Lighting may be an energy-conscious FM’s low-hanging fruit, but picking the right fruit is another challenge altogether. That’s where a lighting audit comes in.
By strategically cataloging every lamp, fixture, sensor, and control in your facility, you can deal with the biggest energy hogs first and use the savings to finance other efficiency projects.
Ready to get started? These lighting consultants will walk you through the process.
When and Why: Lighting vs. Energy
Why focus on lighting instead of conducting an overall energy audit? For one thing, lighting projects typically have shorter payback periods, notes Brian Bridges, president of Lighting Audit Services.
“A comprehensive audit is usually best if there are other systems in the building that need an upgrade,” Bridges explains. “Sometimes it’s a budget issue – ‘We have X amount to do a capital project right now and lighting is the quickest way to do it.’ If you can roll a lighting upgrade in with mechanical, solar, and envelope, that’s fantastic, but that’s often not the case.”
Depending on your facility’s needs and your organization’s priorities, you may decide to take a second look at your lighting at regular intervals, especially if utilities offer incentives for efficiency improvements, explains Gary Markowitz, founder and president of Kilojolts Consulting Group. One of his clients, a national defense contractor, adheres to a schedule that ensures the company’s lighting stays efficient and up-to-date.
“They look at it in three- and five-year increments. Every five years, they may do a major capital improvement to the illumination system because the technology changes significantly,” Markowitz explains. “This customer does a general relamping on the same three- to five-year interval, and they’ll often take the maintenance cost of that into consideration when evaluating the ROI of any new upgrades.”
How to Get Started
First, consider your goals for the lighting audit – what do you want the end result to be? If you’re going to use the data to apply for rebates or a green building certification, you’re better off bringing in a third-party professional who can conduct an in-depth audit and make sure all necessary documentation is squared away. Some contracts may specifically call for an independent audit.
However, if you’re trying to find places to cut energy use or back up a funding request for an efficiency upgrade, your in-house facilities team may be well-suited for the job.
“Don’t go to the project stage based on your own lighting audit,” recommends Brian Bridges, president of Lighting Audit Services, noting that a CEM on staff or an advanced engineering team may have the appropriate auditing experience. “However, if you’re trying to create a strategy or a budgetary report for your in-house team, there are a number of ways to prepare for that.”
Consider enlisting your local utility’s energy specialists in your auditing efforts, Markowitz recommends. The utility may offer to pay part of the cost of a third-party energy audit or have someone on staff who can explain your options once you’ve presented an inventory of your lighting.
“Always call the utility or state energy office first,” Markowitz says. “When you have general notes – things like ‘I have these T12 fixtures, but I know T8s and T5s are more efficient’ or ‘I like the idea of LEDs but I don’t know what to do’ – they’ll usually have someone available with the expertise to explain your options and make recommendations.”PageBreak
3 Steps to Savings
Armed with a concrete goal and the right tools, you’re now ready to start the audit. A truly comprehensive walkthrough should cover these areas:
- Gather data. This step informs all others. Make a note of every lamp and fixture in every space, documenting important characteristics like:
• Type and age of lamp
• Type and age of fixture
• Ballasts used (if applicable)
• Location in building (including the name and function of the space)
• What controls are present (if any)
As you cover each room, consider taking a photo of every fixture type to aid analysis later, Bridges recommends. Also review recent electric bills to determine the cost of electricity – this will help you estimate the ROI of potential projects.
- Examine occupant needs. Determine the typical tasks of people working in the space, as well as how frequently spaces are typically used and for how long. The Illuminating Engineering Society (IES) issues recommended footcandle levels to ensure visual acuity and comfort for different tasks and age groups.
“One size doesn’t fit all for lighting design – not even close. What works for someone in a research lab probably won’t work in a space where people are designing with CAD on computers,” Markowitz says. “You’ve got to plan ahead and look at recommended practices for lighting the specific type of space in every case.”
Don’t neglect to measure the average traffic as well. Where do building occupants tend to congregate? Which spaces are empty more often than not? Existing building schedules can help shed light on additional sources of savings.
“Let’s say your people spend very little time in their offices because most of their time is spent in common areas for meetings. This would produce a high vacancy rate, which presents an opportunity for an occupancy sensor,” explains Bernie Erickson, division manager for Facility Solutions Group. “Do you leave the lights on until the cleaning crew gets there? There’s an opportunity to do some load shedding. There are loggers you can place in offices that will track vacancy and validate those savings, or you can use rule-of-thumb industry generalizations that you can plug in for the time being and get more exact data later.”
- Assess the space. Before starting the project, take stock of the tasks and activities in every space you’re evaluating. This impacts recommended lighting levels, visual comfort, and color requirements, explains Markowitz.
“Let’s say you have a machine shop with exposed egg-crate T12 fluorescent fixtures, and the fixture and lamps are covered with dirt from years of work in that space. The amount of light coming from it is compromised due to light depreciation from the dirt. In hindsight, that probably wasn’t the right fixture to put in service,” Markowitz says.
Renovation plans will affect lighting performance as well.
“If you’re going to repaint the area, consider what you’ll use, because the paint color will change the amount of light in the room,” Markowitz says. “The reflectance of the floor, walls, and ceiling all impact the light levels measured at the work surface. Lighter colors can result in a design with fewer fixtures or lower wattages.”PageBreak
Watch Out for These Challenges
These three issues can throw a wrench into your auditing plans. Take pains to avoid them for optimal results.
Complexity: Some well-meaning FMs may not remember to catalog every single space. Does the janitor’s closet have a light in it? If so, that lamp must be counted and the space must be measured. Rebates and incentives add another layer of difficulty because the sheer detail required can be overwhelming, Bridges notes.
Documentation: Mistakes in measurements can derail plans for financial rewards, Bridges says: “You can miss out on your tax deductions or rebates because something wasn’t documented correctly.”
That’s why it’s important to take exact measurements – many tax deductions are based on square footage, so some of your rooms may qualify, while others won’t.
Strategy: It’s easy to overlook certain opportunities that can yield big savings, Markowitz says. For example, lighting controls and daylight harvesting can dramatically reduce energy consumption, especially when used together. Utilities and state energy programs may even cover some of the cost.
Researching local and state incentives is essential, he adds, because in many areas, the information won’t come to you.
“Many utility and state organizations don’t do a very good job of marketing their efficiency programs,” Markowitz says. “If you’re considering an investment in an energy efficiency project, look for the incentives first. Use other people’s money whenever possible.”
Atlantic City, NJ
- Replace 6,500 150W incandescent lamps with 8W dimmable cold cathode fluorescents.
- Replace 29 obsolete dimming panels with new digital ones.
- Replace the computer controlling the dimming system with a new PC, theatrical show controller, and graphical user interface.
Contract Cost: $259,000
Savings: Approximately $135,000 per year
Other Benefits: Lamp life increased from 2,000 hours to 18,000.
Port Authority PATH Car Shop
New York, NY
Project Scope: Replace or upgrade over 1,600 light fixtures
in spaces including offices, shops, storage areas, track, pits, and building exterior
Contract Cost: $483,496
Savings: Approximately $121,000 per year
Other Benefits: Low color-rendering HPS light fixtures were
replaced with induction lighting on the building exterior and
long-life fluorescents on the interior, resulting in better color.
Janelle Penny firstname.lastname@example.org is associate editor of BUILDINGS.