Which Lighting System is Right for You?
LED lighting systems are changing the way we light our indoor and outdoor spaces. In interior high ceiling applications and exterior areas that traditionally use HID fixtures, LEDs offer significant energy savings and dramatically reduce maintenance costs. LEDs paired with customizable controls can save you substantially more energy than LEDs without controls as the lighting output can be adjusted to meet project requirements. Use the chart below to determine which LED lighting system best fits your HID retrofit needs.
|New retrofit LED lamp without controls||
New LED fixture or retrofit kit without controls
|New LED fixture or retrofit kit with integrated controls|
Incentives and Savings
|Utility incentives (contact your utility for more information)||May be limited or lower than new fixture||Calculated or deemed||Calculated|
|Cost of ownership||Good||Better||Best|
There are a range of factors to consider when retrofitting an existing fixture. Your results will vary based on location, facility layout and electricity costs, among other things.
New LED lamp
HID-LEDs for replacing existing high intensity discharge lamps are screw-based LED lamps that use the existing lamp sockets in the existing HID fixture housing. Although LED replacement lamps typically offer better efficiency and longer life than existing HID lamps, their lighting distribution can't be optimized for all fixture optics. Retrofit kits and new fixtures are designed as engineered units and offer higher energy savings, better life and better lighting quality than HID-LED lamp replacements.
Types of HID-LEDs available to replace HID lamps:
Plug and Play (Type A): These lamps use the existing HID ballast (if compatible) and lamp socket. As such, installation does not require rewiring or an electrician. Plug and play HID-LED lamps are typically the fastest and least expensive way to upgrade to LED, but are also the least efficient retrofit option. They can be a short-lived solution due to potential ballast failure, ballast incompatibility or difficulty in finding a ballast replacement. Also, if dimming is desired, a compatible dimming ballast and dimmable LED lamp is required.
Line Voltage (Type B): Also known as ballast bypass, these replacements do not use the existing ballast, eliminating the ballast issues seen in plug and play lamps. They offer greater energy savings than plug and play as the ballast wattage draw is eliminated. Installation costs are higher than plug and play LEDs, as an electrician is required to remove the old ballasts and re-wire the fixture. To add or maintain dimming, the HID-LED must be dimmable and a new dimmer compatible with the HID-LED will need to be installed.
All HID-LED replacement lamps are less efficient than a retrofit kit or new fixture because the light distribution is not optimized for the fixture. A few manufacturers are offering networked control capabilities imbedded into the HID-LED lamps, allowing scheduling, dimming and even changing light distribution via a smart phone or tablet.
As with all lamp retrofits, testing a solution with a handful of fixtures before applying the upgrade widely is recommended.
New LED Fixture or retrofit kit
New LED fixtures and retrofit kits use LEDs as the light source instead of traditional high intensity discharge (HID) sources (high pressure sodium and metal halide). The LEDs are factory installed directly in the fixture without the use of traditional lamp sockets. Since fixtures and retrofit kits come with new drivers, they are typically compatible with dimming controls and networked control systems (commonly referred to as 'network control capable ready').
New fixtures usually offer higher energy savings, last longer, and have the lowest failure potential, compared with retrofit kits or lamp replacements. With new fixtures, the manufacturer designs the light distribution around the LED chips to meet industry standards of light distribution and glare control.
A retrofit kit is a bundled set of hardware designed to replace all electrical and lens components of an existing fixture while leaving the original fixture housing in place. A retrofit kit effectively creates a completely new luminaire, without having to replace the entire fixture, typically resulting in lower equipment and installation costs compared to a new fixture. Retrofit kits typically outperform LED replacement lamps installed in existing fixtures, offering longer life, better heat management, lower failure potential and higher efficiency.
With retrofit kits the manufacturer designs the light distribution around the LED chips but often designs the kit to fit in multiple different housings. A generically designed kit sacrifices some optical control (light distribution and glare control) since the kit will be installed in an existing fixture housing.
