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MAXIMIZING ENERGY EFFICIENCY WITH CONCRETE’S THERMAL MASS

Rico Fung, P.Eng., LEED®AP Director, Markets & Technical Affairs CEMENT ASSOCIATION OF CANADA

LEARNING OBJECTIVES

Cement and concrete industry’s advances in

reducing its carbon footprint Concrete’s ability to reduce energy demands

in buildings Concrete’s broader contribution to

sustainability

WHAT WE WILL COVER TODAY Canada’s cement and concrete industry Why focus on energy efficiency Life cycle assessment for a holistic view of

energy use in buildings Concrete’s contribution to energy efficiency Real-world examples Concrete’s broader contribution to

sustainability

A LOOK AT CANADA’S CEMENT AND CONCRETE INDUSTRY

ABOUT CEMENT AND CONCRETE

Cement is A very fine, dry powder Manufactured and shipped

globally Sold in bulk or bags 7% - 11% of a concrete mix The glue that holds concrete

together

Concrete is Created by mixing cement,

aggregate (sand & gravel), water Produced locally, mixed and

hauled over short distances, typically less than 150 km from a project site

The 2nd most used substance on the planet, after water

THE CANADIAN CEMENT INDUSTRY

OUR COMMITMENT TO SUSTAINABILITY

Sustainability is a collective challenge that requires a collective solution.

OUR COMMITMENT TO SUSTAINABILITY

Our industry is committed to: Continuous investment in reducing our operational footprint

Reduced GHGs and Air Emissions Energy Efficiency Alternative and Renewable Fuels Quarry Management and rehabilitation Community Engagement

Being a proactive partner in driving a societal shift to a more sustainable economy Working collaboratively with governments, industry, environmental and civil society groups to identify sustainable solutions

The World Business Council for Sustainable Development Cement Sustainability Initiative

EXAMPLE: REDUCING OUR CARBON FOOTPRINT

We have reduced CO2 emissions per tonne of cement by about 10% in 10 years Improvements in operating energy efficiency Use of alternative and renewable energy sources Use of Supplementary Cementing Materials (SCMs)

Introduced a new cement that will reduce CO2 by a up to 10%

Produces concrete of equivalent strength to that produced with regular Portland cement

TOWARDS GREATER SUSTAINABILITY: FOCUS ON ENERGY EFFICIENCY

WHY FOCUS ON ENERGY EFFICIENCY

Concerns about global warming and climate

change have led to an unprecedented societal call to minimize energy demand and reduce CO2 emissions

WHY FOCUS ON ENERGY EFFICIENCY

From a business perspective, it reduces operating costs, improving the bottom line for building owners

Source: KPMG LLP, Climate Change: Risks & Opportunities in the Canadian Commercial Real Estate Market, 2009

BUILDINGS ARE A MAJOR SOURCE OF ENERGY CONSUMPTION

In 2009, buildings consumed 31% of all secondary energy use in Canada

Source: Natural Resources Canada, Office of Energy Efficiency, Energy Efficiency Trends in Canada 1990-2009

37%

30%

17%

14% 2%

Industrial Transportation Residential Commercial / Institutional Agricultural

BUILDINGS ARE A MAJOR SOURCE OF GHG EMISSIONS

Buildings generated 28% of all GHGs in Canada1 and these emissions are expected to grow by 8% by 20202

1. Natural Resources Canada, Office of Energy Efficiency, Energy Efficiency Trends in Canada 1990-2009 2. Environment Canada, Canada’s Emission Trends 2012

31%

38%

15%

13%

3%

Industrial Transportation Residential Commercial / Institutional Agricultural

THE NEED AND OPPORTUNITY TO MAXIMIZE ENERGY EFFICIENCY ARE GREATER THAN EVER

Nearly 75% of Canada’s buildings will be new or renovated by the year 2035

How expensive will energy be by then? Let’s do it right!

