Q 1 - What's the easiest way for my company to cut our energy demand during Stage 2 and Stage 3 power emergencies?
A - Turn off unneeded lights. Most new buildings have "bi-level" switching, which means that all but the corridors and small spaces have two switches to control the lighting in a room. In most cases, you can turn off one of the switches and still have relatively uniform lighting. Use task lighting if additional light is needed at the tasks. Flipping that switch cuts your lighting energy in half. If you do it throughout the building, you can cut your demand by 15 or 20%. It's a no-cost way to save, and often it has no adverse effects on the occupants. Give it a try before the next power crisis hits. If your company is really organized, put stickers on the switches that should be turned off when you need to save power.
Also consider turning off or enabling power saving features of computers, monitors, printers, fax machines, copiers, and other office equipment.
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Q 2 - Is there an inexpensive way that I can save a lot of lighting energy right away?
A - Of course, that depends on the type of building and hours of use. Here are a few of the easiest and least expensive ways to reduce energy consumption immediately:
a. In office buildings and other places where people work at desks, buy table lamps and equip them with compact fluorescent lamps. A 30 to 40 watt compact fluorescent produces about the same amount of light as a 150-watt incandescent lamp, and will produce over 50 footcandles in an area near the lamp. Use light colored shades to produce ambient light. Then, use bi-level switching to reduce the overhead lighting system in the space. If you buy smart, the cost per employee will be less than $100, and there is virtually no cost for electrical labor. Look for Energy Star Label for all CFLs to ensure maximum savings and performance.
b. Also consider buying motion sensor plug strips. These are plug strips with built in surge protection that have a small motion sensor that is attached to an individual's desk or monitor. The motion sensor turns off task lights, the monitor, and other non-essential office equipment if the worker is away from their desk. Again, this can be installed easily at any time.
c. In hotels, homes and many other building types, screw in compact fluorescent lamps in place of as many incandescent lamps as possible. This may take some research and professional assistance to find the proper lamp, but it is now possible to screw in a dimmable lamp as well as many different types of non-dimmable lamps. Remember, the proper ratio of incandescent to compact fluorescent is between 3:1 and 4:1. In other words, each watt of compact fluorescent replaces between 3 and 4 watts of incandescent. Also, consider buying compact fluorescent adapters that permit you to replace the lamp without replacing the entire assembly in the future. Look for Energy Star Label for all CFLs to ensure maximum savings and performance.
d. Look for lights that can be turned off permanently or groups of lights that can be controlled by a time clock or photoelectric switch. For instance, in a space with a skylight, turn lights off by day. Have the control device installed by a qualified electrician.
e. Review maintenance and operating procedures of every property. Identify how lighting or energy use can be reduced through smart procedures.
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Q 3 - Should I replace my incandescent lamps at home with compact fluorescent lamps (CFL)?
A - Yes. With the cost of electricity going up dramatically, all incandescent lamps that operate for more than three hours a day should be replaced with CFLs. Fortunately, the prices of CFLs have been coming down dramatically. CFLs equipped with electronic ballasts can now be purchased for less than $10.00 in many locations. CFLs are three to four times more efficient than incandescent sources and last many times longer. CFLs equipped with electronic ballasts offer better efficiency, instant start, less flicker, and longer life. The color rendering of the many newer CFLs are now much improved and are virtually indistinguishable from the incandescent sources. You can even obtain CFLs designed for dimming using your existing incandescent dimmers.
You should look for lamps that carry the EPA Energy Star label to ensure maximum energy efficiency and performance.
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Q 4 - We were told that it doesn't save energy to turn the lights off when we leave a room because it takes more energy to start up a fluorescent light than to just leave it on. What is the correct answer?
A - As a simple rule of thumb, you should always turn off lights if they will not be used for more than five minutes. While most lighting systems have a brief power surge when starting, the amount of energy consumed is very small. Frequent switching of lights, especially fluorescent lamps, will shorten lamp operating hours, but the lamp will probably last as long in years, and the energy savings will be important.
As an alternative to manual switching of your fluorescent lamps, you may want to consider installing occupancy sensors to automatically turn the lights on and off. These devices will turn the lights off if occupancy is not detected for a preset period of time. Greater energy savings can be achieved by using a shorter preset period, which in most installations, is recommended to be between five to ten minutes.
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Q 5 - Is a halogen lamp an energy efficient source?
A - Halogen lamps are a type of incandescent lamp. In general, halogen lighting systems are not as energy efficient as fluorescent or HID lighting systems. For instance, the 300-watt halogen lamp used in a typical torchier (floor lamp with uplight) produces about the same amount of light as two 32-watt fluorescent lamps. For this reason, halogen and other forms of incandescent lamps should be avoided for general lighting, especially in commercial and industrial buildings.