New LED fixtures and retrofit kits do not use socket-mounted or magnetically-attached LED tubes.
New LED fixture or retrofit kit with integrated controls
Integrated control fixtures and retrofit kits are generally referred to as Luminaire Level Lighting Control (LLLC) fixtures and kits. At minimum, LLLCs incorporate embedded occupancy sensors, daylight sensors and wireless controls into LED light fixtures or retrofit kits. Most LLLC products offer additional energy and occupant comfort features such as continuous dimming, task tuning (brightening or dimming each fixture or a group of fixtures to provide the ideal light level for occupants), programmable scheduling, and more. The fixtures wirelessly communicate with each other, so can operate in groups or independently.
Exterior fixture control capabilities may include photocell control, scheduling on/off, scheduling dimming levels, grouping, occupancy sensing, and lumen depreciation adjustment.
These systems provide maximum energy savings and fixture life, easy installation, and operational efficiencies. While simple payback may take longer, cost of ownership can be significantly lower on these installations, especially when factoring in maintenance savings and ease of reconfiguration.
Quality of light
From the color of the LED light to the lighting distribution of the fixture, retrofitting to LED can improve the quality of lighting in your space compared with traditional technologies. LED lighting tends to show colors more accurately and vibrantly than HID, improving the look of the space.
LED fixtures and retrofit kits can also light the space more effectively. The fixture manufacturer can shape the lighting distribution of the fixture (how the light comes out of the fixture) to optimize the lighting in your space. The optimization could be to distribute more light on the walls, which will brighten the look of the space, or in a higher ceiling space, to increase the lighting intensity by pushing more light to the floor.
One major advantage of new fixture installation is the ability to locate the lights for best distribution, whereas depending on the existing lighting layout may offer poor uniformity or inadequate light levels at the task. Reconfiguring the lighting layout in the space allows you to correctly address under or over-lit areas.
When paired with sensors and controls, LEDs can offer a range of additional capabilities. These features and functions can improve the lighting quality, enhance the occupant experience, decrease operation costs, help your new system meet building code, improve occupant performance and safety, and even help your business run more efficiently. A few of the more common Networked Lighting Controls capabilities include:
- Dimming: vary the light output of the fixture, enabling energy savings and greater occupant satisfaction.
- Occupancy or Vacancy control: regulate lighting based on presence or absence of people in a space, increasing energy savings and reducing maintenance costs.
- Daylight control: regulate the light level in response to changing daylight conditions in the space, increasing energy savings.
- High-End trim/Task tuning: adjust the output of individual lights or group of lights to a set lower maximum level, enabling energy savings, greater occupant satisfaction, and lower maintenance costs thanks to longer system life. Over time, as lumen depreciation naturally occurs, the light output can be adjusted to maintain consistent brightness for safety and comfort.
- Networking: connect all fixtures as a network, allowing them to exchange information with each other or even integrate with an Energy or Building Management Systems (EMS or BMS). Networked fixtures can be configured and controlled individually or as a group to optimize energy savings; some allow for remote configuration and control. Networking, especially using wireless systems such as LLLC, can provide reduced wiring, maintenance and reconfiguration costs and can promote greater energy savings.
- Zoning: ability to configure groups of fixtures to perform the same lighting strategies (same occupancy time-outs, same task tuning, etc.). Zoning often results in reduced cost of wiring, maintenance and reconfiguration and greater energy savings.
- Layering: combining controls strategies where applicable (occupancy, daylight sensing, dimming, high-end trim, scheduling) can optimize energy savings far beyond single control strategies.
- Color tuning (only available with color-tunable LEDs): ability to adjust the color temperature of the lamp, promoting higher occupant satisfaction and performance.
- Automation and tracking: sensors embedded in light fixtures can be used to perform a wide range of functions, from identifying unused meeting rooms, to automating door operation, to tracking products in a warehouse, enabling improved space utilization and business efficiency.