Source: RAIC 2030 Architecture Challenge

THE NEED AND OPPORTUNITY TO MAXIMIZE ENERGY EFFICIENCY ARE GREATER THAN EVER

Both RAIC and CaGBC have embraced the challenge

BUILDINGS LIFE CYCLE ASSESSMENT & EXAMPLES

PHASE 1 INITIAL ENERGY USE

Required to produce the building

PHASE 2 SERVICE LIFE ENERGY USE

Required to operate and maintain the building

PHASE 3 DECOMMISSIONING

ENERGY USE Required to dispose of

the building

Raw material extraction Manufacturing and

processing Transportation Construction

PRE-USE

Plug loads Lighting

HVAC systems Routine maintenance

USE

Demolition Transportation

Recycling/reuse Landfilling

END-OF-LIFE

TYPICAL PHASES AND COMPONENTS OF A BUILDING’S LIFE CYCLE

MIT LIFE CYCLE ASSESSMENT (LCA) STUDY

Single Family Multi-Family Commercial

U.S. Department of Energy benchmarked models of three building types Conventional construction with conventional heating and cooling systems EnergyPlus simulation program to model energy use, GaBi software for LCA

SINGLE FAMILY HOUSE LCA

0

1000

2000

3000

4000

5000

6000

Chicago ICF Chicago Wood Phoenix ICF Phoenix Wood

GW

P (k

g C

O2e

/m2 )

End-of-life Use Pre-use

Global Warming Potential Normalized by Gross Floor Area Over a 60-year Lifespan

MULTI-RESIDENTIAL BUILDING LCA

Global Warming Potential Normalized by Gross Floor Area Over a 60-year Lifespan

0

1000

2000

3000

4000

5000

6000

Chicago ICF Chicago Wood Phoenix ICF Phoenix Wood

GW

P (k

g C

O2e

/m2 )

End-of-life Use Pre-use

COMMERCIAL BUILDING LCA

Global Warming Potential Normalized by Gross Floor Area Over a 60-year Lifespan

0

1000

2000

3000

4000

5000

6000

Chicago Concrete Chicago Steel Phoenix Concrete Phoenix Steel

GW

P (k

g C

O2e

/m2 )

End-of-life Use Pre-use

MIT LCA STUDY - KEY TAKEAWAYS

Operating energy is the predominant component of a building’s total energy use

Initial embodied energy is a small component A concrete structure’s GWP is up to 8% lower

than a corresponding wood-frame structure, over a 60-year period, before considering the impact of energy reducing technologies

UBC LCA STUDY SUPPORTS MIT STUDY RESULTS

Comparative analysis of six-storey concrete and wood buildings in Vancouver with a 60 year service life

Conclusions Buildings’ environmental performance highly

dependant on energy use over their service life Concrete buildings required less energy over

their service life than wood buildings

CONCRETE’S CONTRIBUTION TO ENERGY EFFICIENCY

REDUCED INITIAL EMBODIED ENERGY

Initial Embodied Energy < 10% of Global Warming Potential (GWP)

THERMAL MASS MODERATES INDOOR CLIMATE

Acts as a heat sink, absorbing and storing heat gains during the day, and releasing heat back to interior space during the night

Reduces and delays peak load demands Helps reduce heating and cooling energy demands

Time Lag and Temperature Damping – from ASHRAE Standard 90.1

WHY? CONCRETE’S THERMAL MASS REDUCES OPERATING ENERGY USE

Concrete’s thermal mass

Thermal mass = ability of a material to store heat energy

Permits energy storage and regulation of interior temperature conditions

Maximizes the benefits from integrated energy saving technologies

Temperature moderation in a cave environment

NSW Department of Education and Training, Riverina Environmental Education Center

INNOVATIVE BUILDINGS SHOW EVEN BETTER RESULTS

Buildings where concrete’s thermal mass

was activated with smart energy systems and strategies achieved operating energy reductions of up to 70% when compared to conventional construction

STRATEGIES TO MAXIMIZE ENERGY EFFICIENCY

Designing “smart” buildings that respond to their external environments

Using integrated energy saving technologies and processes Geothermal heating and cooling systems, radiant

floors, hydronic heating, solar panels, etc. Maximizing buildings’ useful service life Build it once. Build it right. Build it to last.

