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Reducing Energy Consumption & Improving Indoor Environmental Quality through Dynamic Shading Uma Patwardhan – MS in Sustainable Design – August 2012

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TABLE OF CONTENTS 1. Topic Justification 2. Case studies & Commercially Available Products 3. Health & Productivity Benefits 4. Hypotheses 5. Scope of work 6. Field experiments 7. Controls Decision flow chart

8. Simulation & Energy Savings 9. Triple Bottom Line calculations 10. Conclusion

11. Future Research

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WHY OFFICES ..... According to 2003 Commercial Buildings Energy Consumption Survey (CBECS): • 4,859,000 total commercial buildings in USA • 19% of total energy consumed by commercial sector • 57% energy consumed in heating, cooling and lighting in commercial buildings. • 30% of commercial buildings are offices comprising 33% of total floor space • 33% of total energy in commercial sector consumed in office buildings

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Indoor Environmental Quality Issues Images Source : Google Images

RADIANT TEMPERATURES

LIGHTING LOADS

GLARE

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Dynamic facades can help reduce energy loads and improve occupant comfort

Image Source : www.lowenergyfacades.gov (LBNL)

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SUCCESSFUL INSTALLATIONS % reduction in energy consumption represents reduction due to all sustainable design solutions including solar shading devices Project Name

Terry Thomas

SBL Offices

Alley 24

Bank of America

LOTT Clean Water Alliance

Heifer International Headquarters

Manitoba Hydro

Interserve

Function

Commercial

Commercial

Mixed Use (Retail, Office, Residential)

Commercial

Commercial

Commercial

Commercial

Commercial

Location

Seattle, WA

Linz, Austria

Seattle, WA

New York

Olympia, WA

Little Rock, AR

Winnipeg, Canada

Leicester, England

KPMB Architects

CPMG Architects

Architect

Weber Thompson

Helmut Schimek, Linzli

NBBJ

Cook +Fox

Miller Hull Patnership LLC

Polk Stanley Rowland Curzon Porter Architects, Ltd

LEED GOLD for core and shell and LEED PLATINUM for commercial interiors

NA

LEED Silver

LEED Platinum

COTE Award

LEED Platinum

LEED Gold

Passivhaus accredition

5" & 3" Louvers

Sun shades & Light shelves

Venetian blinds

3" Motorized Venetian Blinds

View

Recognition

Type of Solar Shading Device

2" Chained & 4" Motorized Motorized venetian Venetian Blinds Blinds with sun with Sun Tracking tracking

Automated louvers

Louvers

Position (Interior / Exterior )

Interior + Exterior

Exterior

Exterior

Interior

Interior + Exterior

Interior + Exterior

Interior + Exterior

Exterior

Manufacturer

NA

Colt

Nysan, Hunter Douglas

Nysan, Hunter Douglas

Nysan, Hunter Douglas

Kawneer

Nysan, Hunter Douglas

Levolux

Special features

Operable windows along with automated louvers

PV cells on louvers

NA

Motorized or manual

NA

NA

Daylight blinds perforated

NA

% reduction in energy consumption

30%

40%

49%

50%

50%

52%

65%

Upto 90%

Data & Image Source

Weber Thompson

Colt

Hunter Douglas

Hunter Douglas

Hunter Douglas

Kawneer

Hunter Douglas

Levolux

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ENERGY, HEALTH & PRODUCTIVITY BENEFITS

In 2001 simulation study by Carbonari et al identify 8.6% annual energy savings due to application of adjustable louvers as compared to fixed louvers or no shading devices to south façade in moderate climate. They also identify 12.5% - 20.8% reduced energy consumption for buildings with southern orientation in climate that demands both heating and cooling .

In 1990 building case study in California, Benton & Fountain identified 50% savings in annual lighting, cooling and ventilation energy consumption and 15% reduced absenteeism with daylighting design which integrates layout, orientation, window placement, type of glazing, light shelves and ceiling.

