysis of typical multistory building shows that

approximately 80 percent of the embodied energy of the total buildings is attributed to structural systems and external walls .

The structural and external walling systems embodied energy is calculated for following types of buildings using the construction materials data of a representative building of each type :

A. Building as usual - G+3 Hybrid Structure using burnt brick for walling . - G+8 RCC Frame With burnt brick infill . B. Environmentally conscious design - G+3 Hybrid Structure using load bearing Fly ash brick wall . - G+10 with Aerated Concrete Block Walling . Embodied Energy and Co2 Emissions per Unit area of net residential

space of the above examples is compared .

Embodied Energy Reinforcement steel - 27.3 MJ/Kg Cement - 3.2 MJ / Kg

Concrete

23%

Reinforcement

Steel55%

Brickwork

8%

Fenestration

6%Plaster

2%

Paint

2% Flooring

4%

Embodied energy %

Cement

18.35%

Sand

0.00%

Glass

2.19%

Stone

2.46%

Aggregate

1.20%

Steel

63.26%

Timber/Wood

0.27%

Bricks/Blocks

8.16%Others

4.11%

Cement

Sand

Aggregate

Steel

Timber/Wood

Glass

Stone

Bricks/Blocks

Others

Cost of materials

Cement

13.96%

Sand

3.39%

Aggregate

5.47%

Timber/Wood

16.36%

Steel

34.71%

Others

0.67%

Bricks/Blocks

7.43%Tiles

1.57%Stone

12.16%

Glass

0.29%

Ferro cement

concrete

3.98%

Cement

Sand

Aggregate

Timber/Wood

Steel

Ferro cement concrete

Others

Glass

Stone

Tiles

Bricks/Blocks

Material distribution by embodied energy % Material distribution by mass % Weight of materialsin kg

Others

1.34% Cement

7.75%

Aggregate

20.87%

Sand

15.95%Bricks/Blocks

44.18%

Steel

2.86%Stone

6.43% Timber/Wood

0.47%Glass

0.16%

Cement

Sand

Aggregate

Steel

Timber/Wood

Glass

Stone

Bricks/Blocks

Others

Cost distribution by material %

ANALYSIS

EMBODIED ENERGY IN CONSTRUCTION

Giving preference to low rise buildings (G+4) in residential

development and using low embodied energy materials for

external walling of a potential 20 -40 % reduction in EE/Sq. M. of

residential space compared to BAU .

For low rise buildings, considerable

reduction in

embodied energy

might be possible by

careful designing and

using materials with

low embodied

energy.

The range of CO2

emissions shows that in a well designed low

rise building emissions

are 30-40% less than an average high rise

building incorporating

a RCC frame

structure.

LOW EMBODIED ENERGY MATERIALS Options = Resilience

Growing dependence on refrigerant based air conditioning for thermal comfort.

Growing dependence on personalized motorized transport.

FUTURE OF THE URBAN MIDDLE CLASS

Sample Household Survey

The data for Abhiyan Apartments in Delhi (78 households) for the year 2007-08, 2008-09, 2009-10 shows a trend of increased average monthly electricity consumption per household.

LIGHTING 8%

KITCHEN 17%

AC 39%

CEILING FAN 17%

ENTERTAINMENT 16%

OTHERS 3%

There is an emerging trend of houses with EPI above 80 kWh/sq.m./year which are typically houses with 2 or more air conditioners and 4 or more occupants. This trend is visible in both climate types.

In a typical Chennai home air-conditioning and ceiling fans electromechanical aids for comfort consumes approximately 55 % of the energy bill .

Simple Passive Design : Insulate

Simple Passive Design : Shade

Simple Passive Design : Ventilate

3 ways reduction in air conditioning demand Lowering peak load Reducing diurnal period of demand Reducing seasonal period of demand

Simple Active Design : Integrate evap. cooling

Residential, Commercial, Institutional buildings Insulate Replace windows Add external adjustable shading LED Lighting Efficient radiant cooling system

PASSIVE UPGRADE ACTIVE RETROFIT

Residential, Commercial, Institutional buildings Insulate Replace windows Add external adjustable shading LED Lighting Efficient radiant cooling system

PASSIVE UPGRADE ACTIVE RETROFIT

INSTITUTE FOR RURAL RESEARCH & DEVELOPMENT, GURGAON

SOLAR ACCESS FOR SOLAR CITIES roof area to floor area ratio

TIME TO MANDATE ENERGY EFFICIENCY

Shade Ventilate Insulate

LEGISLATING AND MANDATING

Warn industry two years in advance of coming compliance standards

Make utility supply conditional on compliance

Global experience indicates that legislation is a must It starts with simple steps Can become more demanding progressively Takes at least a decade to alter market behavior and user expectations

LEGISLATING AND MANDATING

ADVANCING KNOWLEDGE Education, Training, Practice

INTEGRATION : Evaporative cooling and building mass - PROTOTYPE

On site T Beams and Hollow block

production for floor constructions

1. Vertical cooling ducts formed between

parallel load bearing masonry walls ,

which act as coolth stores .