Matching the building’s energy outlook to its design service life

CONCRETE’S THERMAL MASS BENEFITS KNOWN FOR CENTURIES

CLASSIC ADOBE BUILDINGS

http://travel.nationalgeographic.com/travel/world-heritage/pueblo-de-taos/

32

CLASSIC ADOBE BUILDINGS

Used by the indigenous peoples of the American southwest

High thermal mass from thick, rammed earth walls

In hot desert climates moderates the indoor environment from daily high and nightly low temperatures

33

THERMAL MASS MITIGATES THE EFFECTS OF SOLAR RADIATION ON THE BUILDING ENVELOPE

Dark tinted glass wall (Vancouver) Maximum measured surface temperature = 47∘C

Concrete wall (Vancouver) Maximum measured surface temperature = 35∘C

Specific Heat Capacity (Cp) – j/kg °K Heat storage capacity per kilogram of material

Density (ρ) – kg/m3

Mass per unit volume Thermal Conductivity – W/m °K The ease with which heat can travel through a material Moderate value is better for thermal mass effect

Thickness of the material (t)

THERMAL MASS EXPLAINED

0

500

1000

1500

2000

2500

3000

3500

4000

4500

Material

Water

Stone

Brick

Concrete

Clay Brick

Steel

Wood

HEAT CAPACITY OF BUILDING MATERIALS

Spe

cific

Hea

t Cap

acity

(J/k

g . K

)

0

5

10

15

20

25

30

35

40

45

50

Material

Water

Stone

Brick

Concrete

Clay Brick

Steel

Wood

Insulation

THERMAL CONDUCTIVITY

Ther

mal

Con

duct

ivity

(W/m

.K)

Crude Approximation of Thermal Mass (TM) TM = Cp x ρ x t Ignores Thermal Conductivity

Contributing Factors: Climate data, solar radiation, internal loads,

infiltration, ventilation and wind properties

Source: C.A. Balaras. (1996). The Role of Thermal Mass on the Cooling Load of Buildings. An Overview of Computational Methods. Energy and Buildings 24, pp. 1-10.

THERMAL MASS EXPLAINED

THERMAL MASS EXPLAINED (MIT)

For new construction, based on ASHRAE 90.1-2007, on a sliding scale: 12% improvement = 1 point 48% improvement = 19 points

(Measured over the baseline energy performance in accordance with ASHRAE 90.1 – 2007 Standard)

CONTRIBUTION TO LEED® 2009 - ENERGY AND ATMOSPHERE CREDIT POINTS

IN THE SUMMER HIGH THERMAL MASS BUILDINGS

tend take on the average outdoor temperature; cooler during the daytime hours

Less cooling capacity and cooling energy (Saving $$$)

Can push peak cooling needs well into the late afternoon and evening hours (Saving $$$)

more comfortable

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HOW ABOUT THE WINTER CONDITION?

Thermal mass moderates solar gains, avoids uncomfortable temperature swings during sunny periods

Can result in lower annual heating requirements

42

HOW MUCH CONCRETE IS NEEDED?

Not much! Just enough to hold the building up…

43

THE LESSON?

For the Heating Season: Start with an air-tight building envelope, and do

not over ventilate Thermal mass helps to moderate solar gains to

prevent overheating For the Cooling Season: Take advantage of free cooling when outdoor

conditions permit through natural or forced ventilation Limit solar gains!!!

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REAL-WORLD EXAMPLES OF MAXIMIZING ENERGY EFFICIENCY Institute for Computing, Information and

Cognitive Systems, University of British Columbia

Earth Rangers Centre Manitoba Hydro Place Del Ridge Homes Greenlife Condominium

Project

INSTITUTE FOR COMPUTING, INFORMATION & COGNITIVE SYSTEMS (ICICS), UBC

Institute for Computing,

Information and Cognitive Systems (ICICS)

Center for Integrated Computer Systems Research (CICSR)

ARCHITECT Hotson Baker (Now Design Dialog) and B+H ENGINEERS Stantec and Bush, Bohlman + Partners

ICICS ENERGY FEATURES Radiant slab heating and cooling Ventilation air distribution Extensive use of natural light Lighting sensors control use of artificial lights Ventilation heat recovery Radiant slab pipe distribution system

differentiated into core and perimeter systems Operable windows provide additional occupant

temperature regulation

0

100

200

300

400

500

600

700

800

Summer Fall Winter Spring Total

Equi

vale

nt k

Wh/

m2

ICICS CICRS

ICICS / CICRS COMPARATIVE ENERGY CONSUMPTION OVER A YEAR

Overall ICICS energy consumption ≈ 60% lower than CICRS 71% in summer and 48% in winter

ICICS ENERGY USE RESULTS

Energy intensity ≈ 60% lower than CICSR’s Energy savings of:

20% over national Model Energy Code for Buildings 60% over the 2005 Commercial and Institutional

Consumption of Energy Survey University results Additional optimization of systems would allow

further energy savings UBC has mandated Silver LEED certification for

subsequent projects

EARTH RANGERS CENTRE

ARCHITECT: Bautech Developments Ltd STRUCTURAL ENGINEER: Internorth Engineering Inc.