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HIGH PERFORMANCE PRODUCTS Performance Criteria

Manufacturer Materials

1

Type

2

Location

3

Application

4

Fixed Adjustable / Dynamic (Manual, Automatic, Sensors, Timer, Computer) Interior (I) Exterior (EX) New Construction Retrofit Both

Additional Strategies required / Special Features

7 8 9 10 11

Aluminum

P P P

Satisfaction

P

Maintenance factor Ease of installation / operation Cost ($) Payback period (years)

Hunter Douglas Aluminum, Steel, Wood P P

Speciality Louvers

Bright Shelf

Retrolux U

RetroFlex

Retrolux A

Specialist Venetian Blinds

InLighten Light Shelf

Hunter Douglas

Hunter Douglas

Hunter Douglas

Retro Solar

Retro Solar

Retro Solar

Levolux

Kawneer

Steel

Wood, Glass, Metal

Aluminum

Aluminum

Aluminum

Aluminum

Aluminum

Aluminum

P

P

P

P

P

P

P P

P P

P

P

P

P

P

Concave up shape helps light redirection

Reflects most of solar incidence back before admitting light indoor

Dynamic Louvers Brise Soleil

Hunter Douglas Aluminum, Wood, Glass P

P

P

P P

P P P

P P P

P P

P

P

P

Perforated slats to permit view even when closed P P P P

Quality of light / glare - no glare

Aerofoil Louvers

P

Day Lighting / Light redirection Glare Reduction Solar Gain Control Access to nature when fully closed (% of view) Indoor Temperature Control Occupant

5 Results achieved 6

Interior MakroBlind Louvered Shade Hunter Douglas

Permits view Highly while reflecting reflective maximum solar mirrored finish incidence back preventing glare P P P

P P

P P 100%

P P

P

P P

P

P P

P P P P P

P

P

P

P

P P

P P P P

Effortless tilting for cleaning

P P P

P P 100% P Easy

P

P

Note : This is not an exhaustive list of products available commercially today, nationally and internationally. Similar type of products are available with various manufacturers with slight difference in specifications.

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HYPOTHESES Blinds with dynamic control (different slats positions as per orientation, seasonal & daily variation) 1. Reduces operative temperatures and radiant surface asymmetry thus reducing energy loads

2. Acts as dynamic insulating layer to faรงade 3. Prevents glare while maintaining the desired daylight levels even on cloudy days thus reducing lighting loads 4. Provides access to view 5. Improves occupant health and productivity by providing thermal and visual comfort 9


SCOPE OF WORK 1. Case Study : To identify energy efficient projects 2. Online market survey : To identify high performance commercially available products 3. Field experiments and Energy Plus simulation : To quantify energy loads reduction due to blinds deployment 4. Literature review : To identify occupant health and productivity benefits with shading strategy 5. Triple Bottom Line calculations 6. LEED credits 10


FIELD EXPERIMENTS 11


EXPERIMENTS LOCATION

Image Source : Google Images

12 Center for Building Performance & Diagnostics, CMU


Equipment & Sensors 1. 2. 3. 4.

1

2

3

4

Black Globe Thermometer HOBO Sensor Nikon Coolpix, Fish Eye lens Thermographic Camera

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Experiments Summary SOUTH EAST & SOUTH WEST BAY EXPERIMENTS Blinds Open vs Blinds Closed – Sunny Warm Blinds Open vs Blinds Horizontal (0°) Blinds Open vs Blinds 45° Blinds Closed vs Blinds Horizontal (0°) – Cloudy Hot Day Blinds Closed vs Blinds 45° Blinds Horizontal (0°) vs Blinds 45° - Partly Sunny Hot Day

WEST BAYS SIDE BY SIDE EXPERIMENTS Blinds Open (Control) vs Blinds Closed Blinds Open (Control) vs Blinds Horizontal (0°) Blinds Open (Control) vs Blinds 45° Blinds Closed (Control) vs Blinds Horizontal (0°)

Blinds Closed (Control) vs Blinds 45° Blinds Horizontal 0° (Control) vs Blinds 45°

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Methodology for Field Experiments •

Calibrated the HOBO sensors by keeping them next to each other on sunny and cloudy days and comparing the readings

In South bays, conducted experiments with blinds open and close to calibrate the two bays but found that the readings were different due to the influence of East and West and therefore side by side experiments were not possible.

