LED High- and Low-Bay Retrofit Kits for Indoor Applications
High Bay and Low Bay Lighting: LED vs. HPS/MH
Kits containing LED arrays, drivers, cooling technology and sometimes reflectors to maintain or improve light quality, help achieve energy savings, reduce maintenance over traditional high-pressure sodium (HPS) and metal halide (MH) lighting systems, and allow customers to save money by not purchasing new fixtures and disposing of old ones.
Item ID: 413
Commercial, Industrial, Agricultural
Lighting--Lamps & Ballasts
Technical Advisory Group: 2012 LED Lighting TAG (#5)
Average TAG Rating: 2.2 out of 5
TAG Ranking Date: 04/05/2012
While the DesignLights™Consortium does list “High-bay and Low-bay fixtures for Commercial and Industrial Buildings” as a category and lists some replacement lamps, there were no retrofit high and low bay product applications as of February 2012. However, many manufacturers are offering these retrofit kits.
Most of the focus by the U. S. Dept. of Energy Solid State Lighting program on developing LED products has been on purpose-designed luminaires. But with many existing sockets, manufacturers are likely to seek to fill this market niche with retrofit kits. It is hard to imagine that the performance of the retrofits will be as good as the performance of a purpose-designed luminaire,but perhaps “close enough” will be good enough for many if the cost savings are significant enough. Some manufacturers are providing retrofit kits and lamps for their traditional street lighting and interior troffer fixtures, so one can expect to see more retrofit products for other applications in the future. Retrofit kits are one way to reduce the amount of solid waste when upgrading lighting systems.
The use of "self-cleaning glass or coatings" on fixtures could reduce the need for cleaning which would make the most of long-life and reduced maintenance claims. It may not be available in retrofit kits.
Baseline Description: 400W HID high-bay lamp on 12hrs/day
Baseline Energy Use: 2000 kWh per year per unit
The baseline operating scenario assumes that each unit requires 458 input watts (including standard magnetic ballast losses) operating for twelve hours per day, seven days a week, for 52 weeks per year. Note: According to Table 4.7 in the "2010 U.S. Lighting Market Characterization" report, average daily operating hours for Metal Halide lamps in the commercial sector is 11.1 while the number increases to 16.5 hours in the industrial sector. The weighted average is about 12.3 hours of daily operation for all commercial and industrial sector Metal Halide lamps (also see Table 4.1 for the numbers of lamps in the commercial and industrial sectors). Use 12 hours per day for determination of baseline lamp annual operating hours and energy use.
Manufacturer's Energy Savings Claims:
Currently no data available.
Best Estimate of Energy Savings:
"Typical" Savings: 73%
Energy Savings Reliability: 4 - Extensive Assessment
Most of the focus by the U. S. Dept. of Energy Solid State Lighting program on developing LED products has been on purpose-designed luminaires. As costs decline, the need for retrofit kits that will likely offer poorer performance will decrease. Retrofit LED kits and lamps designed for a 400W MH lamp replacement draw between 80 to 120 Watts. Assuming a 120 Watt replacement (offered by Cree), the energy savings are 73.8%. The savings is not this great in a lumen-for-lumen replacement, but with a well-designed LED luminaire, similar visual acuity can be achieved with fewer lumens and thus greater savings.
Energy Use of Emerging Technology:
540 kWh per unit per year
Energy Use of an Emerging Technology is based upon the following algorithm.
Baseline Energy Use - (Baseline Energy Use * Best Estimate of Energy Savings (either Typical savings OR the high range of savings.))
Potential number of units replaced by this technology:
Indoor HID lamps. 2010 U.S. Lighting Market Characterization, Navigant for U.S. DOE, 2012, Table 4-1: “Estimated Inventory of Lamps in the U.S. by End-Use Sector in 2010”. The number of Metal Halide lamps in the commercial and industrial sectors (nationwide) is estimated at 39,829,000 lamps. Four percent of this total (prorating by population of the Northwest) yields a total of 1,593,160 lamps. Use 1,500,000 due to uncertainty.
Regional Technical Potential:
2.19 TWh per year
Regional Technical Potential of an Emerging Technology is calculated as follows:
Baseline Energy Use * Estimate of Energy Savings (either Typical savings OR the high range of savings) * Technical Potential (potential number of units replaced by the Emerging Technology)
Currently no data available.
Simple payback, new construction (years): N/A
Simple payback, retrofit (years): N/A
Cost Effectiveness is calculated using baseline energy use, best estimate of typical energy savings, and first cost. It does not account for factors such as impacts on O&M costs (which could be significant if product life is greatly extended) or savings of non-electric fuels such as natural gas. Actual overall cost effectiveness could be significantly different based on these other factors.
Assuming 12 hours of operation six days per week and 9 cents per kWh, with a base case of pulse-start metal halide, the simple payback is about three years.It is important to remember how widely ranging and dynamic the prices are for these products.
