Lutron Electronics Co., Inc. is a Registered Provider with The American Institute of Architects Continuing Education Systems. Credit earned on completion of this program will be reported to CES Records for AIA members. Certificates of Completion for non-AIA members are available on request. This program is registered with the AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.
Daylight Autonomy through Automation AIA/CES/HSW/SD Course Number DAA13 (1.0 Learning Units)
Lutron Electronics Co., Inc. is a registered Provider of GBCI Approved Courses for Continuing Education. This program is registered with GBCI for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement of GBCI of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.
Daylight Autonomy GBCI Approved Course Course Approval Number 0090010301 (1.0 Continuing Education Hours)
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© Lutron Electronics Co., Inc. 2013
Learning Objectives• Identify current building design trends and the reality of
what happens when the intended design is not maintained and daylight is not properly managed
• Understand the concept and benefits of daylight autonomy and its energy savings metrics
• Recognize the difference in useful daylight zone and performance between a wired lighting control system with manual shades and one with wireless technology and automated shades through daylight analysis and energy simulation
• Understand the differences in the installed cost and return on investment between the two systems
Unmanaged Daylight = Glare, Heat, & Waste
Placeholder: Show diagram comparison • 8000 fc of daylight outside a 5x10 window = # of linear fluorescent light
fixtures (54 watt T5HO) it would take to emit the same amount of light onto a worksurface inside the window
Daylight – Manual Shades
Inkarojrit, Vorapat. Balancing Comfort: Occupants’ Control of Window Blinds in Private Offices. Diss. University of California, Berkeley, 2005
46%
75.2%
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Less than once per day
Perc
ent R
espo
nses
Frequency of Adjustment
Manual Shade Adjustment
Sunny Day
Cloudy day
• For any given day 45-75% of shades will not move at all.
– They will only move 54% of the time on a sunny day.
– They will move less than 25% of the time on a cloudy day.
• Only 10-20% of all manual shades are actively controlled.
Automated systems can balance daylight autonomy more than 75% of the time.
Market Drivers
ASHRAE 90.1-2010 – Mandatory requirements for:
• Area controls • Automatic lighting
shutoff • Bi-level lighting • Daylight harvesting • Exterior lighting control • Parking garage lighting
control • Stairwell lighting control • Designer to ensure that
light controls are functionally tested
Stairwell lighting control
DOE Ruling October 19, 2011: ALL states commercial building codes
must meet or exceed ASHRAE 90.1-2010 by Oct. 18, 2013
Market Drivers
LEED NC Credits 8.1 and 8.2: Daylight and Views (IEQ) • Intent: To provide building occupants with a
connection between indoor spaces and the outdoors through the introduction of daylight and views into the regularly occupied areas of the building.
Credit 8.1: Daylight • Prove a minimum daylight illumination level
of 25 footcandles in at least 75% of regularly occupied areas
Credit 8.2: Views • Achieve a direct line of sight to the outdoor
environment between 30 inches and 90 inches above the finish floor for building occupants in 90% of all regularly occupied areas
Daylight AutonomyWhat is “daylight autonomy”?