Conducted experiments in South East and South West bays with blinds slats in different positions for seven days each. To normalize the data, identified days with similar outdoor conditions with respect to outdoor temperature and solar radiation and compared the effects of different blinds positions

Since these experiments were conducted during Swing season, finding comparable days was difficult. So, the experiment setup was moved to West bays where side by side experiments were conducted

Thermographic camera was used to analyze the surface radiant temperatures with the blinds intervention

Results from the field experiment were used in simulation to achieve percentage energy savings 15


Limitations •

Tests done in existing building with existing installations

Open plan office with partitions not upto the ceiling allows heat dispersion between adjoining bays

Unequal number and different types of blinds installed internally as well as externally. Difficult to quantify the impact of a specific type and location

Clerestory has light redirection devices allowing daylight penetration even with other blinds closed.

External louvers always closed thus blocking a considerable amount of direct solar incidence on glazing

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South Test Bays

SOUTH EAST

SOUTH WEST 17


BLINDS OPEN VS BLINDS CLOSED SOUTH EAST •

Blinds Closed maintain up to 2°F lower ambient temperature with no peak at morning and 8°F lower radiant temperature

Daylight levels sustained at 100 – 150 lux with blinds closed

Upto 3°F free cooling at night with blinds open

Blinds Closed maintain 8°F lower radiant temperature with no peak in afternoon

Daylight levels sustained at 150 – 300 lux with blinds closed

Upto 3°F free cooling at night with blinds open

SOUTH WEST

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BLINDS HORIZONTAL (0°) VS BLINDS 45° SOUTH EAST

Blinds 45° maintain 1° - 2°F lower ambient temperature with no peak at morning and 6°F lower radiant temperature

Daylight levels sustained at 200 lux with blinds 45°

Upto 1°F free cooling at night with blinds horizontal

SOUTH WEST

45°

Blinds 45° maintain 0.5° - 1°F lower ambient temperature with no peak in afternoon

Daylight levels sustained at 400 – 600 lux with blinds closed

Upto 1°F free cooling at night with blinds open 19


BLINDS CLOSED VS BLINDS HORIZONTAL (0°) SOUTH EAST •

Daylight levels sustained at 200 lux with blinds closed

Upto 2° F free cooling at night with blinds horizontal

CLOSED

SOUTH WEST

Since the day with blinds horizontal began at much warmer temperature than the day with blinds closed, early morning indoor temperature comparison is not done

Daylight levels sustained at 300 lux with blinds closed except for slight peak in the afternoon

Upto 1° F free cooling at night with blinds open

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KEY FINDINGS SUMMARY SOUTH EAST OPERATIVE TEMP RADIANT PEAK SHAVING NIGHT TIME FREE COOLING BLINDS OPEN VS CLOSED

2° F

8° F

3° F

BLINDS HORIZONTAL VS 45°

1 - 2° F

6° F

1° F

BLINDS CLOSED VS HORIZONTAL

NA

NA

2° F

SOUTH WEST OPERATIVE TEMP RADIANT PEAK SHAVING NIGHT TIME FREE COOLING BLINDS OPEN VS CLOSED

NA

8° F

3° F

BLINDS HORIZONTAL VS 45°

0.5 - 1° F

NA

1° F

BLINDS CLOSED VS HORIZONTAL

NA

NA

1° F

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SURFACE RADIANT TEMPERATURES ANALYSIS 1 : 79.7 °F

1

2 : 80.5 °F External louvers keep lower temperature on upper field of glass

2

1 : 81.1 °F 2 : 85.4 °F 2

1

External blinds keep lower temperature than interior blinds

1 : 83 °F 2 : 84.1 °F 2

1

Sophisticated light redirection blinds keep lower temperature than upward concave blinds 22


West Test Bays

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BLINDS CLOSED (CONTROL) – AMBIENT TEMPS

