integrating curtain speaker wall systems into principal ... presentation 2014_curtain wall_may 8,...

5/13/2014

1

Integrating Curtain

Wall Systems into

Facades

Dave André, P.Eng

Principal,

Building Science Specialist

The challenges of “green”

buildings

Speaker

• Principal, Building Science Specialist

• Practice lead in GTHA for façade

engineering and building envelope energy

performance

Expectations of

Building Envelope

• Cost Effective

• Durable

• Low Maintenance

• Environmental Separation (Heat, Moisture, Air)

• Energy Efficient “Green”

• Beautiful

Challenge

• Increasing Energy Codes

• Curtain Wall = Low R-Value

I want everything in one bag!

…but I don’t want it to be heavy.

5/13/2014

2

Presentation Outline

The Basics of Curtain Wall Systems1

Energy Code Requirement2

BE Energy Optimization3

Predicting Performance4

Case Study5

Best Practice6

The Basics of Curtain Wall Systems1

Basics of Curtain WallsBasics of Curtain Walls:

Types

Window Wall

5/13/2014

3

Basics of Curtain Walls:

Glazing Method

• Structural Silicon (2SSG or 4SSG)

– A: Exterior weatherseal

– C: Glazing unit

– E: Structural silicone –common position for 4SSG


Glazing Method


Glazing Method

De-glazing

Sealant

• Exterior Batten (Captured)

– A: Exterior snap

– C: Pressure plate

– E: Glazing unit

– H: Thermal break

– J: Glazing cavity


Glazing Method

5/13/2014

4


Glazing Method

Pressure plate

Drainage

Corner block


Drainage Types

• Face Sealed

– Totally reliant on sealants

– No water collection or drainage

• Rain Screen

– Tolerant water penetrating exterior surfaces

– Provisions to collect and drain water

Energy Code Requirements2

2012 Ontario Building Code

Part 12 Resource Conservation

Section 12.1. General

12.1.1. Application

12.1.1.1. Scope

(1) The scope of this Part shall be as described in Subsection

1.1.2. of Division A.

12.1.1.2. Application

(1) This Part applies to resource conservation in the design and

construction of buildings.

5/13/2014

5

Part 12 Resource Conservation

Section 12.2. Energy Efficiency

12.2.1.1. Energy Efficiency Design Before January 1, 2017

(1) This Article applies to construction for which a permit has

been applied for before January 1, 2017.

(2) Except as provided in Sentences (3) and (4), the energy

efficiency of all buildings shall conform to Division 1 and

Division 2 or 4 of MMAH Supplementary Standard SB-10,

“Energy Efficiency Requirements”

18

Foreword

“The application of the above documents to existing

buildings is limited to the scope of Part 10 and Part 11

of the Code.”

Supplementary Standard SB-10

Energy Efficiency Supplement

July 1, 2011 update

19

The energy efficiency design of buildings is

required to meet one of the following three

requirements:

1. Achieve the energy efficiency levels attained

by conforming to the ANSI/ASHRAE/IESNA

90.1, as modified by Chapter 2 of this Division.

2. Exceed by not less than 5% the energy

efficiency levels attained by conforming to the

ANSI/ASHRAE/IESNA 90.1, or

3. Exceed by not less than 25% the energy

efficiency levels attained by conforming to the

CCBFC, “Model National Energy Code for

Buildings.”

Compliance Options

5/13/2014

6

21

Prescriptive Path – Climate Zones

22

ZONE 5:

� Toronto, Windsor

Hamilton

ZONE 6:

� Ottawa, Kingston

Kitchener, Waterloo,

London

R2.9

Current Design Trends

5/13/2014

7

Performance Path)

• Supplementary Standard SB-10

• 5% more energy efficient

ASHRAE 90.1 2010 or

• 25% more energy efficient than

MNECB 1997

40-Storey High rise Condo in Toronto

Envelope:

� Window Wall Construction

� Glass Spandrel Panels,

Mineral Wool in backpan (R=5.3)

� 70% Window-to-Wall Ratio

Mechanical:

� Four-Pipe Fan Coil system

� Forced-draft, 80% efficiency boiler and

Mid-Efficiency Chiller

� Corridor fed ventilation

Base Design

End-Use Design (GJ) MNECB Reference (GJ) % Savings

Lighting 2,799 2,886 3.0 %

Receptacles 1,376 1,372 -0.3 %

Heating 15,539 12,585 -23.4 %

Cooling 1,542 1,220 -26.4 %

Pumps 1,923 2,342 17.9 %

Fans 1,545 2,332 33.8 %

DHW 5,163 5,014 -3.0 %

Exterior Lighting 38 38 0.0 %

Elevators 900 900 0.0 %

% Savings Relative to MNECB -7.4%

With no energy efficiency upgrades …

5/13/2014

8

Improved Design

With some basic energy efficiency upgrades …

� Variable speed pumps

� 5% reduction to window-to-wall ratio (WWR)

