Energy Efficient Green Building Materials

SHRIRAM INSTITUTE FOR INDUSTRIAL RESEARCH

19, UNIVERSITY ROAD, DELHI – 110 007

Presented By: Dr. R. K. Khandal

OUTLINE

Green: •Definition • Origin • Design • Material

• Attributes • Criteria • Examples

Green Buildings : • Properties • Components

Scope of Nanomaterials : • Defining • Dimensions• Domain • Process

Solar Spectrum

Novel Materials

What is Green?

Light

Hope

Darkness

Sorrow

ClarityHazy

Growth

ProgressStagnant

Decay

GREY

Undesirable Desirable

SCENARIO

GREEN

What is Green Design?

Variable Intensiveness & Extensiveness

This needs to be replicated while designing a green building

• Intensity• Coverage• Direction

Greenest Material ?

Greenest Material

TREE

Greenest Shelter

To create materials with green properties is a challenge!

Sunlight

Origin of the word ‘Green’

Green building is one which is sustainable, like plants!

Natural resources

CO2

INPUT OUTPUT

Energy

Food

Biodiversity

Shelter

O2

Green : Attributes

Materials possessing the basic characteristics akin to the mechanism in plants can be termed as green

Reduce energy consumption natural habitat depletion

pollution water consumption Recycling & Reuse is possible

Renewable

Withstands all weather conditions

No burden on environment

Utilizes natural resources in a sustainable manner

In sync with the natural cycle

Energy balance (C footprint)

Unending Production cycle (lifecycle)

Balances Climate

Integral part of system that supports life

Cleanses & scavenges environment pollutants

Carbon-sink

Preserves the ecology

Feature GreennessSignificance

Green Materials: Features for Greenness

Renewable

Synthetic

Sustainable

Depleting

Energy intensive

Alternative

Bioroute

C- emission

Low C-emission

No C-emission

Durable

Recyclable

Reusable

Energy-Efficient

Env.-friendly

Sustainable

There are many ways to obtain green materials from various raw materials.

Greenness is derived from the overall emissions of carbon; Carbon-footprints.

Raw Materials

Processing

Materials

Low

High

Low

High

Medium

Low

High

Medium

Input Criteria

Green Materials: Criteria

Source of raw materialProcessingEnergyWaste

RenewableEfficientConservationMinimum

Output

Effect

PerformanceDurability

Disposal

Waste reduction

Cradle-to-grave

Safe

Long – lastingSafety

Life – Cycle

ReusabilityDegradability

Non-hazardous degradation products

Recyclability

Green Buildings : Criteria

Weathering

Mechanical

Light

Heat

Green Materials & green buildings should be self sustainable.

ConditionTemperature Dimension

Effect Criteria

Rains

Environment Pollution

Fire

Operational Activities

IlluminationHeating

DimensionStructureDecayErosion

AestheticsHygieneHealth

Destruction

EmissionsPollution

TransferConserveRetainTransmitReflectConversionStrengthLifecycle

StabilityLongevity

Rain- proof

Dust-proofSound proofInsect proof

Absorption

Fire-proofFlame-proof

Self-ventilation

Process GreennessFeature

Green Materials: Certain Examples

Cutting Shaping Polishing

Low Energy High

Soil preparation Casting Drying

Firing

Stone

Unburnt bricks

Burnt Clay bricks

Low

High

Materials

Flyash brick

Cement block

Low Energy

High Energy

Low Energy

High

Casting

Cement manufacture CastingCuring High Energy Low

Being energy-efficient and durable, make the energy-intensive materials relatively greener.

Green Buildings : Properties

Windows

Low emissivity

Switchability

Selectivity

Thermal resistance

Properties Requirements

Transmit solar energy & reflect IR energy in winter

Reject solar energy & heat in summer

Electrochromic Photochromic Thermochromic

Spectrally selective IR reflective

High R values > 18.3-44.1 (m/K)/W Low thermal conductivity

Transmission Visible Transmittance in all mode

Insulation

Shading Devices

Roofing

Windows & Doors

Skylights

•Cellulose insulation•Silicate foam

•Fire resistance•Light coloured

•Mineral wool•Cotton & fiber glass

•Light weight•Reflect IR rays

•Double glass•Low emissivity

•Gas filled windows•Electrochromic

•Maximize the use of natural light

•Sunshades•Canopies

•Landscape elements•Trees

By selecting green building materials, a healthier & more efficient environment can be created!