However, halogen lamps are more energy efficient than incandescent lamps and are energy effective choices in many specific applications. For instance, in retail track lighting, replace conventional 120 watt R-40 and ER-40 reflector bulbs with 60-watt PAR-38 halogen infrared reflecting (IR) lamps, saving 60 watts in every socket and getting more light on the product. Also, use 60-watt halogen general lighting bulbs in chandeliers and sconces instead of 75 watt "A" lamps and save 15 watts for each lamp. Because there are many lighting applications where compact fluorescent lamps are not appropriate, halogen and halogen IR lamps are important energy saving lighting products in some applications.
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Q 6 - Will dimming an incandescent or halogen lamp save energy?
A - It saves some energy, but the light output drops much faster than the energy saved. This is because as an incandescent lamp is dimmed, it still consumes a lot of energy generating infrared heat, so the energy savings are not as great as the reduction in light. If you need less light, a better solution is to use a lower wattage lamp, or use a more efficient source like a CFL. For instance, dimming a 75-watt incandescent lamp by 25% will still use 66 watts. Use a 50-watt lamp at full brightness instead, or install an 18-watt CFL. You might also consider a 23 watt DIMMABLE CFL available now in many home improvement stores, which will only use about 18 watts when dimmed, giving you the ability to "turn up" the light.
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Q 7 - Is it true that the State of California is going to ban the inefficient, high power consuming halogen torchieres?
A - All torchieres manufactured on or after March 1, 2003, must be designed so that they cannot accommodate lamps that consume more than 190 watts. A torchiere is a tall floor lamp that shines light upward toward the ceiling. Inefficient, high power consuming halogen torchieres use a quartz (tungsten halogen) tube lamp of 300 watts or more.
California Appliance Efficiency Regulations ban all torchieres that consume more than 190 watts. The reasons for this new rule are twofold. First, these halogen fixtures are very energy inefficient as a source of light (they produce more heat than light) and a significant contributor to summer space cooling loads. Second, numerous fires have been attributed to these fixtures in California and other states. The temperatures produced by the 300 and 500-watt halogen lamps are high enough to ignite drapery and other materials that come in close contact with these lamps. Severe burns can also occur by touching the halogen lamp.
As an alternative to high wattage halogen torchieres, you may want to consider torchieres equipped with energy efficient compact fluorescent lamps (CFL) and high frequency electronic ballasts. These efficient fixtures use up to 75% less electricity than the halogen fixtures, while producing the same amount of light. These low powered CFLs also eliminate the fire and burn-touching hazard.
Fortunately, there are several energy efficient models available in home improvement stores. Most are equipped with three-way switches, or have fully dimmable lamps and ballasts. Color rendering is excellent and virtually indistinguishable from incandescent sources.
Although the high efficiency torchieres cost more to purchase than halogen torchieres, with the energy costs rising dramatically on the West Coast, you can expect a quick recovery of your investment through energy savings. Assuming you use your torchiere for only three hours a day, if you purchase a fully dimmable 55-watt CFL torchiere (which retails for about $50) instead of a 300-watt halogen, you can expect a payback period of less than ten months. Torchieres equipped with three-way switches are generally less expensive and therefore have even shorter payback periods. Additional savings will be realized due to reduced summer cooling loads, which will further reduce your payback period.
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Q 8 - During the last series of stage 2 and 3 power alerts we turned off the overhead fluorescent fixtures in many of our offices. We are working in the dark. Is there a way to save and see?
A - A new advanced table lamp lighting system called the "Berkeley Lamp" is hitting the market the summer of 2001 to help address this very question. Developed by scientists at LBNL (supported by both CEC and DOE) in cooperation with the SMUD, SCE and PG&E this lamp is ideally suited to reducing lighting energy use and to increase lighting quality in office work stations, home offices, and hotels. Designed to look like a typical table lamp, this system uses two independently dimmable CFLs in an up/down configuration. So, users have a highly efficient, bright optical system they can precisely control. The user can operate the lamp in an uplight (indirect) mode to create indirect lighting ideal for computer intensive tasks, or in a downlight (direct) mode, which is more efficient, for reading and writing tasks. In a typical workstation, small office, or hotel guest room environment the occupant can turn off or reduce the overhead lighting and use the table lamp as the primary lighting system. Initial field studies have indicated 40-70% reduction in lighting energy use with a strong user preference for the table lamp. The lamp will be further field tested by the utilities. First production of the lamps is also planned for the summer of 2001.