Utilities often offer enhanced incentives for lighting systems that include controls. Contact your local utility to learn about lighting controls incentives available in your area.
LEDs offer significantly longer life compared with incandescent HID technologies, resulting in less frequent replacement and lower maintenance costs. For Type "A" plug and play LED lamps that utilize an existing ballast, the ballast may fail before the LED lamp, which will require the ballast to be replaced. Unfortunately, there is no visible indicator that the ballast failed and the only way to test is to install the existing LED lamp in a fixture that is operating properly.
LED life ratings are based on the age at which the fixture or lamp will degrade to 70 percent of its original light output. This is shown on manufacturers' specification sheets as the "L70" designation. Some manufacturers list L90, which is the life when the fixture is still producing 90% of its initial light output. Look for an L70 of at least 70,000 hours or L90 of 50,000 hours.
We experience Discomfort and Disability glare when the variations of luminance (surface brightness) across the visual field are too great. Disability glare is defined by a measurable reduction in visibility with high luminance contrast. A fixture's casing, lens, and angles can help reduce glare potential.
Exterior fixtures are evaluated with the B.U.G. (Backlight, Uplight, Glare) rating system. The Glare component's effect is measured on a scale of 0-5 with 0 being the lowest potential and 5 being the highest (and least desirable) potential.
Factors to Consider when Embarking on a Lighting Upgrade
There are a range of factors to consider when retrofitting an existing fixtureThe following are important considerations that could influence your decision:
- Age and condition of ballast: When retrofitting an existing fixture with direct replacement LED lamps, consider the type and age of the existing ballast. Failure of older existing ballasts before HID-LED end-of-life will defeat the 'reduced maintenance' attractiveness of LED solutions. Some incentive programs restrict use of existing ballasts in lighting upgrades.
- Age and condition of sockets: As fixtures age, lamp sockets can become brittle due to the heat and UV exposure they experience over time. Older fixtures may need new sockets to offer best life expectancy.
- Net Efficacy: New highly-efficient LED products installed into existing fixtures can experience losses of up to 10 – 15 percent due to inter-reflected light loss – basically, light trapped within the fixture. Addition of a lens will reduce efficiency another 10 – 12 percent, or even more if the lens is old and yellowed. Note that these reductions were present with the existing HID lamps also.
- Light Distribution: The way a fixture distributes light is determined by its reflectors and lens, which are designed around the original lamp type. Replacing existing lamps with LEDs will change the distribution characteristics of the fixture, which may cause shadowing or sharp cutoff at walls. A test installation will help determine whether direct one-for-one lamp replacement will give suitable results. Be sure to evaluate the light levels, the lighting distribution and the visual look of the space in the test installation.
Labor costs: Labor costs will depend on the type of LED retrofit planned.
- LED lamps – HID-LED lamp replacement can be as simple as removing the existing HID lamps and plugging in the LED lamp. LED lamps may require incompatible ballasts to be replaced, may require removal of the existing ballast and rewiring of the fixture, or may require replacement of the ballast with a new LED driver. In all cases damaged sockets should be replaced.
- Retrofit kits – Retrofit kits install into the existing housing from below the ceiling and can be an effective alternative to LED lamps or new fixtures. They generally require removal of all internal components of the existing fixture and installation of new internal LED components.
- New Fixtures –With new fixtures the replacements do not need to be on a one-for-one basis or even in the same location, which allows for the lighting layout to be optimized in the space. Replacing or relocating a fixture may require seismic anchor wires (slack wires), which may or may not be present on the existing fixtures.
- Some types of replacements require an electrician. The new fixture, retrofit kit and replacement lamp descriptions in this guide provide additional details regarding which types of retrofits will require an electrician.
Links to a PDF and customizable InDesign files for the LED Replacements for High Intensity Discharge (HID) Lighting Comparison Tool are below.