a search for consistent metrics for lighting...
TRANSCRIPT
A Search for Consistent
Metrics for Lighting Controls
NBI Stakeholder Briefing
May 22, 2013
Overview of Today
1. Summary of NBI lighting control research
– Office of the Future
– Enlighted
2. Advanced lighting controls challenges – Specifically, how to
compare to code
3. Search for new metrics – Lighting energy
– ‘Off hours ratio’
NBI RESEARCH PROJECTS
Office of the Future Sponsors
Managed by: and
Landmark Square
• Irvine, CA
• 1,500 SF renovation
• Private offices – unique design for each
• Conference room
• Kitchen & lobby
• Showcase for Tenants
• August 2010 occupancy
Glumac
• Irvine, CA
• 8,762 SF tenant improvement
• Open office
• Private offices
• Conference rooms
• Kitchen & lobby
• January 2010 occupancy
SCE Executive Offices
Before After
BC Hydro Dunsmuir Office
Open Office: Before
After
NEEP Office
Open Office Private Office
NEEA – Commonwealth Building
• Portland, OR
• 19,000 SF tenant
improvement
• Open office
• Private offices
• Conference rooms
• Kitchen & lobby areas
• October 2010
occupancy
OTF Pilot Projects OTF Pilot
OTF
Sponsor Location
Renovation
or Tenant
Improvement
Size
(SF) Applicable Code
Glumac N/A Irvine, CA TI 8,328 CA Title 24 2005
Landmark SCE Long Beach,
CA Renovation 1,500 CA Title 24 2008
Executive Suite SCE Rosemead, CA Renovation 16,500 CA Title 24 2008
Federal
Building SCE
Los Angeles,
CA Renovation 8,024 CA Title 24 2008
NEEP NSTAR
National Grid Lexington, MA TI 6,762 ASHRAE 90.1-2004
Dunsmuir
Office BC Hydro Vancouver, BC Renovation 9,000 ASHRAE 90.1-2007
Cadillac
Fairview BC Hydro Vancouver, BC Renovation 4,200 ASHRAE 90.1-2007
Prism
Engineering BC Hydro Vancouver, BC Renovation 6,000 ASHRAE 90.1-2010
Commonwealth
Building NEEA Portland, OR TI 18,962 OR Energy Code
Veterans Admin San Diego
Gas & Electric San Diego, CA Renovation 3,040 CA Title 24
Enlighted Control System Elements
Control Unit /Power Pack
Sensor
Gateway
Ethernet
Green Energy Manager (GEM)
Dimming Ballast
Three Enlighted Installations
Enlighted Pilot Site Location Size of Installation
Fred Hutchinson
Yale Building Seattle, WA 20,000 SF
REI Headquarters Kent, WA 15,000 SF
Kivel & Howard Office Portland, OR 5,418 SF
CHALLENGES
Challenges with Lighting Control
• Lighting Power Density (LPD) is the most common metric in lighting codes – Calculates total connected load of lighting
– LPD expressed in Watts / Square Foot (W/SF)
• Inconsistent approach to ‘valuing’ controls in various codes
• When advanced lighting controls are involved, demand (LPD) needs to be converted to energy – Energy expressed in kWh/SF
Challenges of Comparing Code
LPD to Measured Performance
Connected Load 0.83 W/SF
Controls Credit 0.66 W/SF
Actual Performance Max 0.25 W/SF
Title 24 2005 Baseline1.18 W/SF Lighting power allowance
1.18 w/sf (Title 24-2005)
Installed LPD 0.83 w/sf
Adjusted project LPD 0.66 w/sf
Operational LPD is ~0.25 w/sf
Glumac Average Daily Profile
Demand (LPD) vs. Energy
• Since LPD (W/SF) is not a good proxy to compare to measured energy performance (kWh), NBI averaged measured power demand over various time frames.
– Average weekday daytime lighting power density (Mon-Fri, excluding holidays, 6:00 a.m. – 6:00 p.m.) is considered most appropriate comparison, but other averages are provided for reference.