The lamp is being first introduced to the California market via a utility cooperative including SMUD, SCE and PG&E. This introduction will include a series of high visibility demonstrations around the state, which will also include measurements, and verification of energy savings and user acceptance. Other large institutions are also buying some of the first production for field studies. The "Berkeley lamp" is commercializing this summer and will be available to facility managers and the public for purchase (estimated cost will be in the 130-140$ region). Distribution strategies are currently being identified in order to get fast market introduction given the current energy situation in California. For more information about the Berkeley Lamp, Please email Dr. Michael Siminovitch MJSiminovitch@lbl.gov at Lawrence Berkeley National Labs.
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Q 9 - Do fluorescent lamps flicker?
A - Yes, fluorescent lamps do flicker, but the newer technologies that utilize electronic ballasts operate at levels where the flicker is beyond human perception. The older magnetic ballasts operate on 60 cycles per second (60 Hz), and the lamps actually flicker on and off 120 times per second. Many people feel they can see them flicker, especially in presence of computer or TV displays. However, the new electronic ballasts/T-8/T-5 lamp systems operate at frequencies about 20,000 to 40,000 Hz, which is far beyond human perception. So, for all practical purposes, the new electronic ballast and T-8/T-5 lamp combinations do not flicker.
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Q 10 - We have older T-12 lamp and magnetic ballasts in our office. How much energy can we expect to save by switching to T-8 lamps?
A - Often a lot. If you replace your existing T-12 lighting system with T-8 lamps on a 1:1 basis, which includes replacing magnetic ballasts with electronic ballasts, you will reduce the amount of lighting energy by 17-48% depending on the specific lamps and ballasts. In some cases, you can also remove some of the existing T-12 lamps and not replace them. The resulting energy savings in a 2:1 replacement can be as high as 75%, but the resulting light levels will only be about 40-50% of existing conditions.
Retrofitting lighting systems in this way is a common way to reduce lighting energy cost. Many energy service companies, lighting contractors and lighting service companies can provide you with an energy audit that will show you the options and make recommendations whether a 50% light level reduction is acceptable. Some utility companies may also offer a rebate or other incentive if you switch.
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Q 11 - I am thinking about replacing my T-12 lamps. Should I replace them with T-8 or T-5 lamps?
A - T-8 lamps are an excellent choice for retrofitting into a lighting fixture that has T-12 lamps. It will be necessary to change the old magnetic ballast(s) to efficient electronic ballast(s). At the same time the fixture, lens and/or louver should be thoroughly cleaned. It may also be possible to reduce the number of lamps if the task being performed has changed since the lighting was installed - for example the use of computers that has replace paper-based tasks. Also, it is quite possible to specification-tune T-8/ electronic ballast system design by utilizing the many different ballast factors available among the ballast manufacturers. Light level and power are virtually linear with ballast factor so savings can be realized in demand, energy, and materials.
T-5 lamps are 5/8" diameter, and operate only with electronic ballasts. They are very bright, are about 2 inches shorter than T-8 or T-12 lamps, and are intended for use in new fixture designs and are NOT suitable for retrofit. The new high output T-5 HO lamp with over 5,000 lumens output can replace two regular lamps, resulting in fewer lamps and ballasts installed. The T-5 HO lamps work best in indirect lighting systems and in high ceilings where they do not contribute to glare. In addition, the smaller diameter of the T-5 lamps offers better optical control resulting in higher luminaire efficiencies.
If you want to retrofit existing fixtures, use T-8 lamps. If you have the opportunity to redesign your lighting system, consider using either T-5 or T-8 lamps. In some high performance lighting systems, T-5 or T-5 HO lamps may be the more energy efficient choice for new fixtures. However, T-8 lamps provide the best combination of efficiency and low cost and should be used in most retrofit applications.
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Q 12 - We have an overhead fluorescent lighting system in our office building. Can we remove some of the fluorescent lamps and save energy?
A - The answer is complicated because there are different types of ballasts. A fluorescent lamp requires a ballast, which is a type of electrical device, to operate. For standard 4-foot lamps, you are most likely to have one of the following:
* The most common ballast is a two-lamp magnetic ballast. You probably have this type of ballast if you are using F40T12 lamps. It is a series ballast, which means that if you remove one lamp, the remaining lamp will glow dimly and sputter. You should not remove a lamp from this type of ballast to save energy. (There are also three-lamp magnetic ballasts and four-lamp magnetic ballasts, and they are parallel-series types that will behave much like a two-lamp ballast, above. These are very rare, however.)
* There are single lamp magnetic ballasts. Removing a lamp won't have any effect on any other lamps, but the ballast will continue to draw some energy. Removing a lamp does save energy, but not nearly as much as when you also disconnect the ballast.