2. Horizontal cooling ducts formed by

Precast Hollow Block floor construction ,

which also become coolth stores .

Evaporative cooling system

integrated with floor and wall

structure is a shared facility

between neighbors and requires a

co-operative management

arrangement.

P

Proposal for the REHAU core temperature control (CCTC) pipe size: RAUTHERM S 20x2,0mm pipe spacing: 15cm, pipe mounted on the lower reinforcement This piping layout of the CCTC is a first proposal, it has to be clarified: - occupied areas - distances to structural walls and beams - distances to ducts and air outlets - flow rate - position of the manifolds, in this proposal: manifold in the suspended ceiling below the chilled slab - pipe position in the concreted slab SECTION OF THE SLAB:

pipes near the manifold with a spacing of less than 15cm and pipes outside the chilled slab led in corrugated pipe The position and size of the space for air conditioning or air outlets has to be checked

RADIANT COOLING Plus Ceiling Fans

The planning of the structural system, external windows, placement of lights and fans in the slab and other services is such that each sub-divided space continues of receive: Radiant cooling for the RCC slab. Fresh Air Supply Daylight from the windows Artificial lighting Ceiling Fan Sprinkler system Fire Detector

REFLECTED CEILING PLAN

21

22.1

21.7

21.8

21

23.9

Air temp. 28.7

Air temp. 28.4

Surface temperatures Air temperature

INTEGRATION : refrigerant/ evaporative

cooling and building mass

Supplementary air velocity

I

INTEGRATION : at sub city scales - exploiting demand diversity and

temporal demand patterns and heat sinks

Residential, Commercial, Institutional buildings Insulate Replace windows Add external adjustable shading LED Lighting Efficient radiant cooling system

PASSIVE UPGRADE ACTIVE RETROFIT

Residential, Commercial, Institutional buildings Insulate Replace windows Add external adjustable shading LED Lighting Efficient radiant cooling system

PASSIVE UPGRADE ACTIVE RETROFIT

New Vaastu Shade

Ventilate Insulate

CONSUMER AWARENESS CAMPAIGN

THE EXTERNAL CHALLENGE

Nighttime land surface temperatures for Delhi, compiled from ASTER data for 2 October 2005 at 10:35pm, local time.

Source: Urban remote sensing for a fast-growing megacity: Delhi, India Netzband Maik and Atiqur Rahman

ENERGY INTENSITY OF URBAN FABRIC and UHI EFFECT

Source: (Memon, Leung, & LIU, 2007)

Controllable Variables

Urban Design and Structure related Population Related

Sky view Factor, Green Areas, Building Materials Anthropogenic heat, Air Pollution

UHI

Uncontrollable Variables

Anti-cyclone conditions, Season, Diurnal conditions, Wind

Speed, Cloud Cover

Scoping Study for Policy Initiatives to Minimize Urban Heat Island Effect for Low

Carbon Urban Growth

CAUSAL FACTORS OF UHI EFFECT

Building Building Building

Water percolation

Recharge of Ground Water

Building Building Building

Water percolation

Recharge of Ground Water

Building Building Building

Water percolation Reduction due to increase in hard surfaces

Building Building Building

Decreasing Ground water

Building

No Ground Water

Fully Air Conditioned! High Density Two Cars per Household

Vicious Cycle in full Steam !!

Water from Ganga

ENERGY INTENSITY OF URBAN FABRIC and UHI EFFECT

Compact

TREN

D

Incr

easi

ng

Ener

gy In

ten

sity

an

d U

HI

Dense Highrise

Building Building

Bengaluru Will be Unliveable in Five Years, Warns IISC Study

The IISC study claims that Bengaluru has witnessed an alarming growth of builtup area in the last 40 years.

The growth has been a phenomenal 525%. It also says that the vegetation of the once Green City

Bengaluru has seen a decline of 78%. The city also known as "Lake City" has lost 79% of its water bodies during the same period.

Vanishing lakes

A view Herohalli Lake. A view of Yelahanka lake

WATER SCARCITY

GLOBAL TEPERATURE RISE !

URBAN AIR AND NOISE POLLUTION

CITIZENS CONSCIENCE AND THE INFORMED CONSUMER