� Mid-efficiency domestic hot water plant

� Assumed 15% reduction in hot water w/

low-flow fixtures

� High-efficiency condensing boiler

� Addition of occupancy sensors to underground

parking garage lighting


End-Use Design (GJ) MNECB Reference (GJ) % Savings

Lighting 2,649 2,886 8.2 %

Receptacles 1,376 1,372 -0.3 %

Heating 9,122 12,585 27.5 %

Cooling 1,524 1,220 -24.9 %

Pumps 1,617 2,342 31.0 %

Fans 1,814 2,332 22.2 %

DHW 3,869 5,014 22.8 %

Exterior Lighting 38 38 0.0 %

Elevators 900 900 0.0 %

% Savings Relative to MNECB 20.1 %


� Could achieve 25% threshold with individual suite ERV’s

(becoming common in high-rise MURBs targeting LEED)

� With conservative in-suite heat recovery = around 26%

better than MNECB

32

PART 12 - RESOURCE CONSERVATION AND ENVIRONMENTAL INTEGRITY

12.2.1.2. Energy Efficiency Design After December 31, 2016

(2)Except as provided in Sentences (3) and (4), the energy efficiency of all buildings

shall,

(a)be designed to exceed by not less than 13% the energy efficiency levels required

by Sentence 12.2.1.1.(2), or

(b) conform to Division 1 and Division 3 or 5 of MMAH Supplementary Standard

SB-10, “Energy Efficiency Requirements”.

(3)Except as provided in Sentence (4), the energy efficiency of a building or part of a

building of residential occupancy that is within the scope of Part 9 and is intended for

occupancy on a continuing basis during the winter months shall,

(a) be designed to exceed by not less than 15% the energy efficiency levels required


(b) conform to Chapters 1 and 3 of MMAH Supplementary Standard SB-12, “Energy

Efficiency for Housing”.

SB-10 AFTER 2016

5/13/2014

9

33

PART 12 - RESOURCE CONSERVATION AND ENVIRONMENTAL INTEGRITY

12.2.1.2. Energy Efficiency Design After December 31, 2016

(2)Except as provided in Sentences (3) and (4), the energy efficiency of all buildings

shall,

(a)be designed to exceed by not less than 13% the energy efficiency levels required


(b) conform to Division 1 and Division 3 or 5 of MMAH Supplementary Standard

SB-10, “Energy Efficiency Requirements”.

(3)Except as provided in Sentence (4), the energy efficiency of a building or part of a

building of residential occupancy that is within the scope of Part 9 and is intended for

occupancy on a continuing basis during the winter months shall,

(a) be designed to exceed by not less than 15% the energy efficiency levels required


(b) conform to Chapters 1 and 3 of MMAH Supplementary Standard SB-12, “Energy

Efficiency for Housing”.

SB-10 AFTER 2016

25% 25%

~34%

~65%

2014 2016 2017 20??

Energy Efficiency (above MNECB 1997)

SB10

Sustainability Standards Raise the Bar

• LEED for New Construction and Major Renovation

• Energy and Atmosphere Prerequisite No. 2:

• Demonstrate 10% improvement

EA Credit 1 (EAc1): Optimize Energy

Performance:

• EA Credit (EAc1): Optimize Energy

Performance

• Whole building energy simulation:

1 to 19 points for 12% to 48%

improvement

5/13/2014

10

BE Energy Optimization3

BE Energy Optimization BE Energy Optimization

Step 1: Identify Options

Step 2: Cost / Benefit Analysis

5/13/2014

11

Improved Frames

Images from FM Graham website

Fiberglass Frame

42

Image from Fassaden website

Wooden Frame

Alternate Glazing - VIG

• 2 plies of 3 mm (1/8 in.) clear glass

• 0.7 mm (0.03 in.) dia. pillars

spaced on 25 mm (1 in.) centers

• Hard vacuum is sealed in the gap

• Low melting temperature solder

glass around the edges.

• Result: glass less than 7 mm

(9/32 in.)

5/13/2014

12

Alternative Approaches - Insulating

Vacuum Insulated Panels

Alternative Approaches

Vacuum Insulated Panels

Alternate Glazing – Dynamic Glass

Image from ClearStream Architectural Glass

5/13/2014

13

Image from ClearStream Architectural Glass

Dynamic Glass

Typical IGU

Electronically Tintable Glass as an Architectural Enabler

Helen Sanders, PhD and Louis Podbelski, AIA.