Energy Efficient Building Components

Energy Efficient Nanomaterials

Scope: Defining Nanomaterials

For a given volume of nanomaterial :

Surface area Thickness

More atoms at surface Extraordinary activity

Multi-phase systems Liquid : Liquid Solid : Liquid

Gas : Solid Gas : Liquid

Concept

Materials with particles of nanometer size

Volume = Surface area x thickness

Dimensions

Surfaces and interfaces of different phases at nano scale

Scope:Dimensions of Nano

What Happens Dimensions

Particle size More from less

Surface area Enhanced coverage

Activity Novel products

Efficiency Improved performanceper unit mass

Maximum possible benefits from minimum possible inputs

Effecting changes through and at atomic scale

SCOPE : DOMAIN

Keywords Domain

Particle size Distribution in the continuous phase

Modification of surfaces Interfacial tension

Surfaces Interfaces

Rising volume fraction Homogeneity of phases

of dispersing phase Domain of Nanotechnology: Multi-phase systems Liquid : Liquid Solid : Liquid

Surfaces and interfaces involving different phases

Gas : Liquid

Gas : Solid

Systems Process

Emulsion Macro Micro

Dispersion Coarse Fine

Solution Colloid

SCOPE: PROCESS

A process to create a continuous dispersed phase as fine as possible for homogeneity with the dispersing phase

(Liquid / Liquid; Gas/Liquid)

(Solid / Liquid)

(Solid / Liquid; Liquid/Liquid)Solubilization

NANOSCIENCE TO NANOTECHNOLOGY “MACRO TO NANO”

MATERIALS

Copper

Macro

PROPERTIES

Nano

Opaque Transparent

Platinum Catalyst

Aluminium Stable Combustible

Inert

Gold Inert Catalyst

Unique properties at the nanoscale are the driving force for exploitation of nanomaterials

Novel MaterialsSpectrally Selective MaterialsSelf-cleaning MaterialsPorous Materials

SOLAR SPECTRUM

Visible light (43%)

X-rays Micro wave

Radio wave

Infra red radiation (54%)

UV (3%)

Long Wavelength

1012

nm106 nm

700 nm

Chemical changes : Bond Dissociation Bond Formation Rearrangement Electron transfer

The energy of electron 1.23 eV 1000nm; thus, energies corresponding to < 1000nm can bring about chemical changes.

The region from 200nm to 1000nm is most useful for photochemical conversion.

Lu

x

400 nm 109 nm 1014 nmWavelength,Short Wavelength

200 nm

PHOTOCHEMICAL CONVERSION : MECHANISMThe Energy E of single photon is given by the Planck equation:-

E= h = hc/

Sun light

.

…….. ...………………………………electron

Excitation photon

excited state

Non-radiative relaxation

Conduction band

Valence band

h+

e-

Band gap

E=h

Every photochemical conversion process requires as an initial steps the absorption of photon energy and conversion into the internal energy of the first excited state of the molecule of the material

=Number of eventsNumber of photons absorbed

Green Materials: Spectrally Selective Materials

Thin film coatings based on the unique properties of spectrally selective materials are coated onto building components for conservation of energy and reduced energy consumption.

Admit light,

reject solar heat

Criteria

Transmit: 400 to 700nmReflect: > 700 nm

Requirement Design Materials

Solar heating

Radiativecooling

Transmit /absorb: <2500nm

Reflect : >2500nm

Emit : >5000nm

TiO2 Bi2O3 Zn/ Cu, Ag, Au/TiO2 Bi2O3

Al2O3 / MO/ Al2O3

SiO2;oxynitrides

Dielectric/ Metal/

Dielectric layer

Cermet Coating

Oxides

Semiconductor

Solar active (UV, visible & I.R.) materials can be designed by modifying the inherent band gap energy of materials by doping, ion impregnation etc.

6.3 eV 3.15 eV 1.58 eV

U.V

200 nm 400 nm 800 nm

Visible

TiO2

ZnO

CdSWO3

Band gap Energy

EMS()

TiO2 = 3.20 eV

ZnO = 3.35 eV

WO3 = 2.80 eV

CdS = 2.42 eV

Green Materials: Self Cleaning Materials

Density (Mg/m3)

Foams

Natural materials

Polymer nano- composites

Polymers

Metals

Metallic nanocomposites

Nanocrystalline metals

Ceramics

Standard composites

Nanotubes & fibers

You

ng’

s M

odu

lus

(GP

a)

Elastomers

Ceramic nanocomposites

0. 1 1.0 10

10-4

1

10

100

10-3

1000

Mechanical Properties: Smart Materials (Nano)

Distribution of pores within the material; presence voids results in material with relatively low densities.

Green Materials : Porous Materials

Polymers & Ceramics are the upcoming thermal insulating materials

Por

osit

y (%

)

50

0

100

Mesoporous materials

Xerogels

Porous glassesCeramic filters

Membranes

Ceramic honey combs

Ceramic foams

1Å 1nm 10nm 0.1µm 1µm 100µm10µm 1mm 10mm

Zeolites activated carbons

Dust collectors Ligh

t-weigh

t engin

eering

materials; in

sulators

Green Materials : Nanoengineered Concrete

Nanosilica

Precipitated Silica

Silica fume

MetakaolinFinely ground

mineral additivesPortland cement

Fly ash

Aggregate fines

Natural sand

Coarse aggregates

Nano engineered concreteHigh strength/ high

performance concrete

Conventional concrete

100 101 102 103 104 105 106 108107

10-1

10-2

100

101

102

103

104

105

106

Particle size(nm)

Sp

ecif

ic S

urf

ace

Are

a(K

g/m

2)

Nanoparticles allow better void filling & positive filler effects & improved bond between pastes aggregates; nanosized additives increase strength beyond what is attained with conventional materials

THANK YOU