Code Calculated Approach Compared to
Measured Average Daytime LPD
Pilot Site
Applicable Code
Code LPD
Calculated
Connected LPD
% Difference
from Code
Measured Ave
Weekday LPD
% Difference
from Code
Glumac CA Title 24 2005 1.18 -29.7% -83.1%
Landmark CA Title 24 2008 1.37 -3.6% -71.5%
Executive Suite Ca Title 24 2008 0.96 -9.4% -47.9%
Federal Building CA Title 24 2008 0.87 -9.2% -62.1%
Dunsmuir Office ASHRAE 90.1-
2007 0.81 -38.3% -37.0%
Cadillac
Fairview
ASHRAE 90.1-
2007 1.10 -45.0% -65.0%
Prism
Engineering
ASHRAE 90.1-
2010 0.93 +8.0% -73.0%
Prism Average Daily Profile
DEER Code Prediction
Post Retrofit
Pre Retrofit
Comparing Code Predictions to
Measured Energy Performance
0
0.25
0.5
0.75
1
1.25
1.5
0 3 6 9 12 15 18 21
Po
we
r D
em
and
(W
/sf)
Hour of Day
Dunsmuir - Average Weekday Hourly Power Density Compared to DEER Based Projection
DEER Code Projection Baseline Period Performance PeriodBefore controls After controls
Annualized Energy Savings Predictions
Pilot Site
Pre retrofit
Annualized
Energy
(kWh/SF-year)
Code Baseline
Annualized
Energy
Prediction(kWh
/SF-year)
Post Retrofit
Annualized
Energy
(kWh/SF-year)
Energy Savings
Percent
Difference
from Code
Energy Savings
Percent
Difference from
Existing
Condition
Glumac N/A 3.47 0.99 - 72% N/A
Landmark N/A 3.65 1.75 - 52% N/A
Executive
Suite 4.24 2.14 1.87 - 12% - 43%
Federal
Building 4.03 2.28 1.70 - 25% - 58%
Dunsmuir
Office 4.41 4.49 2.43 - 46% - 45%
Cadillac
Fairview 3.84 3.43 1.45 - 57% - 62%
Prism
Engineering 1.67 2.42 0.85 - 65% - 49%
Pilot Site
Applicable Code
Code LPD
Calculated
Connected LPD
% Difference
from Code
Measured Ave
Weekday LPD
% Difference
from Code
Glumac CA Title 24 2005 1.18 -29.7% -83.1%
Landmark CA Title 24 2008 1.37 -3.6% -71.5%
Executive Suite Ca Title 24 2008 0.96 -9.4% -47.9%
Federal Building CA Title 24 2008 0.87 -9.2% -62.1%
Dunsmuir Office ASHRAE 90.1-
2007 0.81 -38.3% -37.0%
Cadillac
Fairview
ASHRAE 90.1-
2007 1.10 -45.0% -65.0%
Prism
Engineering
ASHRAE 90.1-
2010 0.93 +8.0% -73.0%
Lesson Learned in OTF
• Code metric (in power demand) does not
easily compare to measured results (in
energy)
• While these metrics are of interest to
utilities, the market is not necessarily
concerned about savings over code.
Enlighted Testing Protocol
System Retrofit
‘As-Is’ Baseline
Adjusted Baseline
‘Out of Box’
Designer Preference User Preference
Enlighted System Defaults Turned On
New Lamps & Dimming Ballasts
Occupant Survey
Contractor Survey
Ener
gy S
avin
gs O
pp
ort
un
ity
Enlighted Yale Building
Average Weekday Profile
Enlighted REI
Average Weekday Profile
Enlighted Kivel & Howard *
Average Weekday Profile
* Savings are
attributable to both
delamping and addition
of lighting controls
Estimated Energy Savings
Compared to Existing Baseline
Fred Hutch
Yale
Building
REI
Headquarters
Kivel &
Howard*
Out of Box 41% 35% 32%
User
Preference 59% 39% 36%
Designer
Preference N/A 35% 37%
Off Hour & Weekend Ratios *
Off Hour Ratio:
• Comparison of average LPD during the unoccupied hours to the occupied hours during weekdays
• Calculates the percentage of lights left on when the space is unoccupied at night
Weekend Ratio:
• Comparison of average LPD during weekend hours to occupied hours during the weekday.
• Calculates the percent of lights left on when the space is unoccupied on weekends
* Lower is better!
Off Hours and Weekend Ratios Yale Building REI Kivel & Howard
Off Hours Ratio
Weekend Ratio
Off Hours Ratio
Weekend Ratio
Off Hours Ratio
Weekend Ratio
Existing Baseline
30% 14% 44% 26% 31% 18%
Adjusted Baseline
23% 10% 48% 35% 38% 15%
Out-of-Box Mode
8% 2% 17% 12% 19% 12%
User Preference
13% 6% 17% 17% 18% 13%
Designer Preference
N/A N/A 20% 16% 18% 13%
Enlighted Energy Performance
• 35 – 59% measured savings over existing
• Excellent retrofit savings potential for sites with little or no lighting control
• Actual savings depends on the baseline condition and how the space is used
• More robust savings opportunity with: • High baseline condition
• Variable occupancy patterns
• Longer operating hours
Lighting Controls: Key Takeaways
• Code metric (in power demand) does not easily compare to measured results (in energy)
• Measured results indicate savings may be far greater than code calculations currently estimate.
– Utilities and customers alike may not be getting ‘credit’ for controls systems that are designed, installed, commissioned and operating properly
• While these metrics are of interest to utilities, the market is not necessarily concerned about savings over code.