EARTH RANGERS CENTRE ENERGY INNOVATIONS

EARTH RANGERS CENTRE – EARTH TUBES

EARTH RANGERS CENTRE - RADIANT FLOORS

EARTH RANGERS CENTRE ENERGY SAVINGS

Improved energy efficiency by 10% per year

Earth Tubes produce savings of $7K per year

Additional concrete paid for itself within the first 5 years of operation

Currently LEED Platinum Existing Buildings: Operations and Maintenance

MANITOBA HYDRO PLACE

Reports energy savings of 70% compared to comparable office towers

Reports estimated energy savings of $500K annually

LEED Platinum Certified

“the concrete and thermal mass it

provides are fundamental to the building’s energy efficient design...”

Energy Use Monitoring Officer, Manitoba Hydro Place, June 2011

1

2

3

4

5

1

1 3 – 6 storey tall atria act as the building’s lungs

24m high waterfall either humidifies or dehumidifies the air depending on the season

Air is distributed via the raised floor distribution plenum

Exposed ceiling mass uses radiant heating and cooling

Geothermal system draws excess heat or cold stored within the soil to condition the building

Air flows to the solar chimney and is exhausted upward in the summer

Air is drawn down in winter and used to warm the parking garage

2

3

4

5

6

7

6

7

Image © Bryan Christie Design. Image courtesy of Kuwabara Payne McKenna Blumberg Architects

MANITOBA HYDRO PLACE AND RADIANT HEATING AND COOLING Exposed radiant

concrete ceiling slabs are primary source of heating and cooling

Reduces demand for forced air systems, which run at higher temperatures

Image courtesy of Kuwabara Payne McKenna Blumberg Architects

MANITOBA HYDRO PLACE AND DISPLACEMENT VENTILATION

Displacement ventilation delivers 100% fresh air

Stale air exits via North Atrium into solar chimney

Conventional ductwork and hung ceiling eliminated Operable

interior window

Computer controlled exterior window

Computer controlled louver blinds

Radiant ceiling slab

Column free space

Perimeter of edge slab

MANITOBA HYDRO PLACE AND CONCRETE’S THERMAL MASS

Image courtesy of Kuwabara Payne McKenna Blumberg Architects

MANITOBA HYDRO PLACE AND GEOTHERMAL HEATING AND COOLING

Includes 280 boreholes, six inches in diameter, 400 feet deep

Provides cooling in the summer and meets 60% of heating demands in winter

Image © Bryan Christie Design. Image courtesy of Kuwabara Payne McKenna Blumberg Architects

DEL RIDGE HOMES GREENLIFE CONDOMINIUM PROJECT, MILTON, ONTARIO

Keith Loffler McAlpine Architects

DEL RIDGE HOMES ENERGY SAVINGS

Operational energy per suite: 4.1 kwh/sf/year − about 20% of the norm

Insulated Concrete Form wall construction Thermal mass moderates hallway and stairwell

temperatures Eliminates the need for 20 - 2.5 kw heaters

Installation of R70 EPS on roof area improves energy efficiency

Enclosed garage ramp saves 70,000 kwh/yr

DEL RIDGE HOMES ENERGY SAVINGS

Solar powered parking lights save about

45,000 kwh/year Motion sensoring in parking stalls and other

common areas reduced demand by about 85% Make up air is tempered by a geo-thermal

“multi-stack” unit

CONCRETE’S THERMAL MASS MAKES IT POSSIBLE TO MINIMIZE ENERGY DEMAND THROUGHOUT A BUILDING’S LIFE CYCLE, REDUCING COST OF OWNERSHIP AND CO2 EMISSIONS

CONCRETE’S BROADER CONTRIBUTION TO SUSTAINABILITY

CONCRETE’S SUSTAINABILITY ATTRIBUTES Durability Resiliency Energy efficiency Versatility 100% Recyclable Produced locally

CONCRETE’S SUSTAINABILITY BENEFITS Maximizes buildings’ service life Allows greater, safer urban density Reduces operating costs and CO2 emissions Offers limitless architectural possibilities Benefits local economies

TODAY’S CONCRETE IS ESSENTIAL TO BUILDING SMART, SAFE, ENERGY-EFFICIENT, SUSTAINABLE COMMMUNITIES

THANK YOU!