Increased Task, Reduced Ambient Lighting

Summary

Increased Task, Reduced Ambient Lighting

Office Lighting: Low Level Ambient Lighting w/Task Lighting vs. High Level Ambient Lighting

A flexible lighting system delivers light appropriate for each task and each occupant, along with a low level of ambient lighting. This practice usually saves electricity when compared with the conventional practice of lighting the entire space sufficiently for most (but not all) occupants and tasks.

Energy Savings: 20%

Energy Savings Rating: Limited Assessment What's this?

Level	Status	Description
1	Concept not validated	Claims of energy savings may not be credible due to lack of documentation or validation by unbiased experts.
2	Concept validated:	An unbiased expert has validated efficiency concepts through technical review and calculations based on engineering principles.
3	Limited assessment	An unbiased expert has measured technology characteristics and factors of energy use through one or more tests in typical applications with a clear baseline.
4	Extensive assessment	Additional testing in relevant applications and environments has increased knowledge of performance across a broad range of products, applications, and system conditions.
5	Comprehensive analysis	Results of lab and field tests have been used to develop methods for reliable prediction of performance across the range of intended applications.
6	Approved measure	Protocols for technology application are established and approved.

Details

Increased Task, Reduced Ambient Lighting

Office Lighting: Low Level Ambient Lighting w/Task Lighting vs. High Level Ambient Lighting

Item ID: 219

Sector: Commercial

Energy System: Lighting--Design

Technical Advisory Group: 2009 Lighting TAG (#1)

Baseline Example:

Baseline Description: Standard office lighting
Baseline Energy Use: 3.7 kWh per year per square foot

Comments:

The 2009 Northwest Commercial Building Stock Assessment indicates an average lighting power density of 1.2 W/sf for office space, with about 58.6 weekly hours of operation--(from Tables C-IL-1 and C-SC-2, respectively). This is equivalent to about 3,047 hours per year. In contrast, for new construction or major retrofits, the allowable lighting power allowance for office space under the 2009 Edition of the WA energy code standard is 0.91 W/sf. For our baseline, use 1.2 W/sf x 3,047 hours/year x kWh/1000 W-hrs = 3.65 kWh/sf.

Manufacturer's Energy Savings Claims: Currently no data available.

Best Estimate of Energy Savings:

"Typical" Savings: 20%
Energy Savings Reliability: 3 - Limited Assessment

Comments:

Wide range of possible savings, depending on how well this is done. 20% is conservative. Can be 60-70%. The change in LPD over code, the depth of the control strategy, the fraction of floor area that adopts the strategy.

Energy Use of Emerging Technology:

3 kWh per square foot per year What's this?

Energy Use of an Emerging Technology is based upon the following algorithm.

Baseline Energy Use - (Baseline Energy Use * Best Estimate of Energy Savings (either Typical savings OR the high range of savings.))

Technical Potential:
Units: square foot
Potential number of units replaced by this technology: 456,600,000
Comments:

Assume applicability in offices: 456.6 million sqft of heated office space (from Table C-GB-1 of the Commercial Building Stock Assessment, NEEA, 2009 http://neea.org/resource-center/regional-data-resources/commercial-building-stock-assessment Note that savings will be reduced in the 15.1% of office space equipped with occupancy sensors and the 5.7% of office space with daylight dimming systems.

Regional Technical Potential:
0.34 TWh per year
39 aMW
What's this?

Regional Technical Potential of an Emerging Technology is calculated as follows:

Baseline Energy Use * Estimate of Energy Savings (either Typical savings OR the high range of savings) * Technical Potential (potential number of units replaced by the Emerging Technology)

First Cost:

Installed first cost per: square foot

Comments:

Low. TRC net levelized cost mostly well below $40 per MWh. First cost 15 to 25 cents per square foot. Sometimes negative first cost where the number of luminaires can be reduced.

Cost Effectiveness:

Simple payback, new construction (years): N/A

Simple payback, retrofit (years): N/A

What's this?

Cost Effectiveness is calculated using baseline energy use, best estimate of typical energy savings, and first cost. It does not account for factors such as impacts on O&M costs (which could be significant if product life is greatly extended) or savings of non-electric fuels such as natural gas. Actual overall cost effectiveness could be significantly different based on these other factors.

Reference and Citations:

Terry Clark, 10/07/2009. Breakthrough in Office Lighting For Today’s Changing Offices
Finelite, Inc.

Gruzen Samton LLP, 03/05/2007. Manual for Quality, Energy Efficient Lighting
Gruzen Samton LLP

David Nelson, 07/23/2010. Energy Efficient Lighting
David Nelson & Associates

ALG, 01/01/2014. Lighting Design Considerations
Advanced Lighting Guidelines

ALA, 01/01/2013. Lighting Fundamentals
American Lighting Association

IALD, 01/01/2014. Why Use A Lighting Designer?
International Association of Lighting Designers

Kevin Gauna, 09/08/2008. Developing Lighting Technologies Integrated Office Lighting
California Lighting Technology Center

Jonathan Puleio, 05/01/2012. Bright Ideas: Ergonomic considerations for lighting the modern office
General Services Administration

Alan Hedge, 01/01/1991. Cornell University: Lighting the Computerized Office
Cornell University

Ira Krepchin, 03/01/2000. New Dimming Controls: Taking It Personally
E Source

Rank & Scores

Increased Task, Reduced Ambient Lighting

2009 Lighting TAG (#1)

Technical Advisory Group: 2009 Lighting TAG (#1)
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