5/13/2014

14

Alternative Approaches - LDG

Light Diffusing Glass

• Integrated fiber optics inside IGU

• Light refracted by fiber optics

• Reduces glare and concentrated solar gain

Images from Schott Glass website

Images from ClearStream Architectural Glass

Before

After

Translucent Daylight SystemImage from Kalwall website

Alternative Approaches –

Daylight Control

Light Shelf

Power Shading

5/13/2014

15

Predicting Performance4

ASHRAE Research ProjectDetails Catalogue

40 building assemblies and details common to

North American construction

Focus on opaque assemblies, but also includes

some glazing transitions

Details not already addressed in ASHRAE

publications

Highest priority on details with thermal bridges

in 3D

Overall Heat LossTypes of Transmittances

Clear Field Linear Point

oQ oroU Ψ χ

5/13/2014

16

3D Modelling

• ASHRAE 1365-RP (40)

• Insulated Metal Panels (20)

• Cladding attachments (20)

• VIP Spandrel (35)

• Aerogel (5)

• EIFS (12)

• Manufactured Thermal Breaks(8)

We have more than doubled the catalogue

Case Study5

Cost Benefit Analysis

Original Design:

• Window Wall east and

west

• Curtain wall north face

• Some Insulated metal

panel (most of south wall)

• 62% WWR (vision ratio)

• Conventional concrete

balcony floor slabs

• Commercial first level

What is the effective R-value?

5/13/2014

17

Reference Building PerformanceHeat Flow (BTU/°F) = Transmittance (Btu / hr ft² °F) * Area (ft²)

Calculated for Clear Wall and Vision Elements

Total Transmittance (Btu / hr ft² °F) = Total Heat Flow (BTU/°F) /

Total Area (ft²)

Thermal Performance

OVERALL RESULTS SUMMARY

Total Wall Heat Flow 47,076 100.0% Total Wall Heat Flow

Bldg U-Value

(BTU/sqft °F)

Effective Bldg R-value

(sqft °F/BTU)

Scenario 1 - Modified Baseline w/ 62% vision ratio

0.382

2.62

OVERALL RESULTS SUMMARY

Total Wall Heat Flow 47,076 100.0% Total Wall Heat Flow

Bldg U-Value

(BTU/sqft °F)

Effective Bldg R-value

(sqft °F/BTU)

Scenario 1 - Modified Baseline w/ 62% vision ratio

0.382

2.62

5/13/2014

18

Opaque

27%

Vision

73%

62% Vision Ratio

-9.5%

Opaque

27%

Vision

73%

62% Vision Ratio

Opaque

31%

Vision

69%

55% Vision Ratio

Opaque

40%

Vision

60%

45% Vision Ratio

Some things to try:

� SPUF in spandrels

� VIP’s in spandrels

� Triple Glazing

� Thermally broken balconies

� Better metal panel systems

� Combinations of above

5/13/2014

19

Vision

RatioScenarios

Reduction in

energy from

Baseline (%)

Rvalue

Preliminary Total

Annual Energy

Cost

Cost

Difference

from

Baseline

Initial

Installed

Cost

Pay

back

(yrs)

49% Baseline 9.5% 3.5 $ 452,809 $ 6,497 0

55% w/ 2" SPUF in spandrels 11.2% 5.7 $ 441,973 $ 13,187 $ 150,000 11.4

55%w/ 2" SPUF + MSTB

balconies13.5% 6.5 $ 439,233 $ 15,928 $ 624,000 39.2

55%

Triple IGU CW + 2" SPUF

+ good metal panel +

MSTB balconies

26.2% 6.9 $ 429,917 $ 25,243 $ 1,284,498 50.9

49% w/ VIP spandrels 19.8% 6.6 $ 430,268 $ 22,541 $ 1,549,440 68.7

49%w/ 2" SPUF + MSTB

balconies16.9% 6.8 $ 429,443 $ 23,366 $ 624,000 26.7

49%w/ 2" SPUF + Triple

glazed CW IGU22.8% 6.1 $ 425,882 $ 26,927 $790,000 29.3

49%

Triple IGU CW + 2" SPUF

+ good metal panel +

MSTB balconies

26.5% 7.2 $ 421,955 $ 30,854 $ 1,284,498 41.6

Solutions:

• Reduce WWR to 49%

• Spray foam spandrels

• Improve thermal performance of other claddings

• Manufactured Structural Thermal Breaks (MSTB) or

Triple Glazing at Curtain Wall

Best Practice6

76

• Vision AreaReduce

• Double low e glass

• Substitute vision areas (skylights)

• Spray foam backside of spandrelImprove

• Thermal bridging losses (slab edges, window transition, etc.)Modify

• Dynamic glass

• Vacuum insulated panel

• Triple glazingInvest

BE Thermal Optimization:

Roadmap

5/13/2014

20

77

� Shift from wall R-value thinking to

whole building R-value

� Look to building envelope to

achieve energy gains

� Plan by defining options early and

analyzing

� Be prepared to evaluate new

products

CURTAIN WALL BEST PRACTICE Accessing Information

http://www.morrisonhershfield.com/

ashrae1365research/Pages/Insights-Publications.aspx

Thank You

integrating curtain speaker wall systems into principal ... presentation 2014_curtain wall_may 8,...

Documents