• Describes the percentage of work hours where useful daylight is available and there isn’t a need for electric light
– “Useful daylight”: glare-free; enough for daylight harvesting benefits
• Metrics are based on measures of time
• Controlled admission and management of daylight
• Benefits: Increased revenue through higher
productivity Lower operating expenses through energy
savings
Energy Savings Metrics• Daylight Autonomy (DA) –
percentage of work hours where the design illuminance is completely achieved through daylight
• Continuous Daylight Autonomy (cDA) – similar to DA but gives partial credit to the hours where the daylight cannot complete achieve the design illuminance
• Spatial Daylight Autonomy (sDA) – percentage of area where 30FC is achieved for at least 50% of work hours through daylight
Metrics continued…Glare Metrics: • Max Daylight Autonomy (maxDA)
– percentage of work hours where 10x the design illuminance is exceeded
• Annual Sunlight Exposure (aSE) – number of hours per year with direct sun
Combined Metrics: • Useful Daylight Illuminance (UDI)
– percentage of work hours where the illuminance from daylight is between 20FC and 200FC
Building Example – Daylight Analysis
Vista Center – COSCIA MOOS Architecture
Daylight Analysis Wire Frame Model – 14th Floor
Building Example – Typical Office Plan Vista Center – COSCIA MOOS Architecture
30,000 square feet
14th – 24th Floors
30,000 square feet
Building Example – Daylight Analysis
Vista Center – COSCIA MOOS Architecture
December 21st, Noon
December 21st, 4 pm
Building Example – Daylight Analysis
Vista Center – COSCIA MOOS Architecture
June 21st, Noon
June 21st, 4 pm
We Have a Choice…
Meet codes with manual shades and standard technology
• ASHRAE 90.1 – 2010 –“Daylight Zone Requirement” mandates:
Daylight sensor Occupancy sensor Switch
Manual shades (6) Switching Ballast
“Daylight Zone Requirement” mandates:
Occupancy
We Have a Choice…
EXCEED codes and realize FULL potential of savings with automated shades and wireless technology
Dimming Ballast
Wireless Daylight sensor Wireless Occupancy sensor Wireless Keypad
Automated shades
Choice 1: Manual Shading (closed)
Vista Center – COSCIA MOOS Architecture Useful daylight zone (manual shades) = 12ft
44 Switches 73 Occupancy Sensors 15 Daylight Sensors 440 terminations 185 feet of conduit
Wired Lighting Control System with Manual Shades
Choice 1: Manual Shading (closed)
Vista Center – COSCIA MOOS Architecture
14th – 24th Floors
90%
20%
UDI Results
Choice 2: Automated Shading
Vista Center – COSCIA MOOS Architecture
14th – 24th Floors
90%
20%
UDI Results
Choice 2: Automated Shading
Vista Center – COSCIA MOOS Architecture
Expanded useful daylight zone (automated shading) = additional 12ft
Useful daylight zone (manual shades) = 12ft
Wireless Lighting Control System with Automated Shades
Installed cost = ∆ 3.44%
44 Switches 73 Occupancy Sensors 15 Daylight Sensors 0 feet of conduit
Daylight – Shading Pros and Cons
Cost
Energy Savings Productivity
Comfort
Uniformity
Elegance
Flexibility
Code Compliance
Integration Perceived
Maintenance
Simple Return on Investment
$0.00
$0.10
$0.20
$0.30
$0.40
$0.50
$0.60
South North West
Ligh
ting
Ene
rgy
Cost
($/f
t²/yr
)
Lighting Annual Energy Usage
Closed
Automated
AVG Savings = $0.34/ft²/yr [83%]
**Lutron Electronics, Inc. worked with Purdue University to analyze the benefits and savings potential of automated shading systems. The results showed the impact of how automated shades significantly reduce annual lighting energy usage.
(Manual)
Simple Return on Investment
0
1
2
3
South North West
Ligh
ting
Ener
gy U
se (k
Wh/
ft²/y
r)
Lighting Annual Energy Usage
Closed
Automated
AVG Savings = 1.6 kWh/ft²/yr [83%]
**Lutron Electronics, Inc. worked with Purdue University to analyze the benefits and savings potential of automated shading systems. The results showed the impact of how automated shades significantly reduce annual lighting energy usage.
(Manual)
Importance of Glare Control
• Daylight glare can result in 25% lower productivity1
• Assuming $40 per hour salary plus benefits & overhead costs
• $10 reduction in productivity per employee per hour
• $30 per window bay per hour
• For only 100 hours of glare potential
• ~ $3000 in lost productivity per window bay
1Heschong Mahone Group, Inc., 2003. Windows and Offices: A study of office worker performance and the indoor environment. Prepared for California Energy Commission.
Internal Rate of Return
Lighting Cost Savings Motorized Shade Adder
Incremental Cost
Annual Energy Savings
10 Year IRR
20,000 + 6.25%
(10,000)
$ 5,125**
20.5%
(3.44%)
Standard Lighting Controls and Manual Shades
Wireless Lighting Controls and Automated Shades
- 2.81%
**Energy savings based on average cost of electricity in New York, NY.
Expected Return Based on Cost of Electricity
Cost of Electricity
$ 0.18 - $ 0.21 per kWh $ 0.14 - $ 0.17 per kWh $ 0.10 - $ 0.13 per kWh
Payback
4-5 years 6-7 years 7-10 years
0
1
2
3
4
5
6
7
8
9
10
11
$0.10 $0.12 $0.14 $0.16 $0.18 $0.20
Pay
bac
k (Y
ears
)
Cost of Electricity (per kWh)
Expected Return Based on Cost of Electricity