Editor’s note: This article first appeared in the September/October 2015 edition of Business Energy.
There are several simple conditions under which a facility operator should consider doing a lighting retrofit, notes Bob Smith, P.E., Director, Energy Marketing Solutions, Eaton’s Cooper Lighting business. Simple ones to consider include high energy rates for which a lighting retrofit can help reach a faster payback with incentives offered by the utility to “buy-down” the cost of the installation, which helps reduce the initial investment, he adds.
“Timing of group re-lamping helps justify the rebate,” says Smith. “When a facility or a space is up for a group re-lamping, the funds planned for the re-lamping can be used to help justify the retrofit. As the time of use increases, the kilowatt-hour savings expand. For example, a system that operates at 24/7 has a faster payback than one that only operates three hours per day.”
Additionally, there are more complex elements to consider, he adds. The scope of the technologies that can be replaced with LED luminaires affordably covers not only incandescent/halogen systems but also HID, compact fluorescent, linear fluorescent, and induction.
“Spaces that have lighting operating for long periods to allow for safe conditions when occupied can achieve higher savings with controlled LED luminaires,” notes Smith. “The required time of use can be dramatically reduced resulting in higher kilowatt-hour savings. There are various means of controlling the LEDs.”
One is occupancy control for vacancy and motion sensing. “This reduces kilowatt-hours based upon the activity in the space. The system can be commissioned to turn off or reduce light levels,” he says.
Another means: daylighting control to sense for reduction in power where sunlight is present. This reduces kilowatt-hours based upon the amount of sunlight in a space, he says. Additionally, controls integrated within the overall building energy management system can be implemented in retrofits.
“It is most cost effective when the system is already in place such as zero to ten Vdc low-voltage control,” says Smith. “LEDs commonly offer continuous dimming with deeper energy savings than traditional sources like linear fluorescents that include ballasts with the same zero to ten Vdc control. As network security of wireless controls within a building are addressed, these will eventually facilitate simpler commissioning with the opportunity for deeper energy savings.”
To reduce commissioning expenses, integrated sensors within luminaires are effective in many applications such as small spaces and where granular control is desired without additional wiring, he notes.
“Areas that are very difficult to reach can be replaced with properly-designed luminaires that last, not only reducing energy costs, but [also] maintenance savings with higher reliability.”
When undertaking a lighting retrofit, safety is the paramount factor to consider. “Equipment available on the market may save energy and the initial cost may be low, but the safety of the installation is critical,” says Smith. “Be sure to know the ‘real cost’ of the lighting equipment proposed and the amount of time it really takes to install in accordance with the safety requirements.”
Smith advises facility owners and operators to avoid technologies that require luminaire rewiring, and to be careful of not fully understanding what ballast each luminaire has installed. “This is a signal of retrofits that can result in alterations that render the luminaire unsafe and remove the original equipment manufacturer from their responsibilities,” he says. “Be aware that UL-recognized [Underwriters Laboratories, which refers to product safety testing] components do not mean the retrofit will be installed safety.”
Smith also advises facility operators to have an audit conducted by someone who understands luminaire construction.
The occupancy of the space is another factor to consider when doing a lighting retrofitting. “If the space stays occupied 24/7, scheduling the retrofit can be difficult and can also be costly,” says Smith.
Consider tall mounting heights with many obstructions. “If luminaires are installed at tall heights that require equipment to perform the retrofit, survey the space for obstructions that will make it difficult for the equipment to maneuver around to allow the contractor to perform the retrofit,” he points out.
Another factor is that mounting and wire connections vary by luminaire type. “Be sure to understand how a luminaire is mounted and supply wiring is connected,” says Smith. “The luminaire may require special hangers and special plugs to be an easy retrofit.”
Smith says building owners and operators can start with DesignLights Consortium-qualified and Energy Star-certified luminaires. “This makes sure that one is comparing manufacturers by having a third-party validate the basic performance levels,” he says. “Once that is done, be sure to have a lighting design done because not all luminaries perform the same way in every space. This will assure the light levels are adequate and the energy minimized optimized.”
Eaton offers a broad range of controllable energy-efficient luminaires “that are designed to last,” audit support, lighting layouts support, financing support when funds are not available and the energy savings can fund the monthly expense, and DesignLights Consortium-qualified and Energy Star-certified recessed luminaires.