Overview

This playbook offers guidance on commercial lighting system upgrades that can reduce energy use by as much as 75%, pay back in less than three years, and improve occupant satisfaction and well-being.

Playbook topics include: advanced lighting system fundamentals; tips for selecting lighting fixtures and control systems; strategies to maximize the use of daylight;  and best-practices for navigating the retrofit process.

Context

Lighting accounts for one-third of electricity use in New York City commercial buildings. By upgrading to higher efficiency fixtures and installing advanced lighting controls, commercial building owners can reduce their lighting energy use by as much as 75%.

Due to significant strides in lighting technology, advanced lighting system upgrades are among the most cost-effective means for commercial building owners to lower their energy use, cut operating costs, and reduce their carbon footprints. Lighting upgrades also improve lighting quality and aesthetics, which can improve occupant well-being and increase property values and rents.

Lighting system upgrades can be completed at varying levels of complexity and cost, from replacing individual components (such as lamps, ballasts, or sensors), to relighting or redesigning entire spaces. Projects that successfully improve the office environment and save energy will select upgrade measures to meet the specific needs of the space and organization. Typically, the more comprehensive the retrofit, the greater the improvement to lighting functionality, comfort, aesthetics, and project payback.

Anatomy of an Advanced Lighting Retrofit

Careful retrofits can improve the function of lighting systems and enhance occupant comfort while saving energy and money.  Understanding the process, players, and goals at the beginning of a retrofit can make the project easier and more successful.

The following steps can help guide successful lighting retrofit project:

1. Identify Goals and Requirements – These can include energy saving goals, budget, current and anticipated use of the space, and occupant concerns.
2. Select Technology –  Technology selection may include lamps and fixtures, advanced control systems, and/or daylighting systems.
3. Invest & Finance – Lighting retrofit costs and payback vary depending on project scope, degree of disruption, and market forces.  Payback can be improved by accessing incentives and financing.
4. Install & Commission – It is crucial to have a project manager oversee installation and ensure that systems are properly commissioned prior to full operation.
5. Educate Stakeholders – Engaging maintenance personnel, facility managers, and office occupants throughout the retrofit process can help ensure project success.

Fixture Selection

Selecting the right fixture for each job maximizes lighting quality, flexibility, visual interest, and energy savings.  In addition to cost, be sure to consider a fixture’s output, efficacy, and lifespan when making your selection.

• Output – The amount of light emitted by a source, measured in lumens.  The more lumens, the brighter the light
• Efficacy – The efficiency with which a light source converts power into light, measured in lumens per watt (LPW)
• Lifespan – Fluorescent lights essentially fail at their end of life, while LEDs slowly dim as they age.  Use the L70 rating to compare anticipated LED lifespans

Fixtures also have different lighting distributions tailored for different purposes, such as providing light to walls or ceilings, adding sparkle or ambient glow, or providing focused task lighting. Some fixtures integrate multiple distribution types to serve multiple purposes.

Controls Selection

Network Options include:

• Wired
• Wireless
• Autonomous Systems
• Power over Ethernet (PoE)

Controls Options include:

• Stand-Alone Controls & Sensors (e.g. wall switch, vacancy sensor, and ballast)
• Centralized Control Systems (e.g. integrated, autonomous lighting system)
• Connected Networks (e.g. multi-space networked control system driven by a BMS)

Control Strategies include:

• Zoning
• Smart Time Scheduling
• Vacancy & Occupancy Sensors
• Daylight Harvesting
• Personal Dimming & Tuning
• High-End Trim
• Circadian Programming
• Peak Demand Response

Daylighting

Daylight harvesting, or “daylighting,” systems save energy by reducing the level of electric lighting in response to available daylight.  The Building Energy Exchange’s 2012 study, Let There Be Daylight, found that New York City building owners could collectively save $70 million each year by introducing daylight responsive lighting systems.

Successful daylighting depends on:

• Availability of sufficient daylight
• Physical conditions that promote daylight distribution (i.e. high window headers and light-colored interior finishes)
• Effective control mechanisms to avoid unwanted glare and solar heat gain (i.e. automated shades)
• Lighting control performance that is not distracting or disruptive to occupants (i.e. avoids sudden changes in illuminance levels)

Design for Lighting

Interior design decisions have tremendous influence on lighting efficiency.  Planning smart layouts with low-cost, passive design solutions can improve energy savings while enhancing occupant comfort.

For example, open-plan offices with work stations located near windows are typically more energy efficient than closed-plan offices, as a higher number of occupants can benefit from access to daylight and views.  The placement of interior walls, clerestories, and fixed furniture determines the extent to which daylight can penetrate deeper into a space.