Lighting is one of the easiest places to cut energy use in many facilities, but finding the right place to start a retrofit or relamping project can be a real hurdle.
That’s where a lighting audit comes in. It may be time-consuming, but identifying the biggest energy hogs and dealing with them first will pay dividends in the form of cost savings that you can use to finance future efficiency projects. Ensure your audit’s success by starting off on the right foot.
Why Not Conduct An Energy Audit?
Lighting may have a shorter payback period than a comprehensive energy audit, which is best deployed if there are other systems in the building that already need an upgrade, explains Brian Bridges, Founder and President of Lighting Audit Services.
“Sometimes building owners target lighting if there is a budget issue – in other words, ‘We have X amount of money to do a capital project right now and lighting is the quickest way to do it,’” Bridges says. “If you can roll a lighting upgrade in with mechanical, solar, and envelope, that’s fantastic, but that’s often not the case.”
Having the in-house facilities team conduct the audit is a great way to find places to cut energy use or back up a funding request for an efficiency upgrade, Bridges adds. A third-party professional may be necessary if you plan to use the audit data to apply for rebates or a green building certification.
Also consider enlisting your local utility in your auditing efforts, recommends Gary Markowitz, Founder and President of Kilojolts Consulting Group – the utility may offer to pay part of the cost of a third-party audit or have someone on staff who can examine your options once you’ve inventoried your lighting.
“When you have general notes – things like ‘I have this many T12 fixtures, but I know T8s and T5s are more efficient’ – they’ll usually have someone available with the expertise to make recommendations,” notes Markowitz.
3 Steps to Slash Energy
When you’re ready to start the audit, make sure that your walkthrough accounts for these three areas.
1) Gather data. Note every lamp and fixture in every space, including characteristics like the manufacturer, the type and age of both the lamp and the fixture, whether ballasts are used, wattage, their location in the building (including the name and function of the space), and what controls are present, if any. Bridges recommends taking a photo of every fixture type to help you with analysis afterward. Review recent electric bills to determine what you’re paying for electricity, a step that will help you estimate the ROI of potential improvements.
2) Determine occupant needs. Record what tasks workers perform in each space, as well as how often they use the lighting and for how long. Consult the Illuminating Engineering Society’s footcandle recommendations for different tasks and age groups to see if you’re overlighting any areas.
Also examine traffic through your facility, determining where occupants tend to congregate vs. areas that are frequently empty. Existing building schedules can help with this.
3) Assess the space. The tasks and activities you looked at to determine occupants’ required light levels will also help you determine whether the fixtures in each space are suitable for the environment around them.
“Let’s say you have a machine shop with exposed egg-crate T12 fluorescent fixtures, and the fixture and lamps are covered with years of dirt,” says Markowitz. “Now the amount of illumination is compromised due to light depreciation from the dirt. In hindsight, that probably wasn’t the right fixture to put into service.”
These issues can sidetrack your auditing success, so make sure to avoid them.
Volume: Every space means every space, even the smallest ones. A janitor’s closet with one hanging light in it still counts, so don’t forget to account for its lamp and measure the space on your audit.
Documentation: Rebates and incentives can add another layer of difficulty to accounting for everything due to the sheer amount of detail required. It’s vital that you take exact measurements, Bridges explains – many tax deductions are based on square footage, for example, so some of the spaces in your facility may qualify while others don’t.
Strategy: Don’t overlook retrofit opportunities that could yield savings, Markowitz says. Lighting controls and daylight harvesting can both dramatically reduce energy usage, especially when used together. Utilities and state programs may cover some of the cost, but it’s vital that you research them because in many areas, local organizations don’t market their efficiency programs widely.
Janelle Penny firstname.lastname@example.org is Senior Editor of BUILDINGS.