Blinds Open show maximum heat gain

Blinds 45 ° show some heat gain as compared to blinds closed

Base Case

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BLINDS CLOSED (CONTROL) – RADIANT TEMPS

Blinds Open show maximum heat gain

Blinds 45° shows slight peak in radiant temperature unlike blinds closed

Trade-off between energy savings and outdoor view

Blinds 45° can be proposed instead of blinds closed to provide access to view

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SURFACE RADIANT TEMPERATURES ANALYSIS MORNING

BLINDS CLOSED

1

BLINDS OPEN

2

78.4 °F

1 : 75.6 °F 2 : 77.4 °F AFTERNOON

BLINDS CLOSED

1

BLINDS OPEN

2

1 : 82.3 °F 2 : 87.4 °F External louvers [1] maintains lower temperature than internal blinds

88.6 °F Blinds Open increase the surface radiant temperature by 1° F as compared to Blinds Closed 26


CONTROLS DECISION FLOW CHART

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ENERGY PLUS SIMULATION

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SIMULATIONS & ENERGY SAVINGS

BASE MODEL

SOUTH BAYS April 10th To 13th : Blinds Open vs Closed

12.46% May 1st To 31st

: Blinds Horizontal vs 45°

3.94% WEST BAYS May To August : Blinds Open vs Closed

2.24%

MODIFICATIONS • • •

• • •

PNNL prototype model for small office building in Climate Zone 5A Based on DOE reference model, updated with ASHRAE 90.1.2010 standards Four perimeter zones (16.4 ft deep) and core Window to Wall Ratio: South – 24.4% Other orientations – 19.8% Unitary HVAC system Daylighting controls as per ASHRAE 90.1 standards

Matched building orientation to the existing

Used Pittsburgh weather file

Changed the set point schedules zone wise according to the results from the field tests

Results reflect only cooling energy savings and does not include lighting loads 29


TRIPLE BOTTOMLINE CALCULATIONS WEST Total Building investment costs Initial investment costs

$ 261 Per sq ft $ 0.36

Per employee $ 261

$ 0.01

$ 3.16

First year savings:

First Tier Considerations

ECONOMIC Second Tier Considerations

ECONOMICS + ENVIRONMENT Third Tier Considerations

ECONOMICS + ENVIRONMENT + EQUITY

Energy savings

4.85 %

ROI (Economic) 15 year Net Present Value (Economic only) Energy savings

$ 96 0.12 kWh

25 kWh

$ 0.01

$ 1.22

First year Savings : Air pollution emissions Cumulative ROI (Economic + Environment)

7%

Cumulative 15 year Net Present Value (Economic + Environment)

$ 133

First year savings: Health benefits Productivity increase (3% x 35% x 45,000) Absenteeism Annual Baseline Savings Cumulative ROI (Economic + Environment + Equity) Cumulative 15 year Net Present Value (Economic + Environment + Equity)

-

-

$ 2.36

$ 473

-

-

$ 2.38

$ 477

732 % $ 14,509 30


LEED 2009 NEW CONSTRUCTION CREDITS

Energy & Atmosphere (EA) Credit 1: Optimize Energy Performance Indoor Environmental Quality (IEQ) Credit 7.1: Thermal Comfort—Design

Indoor Environmental Quality (IEQ) Credit 8.1 & 8.2: Daylight and Views Innovation in Design (ID) Credit 1 – Possibility can be explored

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USE SOLAR SHADING DEVICES WITH DYNAMIC CONTROLS TO SAVE ENERGY AND INCREASE OCCUPANT COMFORT !!

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FUTURE RESEARCH

Complete the remaining set of experiments

Perform controlled field experiments

Test single type of blinds at a time on different locations (internal & external)

Develop model of existing structure and simulate using real time weather data

Triple Bottom Line Calculation for the entire project

Studies relating health & productivity benefits with blinds intervention

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Special Thanks to ‌‌

Synthesis Advisors : - Vivian Loftness - Azizan Aziz - Erica Cochran EEB HUB Team Members: - Bertrand Lasternas - Flore Marion Energy Modeling expert : - Omer Karaguzel

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MSSD Thesis Presentation