As a means to facilitate the continued use of high intensity discharge (HID) fixtures while taking advantage of LED technology, some manufacturers are offering LED conversion kits for some HID fixtures, complete with external or internal drivers. The high number of existing sockets for HID lamps is a temptation for manufacturers to produce a lower cost product than an all new luminaire. Designing products to work with specific optical design and light distribution patterns while adding whatever heat-sink capability is necessary is not a one-size-fits-all solution. Active cooling systems involving fans are often part of the solution for fixtures not originally concerned with heat dissipation.
Control systems should also be considered and modified to take advantage of the new technologies’ capabilities, as well as any code compliance issues.
For a more comprehensive description of LED retrofits for high- and low-bay applications, see technology #402, LED Interior High-Bay and Low-Bay Lighting. This has more details in each of the information categories below. The information here focuses more specifically on the retrofit kits rather than LED lamps in high- and low-bay applications in general.
Standard practice is to replace a light fixture with conventional lighting technology products with a favorable combination of low cost and improved features.
For the client who wants to maintain the single lamp/luminaire form, there are a few options on the market for improving the color quality of existing HID luminaires. Using color-improved lamps, such as White Son for high pressure sodium (HPS), which changes the color rendering index (CRI) from 22 to 83/85 for 50 and 100W lamps, or for ceramic metal halide (CMH) for metal halide that brings the CRI from 62-65 up to 90. However, the ballast must generally be replaced as well, or in a few cases retrofitted with a ballast kit. While color may improve, efficiency and lamp life are compromised in most cases.
Pulse-start metal halide (MH) or CMH systems offer improved performance and energy savings. Electronic ballasts are now available but not commonly used for some models and may offer better performance and longer life. At least one company has a product that extends lamp life considerably by employing their soft-start technology, along with a control system, and including a retrofit kit for existing fixtures.
When converting an HID system to a more controllable, long-life, energy-efficient, whiter light source, recent practice has been to convert to a new technology and fixture-form, specifically linear fluorescent or in some cases induction lamps. If LED technology is desired, the standard practice is also to invest in new luminaires. As standard (probe start) metal halide systems reach end-of-life users will be encouraged to some kind of upgrade as the probe-start ballasts are being phased out.
Retrofit kits have just started entering the market in the last couple of years, but the market is likely to grow quickly similar to the way LED products for fluorescent fixtures and screw-in lamps have grown.
End User Drawbacks:
- High first cost is a barrier which may rival the cost of new fixtures.
- The time, cost, and disruption to install a kit should be considered in assessing whether to retrofit or buy new luminaires. Calibration of any new controls being added is also important.
- The lack of case studies of long-term, real world installations may be perceived as a high risk.
- Stranded costs of existing equipment and replacement lamps may make potential users continue with their existing technology until their supply of lamps run out.
- The high color temperature often produced may not be suitable for some applications.
- Reduced effective equipment life should also be considered. At the rate LED technology is evolving, the odds are high that a client will want a newer model before the first generation has reached end of life, shortening the effective life of the product.
- The need for assistance in selecting products for a specific application.
Operations and Maintenance Costs:
O&M costs primarily include lamp replacement and cleaning, both of which can be expensive and invasive with high- and low-bay lighting.If operating time remains largely the same, the O&M costs of retrofitted LED fixtures will be roughly the same as for most fixtures using tradition lighting technology.The exception is metal halide, which usually had less than half the life and therefore twice the replacement frequency.If the retrofit project includes the addition of controls that noticeably reduce operating hours, then lamp life will increase and the lamp replacement portion of O&M will decrease.
LEDs continue to offer lifetimes of 50,000 hours and up. High performance fluorescent systems may also be quite close to that range, especially with long burn times at 46,000 hours, while the pulse-start metal halide systems tend to be less than half as long. Even though the other technologies have proven track records, the life of LEDs at this time is still predicted by extrapolating lab test results, and driver technology tends to lag in life expectancy, and retrofit LED lamps have the least amount of well documented data.
For a simple conversion to improve light quality and, in the case of MH, save energy as well, there are a couple of screw-in lamp options. In the last year Philips introduced the AllStart line of replacement lamps for MH systems that will operate on either a probe or pulse-start existing ballast and, with one exception, in any operating position. Energy savings of about 18% and long lamp life of 20,000+ hours , along with high quality white light in the 4000K CCT make for an easy upgrade. Replacement lamps are available for up to 1000W MH systems. Costs range from $50-100. There is also a Retro-White MH product that runs on an HPS ballast, allowing better light quality (CRI 85) with no new ballast. These lamps run about $15 for 250W and 400W models.
For a system that includes a new ballast, the pulse startCMH system, perhaps with an electronic ballast, would provide a single lamp solution—while multi-lamped high performance fluorescent systems are currently the most encouraged for control options, light quality, and energy savings.