Resources Case Studies

Energy Savings

Summary

This project has cut peak lighting electric demand from 70 kilowatts to 30 kilowatts, or 0.43 watts per square foot—a lighting energy savings of 56%. These figures are particularly impressive in a building less than 10 years old where the original lighting was considered state of the art at the time of its installation. After a Con Edison rebate, the resulting financial savings is estimated to recoup the project cost in 3.6 years. Beyond reducing energy costs, the new system enables easy dimming for demand response and greatly improves space flexibility, occupant visual comfort, safety and aesthetics.

Related is very happy with the outcome, even though the firm learned during the process that, like any renovation project, lighting retrofits are never simple and require regular engagement and persistence.

Categories

Green Features

  1. Existing Fluorescent Fixtures

  2. New Dimmable Ballasts (not visible)
    Lutron Electrics
  3. Wireless Daylight Sensor
    Lutron Electrics
  4. Wireless Occupancy Sensor
    Lutron Electrics
  5. Wireless Sensor Module
    Lutron Electrics
“Wildly successful, despite the challenges we encountered.”
Charlotte Matthews, Related Companies

Building Facts

Project type: Commercial Interior
Location: Midtown Manhattan
Year of project completion: 2012
Base building completed: 2002
Project size: 
70,000 sf
Occupied during the retrofit? Yes


Existing Conditions

Although the corporate office lighting system was less than ten years old and built to very high quality standards, in Related’s opinion, it was already outdated.

All of the lighting was controlled by manual switches and a time clock. After the lights switched off at 9 PM, employees who found themselves suddenly sitting in the dark had to locate and reset override switches hidden in electrical closets. On many occasions after the time clock was overridden, the system failed to reset and the office lights remained on throughout the night or weekend.

Process

Related’s lighting retrofit aspirations were modest at the outset, seeking to correct some simple problems with occupancy sensors and lighting power. However, Lutron came up with a broader proposal offering significant energy savings as well as significant improvements in lighting control, comfort and safety. The proposal and incentives offered an estimated payback in under 5 years. Key plan features were replacement of existing fluorescent ballasts with digital dimmable ballasts, and installation of new wireless occupancy/vacancy sensors to replace the exisiting limitedly applicable time clock.

Design & Conditions

After surveying options in the lighting retrofit marketplace, Related decided to work with Lutron, one of the most prominent players in the industry.

Lutron’s fully dimmable system was cost effective, in part, due to its use of wireless sensors and controls. The wireless network made the actual placement of the sensors flexible and eliminated the need for costly installation of additional wiring. Additionally, the system offered easy reconfiguration into different zones without the need for rewiring. This eliminated Related’s existing problem of poor location interrupting occupancy sensor functioning.
The programmability of the occupancy sensor controls enabled further savings by allowing separate settings for working- and non-working hours.

Ultimately, this flexibility and low installation costs gave Related the confidence to install occupancy sensors not only in the conference rooms but also in private offices and open office areas, eliminating the need for a time clock.

Benefits

• Eliminates lighting of unoccupied spaces
• Custom tuned for specific needs
• Centralized, web-based control
• Significant peak demand reductions
• Demand response program eligible
• Reduced lighting loads
• Increased occupant comfort
• Lighting dims when daylight 
is sufficient

Lessons Learned

• After installation, the system was mistakenly activated in the executive offices before Related staff were trained to use and deactivate it. The mishap taught the Lutron and Related teams important lessons about quality control, testing, and communication that are crucial when implementing retrofit projects.
• Related found that the lighting retrofit required active management from start to finish, as not every LED lamp is compatible with every dimmer.
• There are many different “colors” of LED lamps to choose from (from “warm” amber to “cold” blue).
• Many LED lamps fall short of the lumen output they promise in their “X-watt equivalent” claims.
• It’s important to integrate the regular lamp maintenance contractor into the project to ensure a smooth transition. Related ultimately hired a new maintenance contractor after the existing contractor installed old lamps that damaged the new system during a minor renovation.

Conclusion

Related’s experience demonstrates that although lighting retrofits are often considered simple and straightforward matters, they can be complicated and require significant amounts of attention. Without the dedication of Related's Sustainability and Engineering staff and a strong relationship with Lutron, the project would not have succeeded.

18 months later, the lighting retrofit is on track for a 3.5 year payback, has reduced lighting energy use by 56%, and shaved peak demand from 70kW to 30kW. Although Related learned during the process that (like any renovation project) lighting retrofits demand regular engagement and persistence, the company is very pleased with the outcome.

Project Team

Related Companies
Project Owner

Lutron Electronics
Products & Installation
Con Edison
Incentive Provider

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