Paul Walitsky CHMM President
The Industrial Ecology Co LLC
Walitsky@industrialecologyllc.com
LEED puts a significant effort into energy efficiency. Its point total will often be the deciding factor in the level of achievement. With a possible ten points at stake, it is one of the most lucrative areas for harvesting points. Lighting efficiency plays a major role in this quest. The statistics are well known. Across the country lighting consumes somewhere near 25% of the energy use in the country. Depending on your building type it can be between 40 and 50% of the energy usage. (higher in office buildings, lower in factories, higher in hospitality industry, lower in medical facilities).
Improving your lighting energy efficiency is one of the easiest ways to reduce energy usage. While Energy Star and before that the Green Lights Program emphasized energy reductions through lighting, much remains to be done. This short guide, by no means complete will attempt to point you in the right direction and help locate areas which can save you energy and save you money. As 2006 has been the warmest year on record, the concerns about Global Warming have taken on a more immediate concern. This is one of the ways you can contribute to the reduction in atmospheric reduction without an increase in cost. It hit the upper 60s in January in New York City.
A few basics; The major families of lighting available are Incandescent( Invented in 1871, Fluorescent lighting developed in the 1930s and Compact Fluorescent (late 1970s), High Intensity Discharge lamps (Mercury vapor 1930s-1940s, High Pressure Sodium early 1960s, Metal Halide 1970s) and now beginning to move from indication to illumination Light Emitting Diodes (late 1960s). You will note that none of this is brand new. The lighting industry changes slowly.
What has changed over the years is the increase in efficiency, improvement in color and it the ability to render colors closer to nature and a major improvement in the life of the lamps.
Incandescent and Halogen Lamps
Efficiency of incandescent lamps ranges from less than 10 lumens per watt to perhaps 15 lumens per watt. Halogen lamps can improve this by perhaps 30% by getting up to 25 lumens per watt. If you have incandescent lamps and need to preserve ambiance or are faced with fixture considerations by all means move to a halogen lamp. If you need to turn the lamp on and off quickly and need instant-on capabilities, halogen should be your choice.
Compact Fluorescent Lamps
The bigger gain in efficiency, when eliminating incandescent lamps, is to replace the lamps with compact fluorescent lamps. The CFL has come a along way since the late 1970s. It is lighter, more efficient and has much more versatility. There are R-40s, R30s and R-20s, PAR lamps, “A” shapes, spiral shapes, dimming lamps and three way lamps. For commercial applications, pin based lamps in various wattages and colors are available. The energy savings are approximately a factor of four. (i.e. a 15 watt lamp replaces a 60 watt lamp, a 25 watt replaces a 75 watt). Two caveats, many of these cannot be used in enclosed fixtures, but there are some that can. And secondly many of them are not instant starting but take a few seconds to come up to full brightness. Best of all prices have come down.
Linear Fluorescent Lamps
The older fluorescent technology involves a lamp is 1.5 inches in diameter (known as a T-12 , the number is the diameter in eights of an inch), the more efficient fluorescent use lamps which are 1.0 inches (T-8) diameter or more recently lamps which are .625 (T-5) inches in diameter. The T-12 lamps run on electro-mechanical ballasts which generate a fair amount of heat. The T-8 lamps and T-5 lamps run on electronic ballasts which generate less heat are smaller and maintain their lumen output for a longer period with less drop-off.
If you have T-12 lamps anywhere in your building they should be changed to T-8 or T-5 lamps. You must also change the ballast. (T-8 lamps cannot run on the electromechanical ballast). Check with your local utility and with your State Public Utility Commission. There may well be an incentive or rebate available to help offset the cost. In New Jersey the utilities, offer, depending on the circumstances up $35 per fixture, in New Hampshire depending on your size you might get half of the cost as an incentive. (The Utilities know it is cheaper to encourage energy efficiency then it is to build a new power plant). If you get below certain watts per square foot levels for your building type there may also be a Federal Tax Deduction available. Check with your accountant and utility.
The T-8 lamps come in several color variations and wattages. The standard four foot lamp is available as a 32 watt, 30 watt, 28 watt and 25 watt. (The 25 watt lamp output is about equal to an older 34 wattage T-12). Because there is a reduction in the amount of heat generated by the ballast, there is a saving in HVAC costs. (In some areas of the country the rule of thumb is ¼ to 1/3 of a watt saved in HVAC for every watt saved in the ceiling).
Remember, you cannot run a T-8 on a mechanical ballast. With T-5 lamps you do need a new fixture (and a program start ballast) The pins will not fit in a T-8 fixture and the lamp is not quite 4 feet long.
High Intensity Discharge Lamps
This family consists of three lamps types: mercury vapor, High Pressure Sodium and Metal Halide. Mercury Vapor lamps are the “SUVs” of the lamp industry. They use too much energy and lose too much light too quickly. Change them to Metal Halide. (You can get a High Pressure Sodium lamp with will run on the mercury vapor ballast. But if you want white light then change both and go to Metal halide. There is a big movement away from High Pressure Sodium to metal Halide. Based on the specifications it would appear that you would not be saving energy however, perception is in the eye of the beholder. Because the Color rendering of HPS is 22 and the Metal Halide color rendering index can be in the 90s, A lower wattage metal halide appears brighter then the HPS lamp. A parking lot installation in California successfully changed 250 watt HPS to 175 Metal halide. When specifying Metal halide you should seriously consider Ceramic Metal halide. Efficiency is improved as is color constancy. With a quartz arc tube standard metal halide may shift color over time as the rare earth salts migrate through the quartz arc tube. With Ceramic that degradation is eliminated and the color remains true.
Paul Walitsky CHMM
President
The Industrial Ecology Co LLC
Walitsky@industrialecologyllc.com