* Many buildings use the modern F32T8 lamps and parallel circuit electronic ballasts. The most common electronic ballasts are three-lamp and four-lamp. In general, removing one or more lamps is fine and power is reduced. The remaining lamps will usually put out a little more light, but the reduction in power and light is almost linear.
* There are also series and series-parallel electronic ballasts. A series electronic ballast has the same limitations as a series magnetic ballast.
Remember, a lot of three-lamp lighting fixtures in California are wired so that there is one two-lamp ballast in one lighting fixture and two two-lamp ballasts in another, with the third lamp in each fixture sharing the second ballast. But these lighting systems are usually wired to two switches, and you can reduce the light level easily by switching.
The first test is to remove one lamp and see what happens. If you have series ballasts, removing one lamp will cause one or more other lamps to turn dim and sputter. In this case you should abandon the idea of removing lamps.
However, if the remaining lamp or lamps continue to operate, you either have parallel circuit ballasts or single lamp ballasts. Removing lamps is generally OK, and with each lamp removed you reduce power. With electronic ballasts, the power will go down proportionately with the number of removed lamps. With magnetic ballasts, the power will go down, but not as much. It is better to disconnect magnetic ballasts than to simply remove lamps.
As with any type of electrical work, qualified electricians should be employed to disconnect ballasts and make other wiring changes. If you arenÍt sure what to do, contact a lighting maintenance or energy services company. Often in a few minutes they can correctly identify your lamp and ballast types and explain your options.
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Q 13 - When I am renovating a commercial building, should I upgrade to more efficient lamps and ballasts or replace the existing lighting fixtures?
A - The decision depends on your particular situation, which is discussed below. Renovations of buildings often involve numerous code issues, including Title 24, which will affect this decision. Your architect, engineer or contractor should be able to advise whether new lighting fixtures will be less expensive than retrofitting your existing lighting system.
Generally, if your renovations are modest and you are not changing your lighting system in any major way, most older lighting systems can be retrofitted to use less energy. You should probably RETROFIT your lighting system if:
- The fixtures are not being moved and your architect or contractor recommends retrofitting the fixtures in place. This may be due to cost savings or for seismic or asbestos management reasons.
- You have a relatively modern lighting system, such as parabolic troffers, that require simple cleaning and retrofitting of T-8 lamps and ballasts. Retrofit reflectors may permit delamping, which is often suitable and saves additional energy.
- You have an open commercial or industrial lighting system that can be easily retrofitted in place. Because of seismic hangers and other issues, removing and replacing a fluorescent fixture is not quite as easy as it appears.
You should probably REPLACE your lighting system if:
* It is an old style lighting system, such as one with plastic lenses, that is no longer suitable for the use of the space. Modern office space with computers generally should be updated to either parabolic troffers or suspended indirect lighting systems, and the energy savings will often pay for the cost of the new lighting system.
* The existing lighting system is sufficiently old, worn, broken or damaged to warrant a new system. For example, in a 20-year-old troffer a retrofit should include a complete disassembly, replacement of lens, complete washing, new reflector and sockets, new wiring, new ballast, and new lamps. Often the cost of removing the fixture, proper disposal and a new fixture installed is less.
This is a common decision facing almost all building owners and managers. You should be able to obtain competent and effective advice from your architect, engineer, lighting consultant, contractor, lighting management company, or energy services company. Regardless of which you do, some utility companies may also offer a rebate if you reduce your lighting energy use.
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Q 14 - We are using incandescent reflector lamps to light our store displays. Is there anything else we could use to save energy?
A - If you are using the traditional glass reflector lamp, with rounded edges, (known as an 'R' lamp or a 'BR' lamp), there are two options, and with the bonus of longer life.
- Use PAR lamps. These are available in PAR20, PAR30 or PAR38 sizes (approx. 2 1Ú2", 3 3Ú4" or 4 3Ú4" dia), and are a heavier glass. PAR lamps tend to concentrate the light more, so it is important to choose the beam spread of the new lamp carefully. Use "flood" or "wide flood" PAR lamps unless you are familiar with beamspreads and aiming lights. In most cases, a 120-watt R-40 or BR-40 lamp can be replaced with a 90 watt halogen wide flood lamp with excellent results.
- PAR Infrared reflecting (IR) lamps are an even more efficient version of lamps. IR lamps may be harder to find, and are more expensive than regular PAR lamps. Currently, IR lamps are available in 50 watt PAR 30 (replacing 75 watt PAR30 and R30 lamps) and 60, 80, and 100 watt PAR38 (replacing 90, 120 and 150-watt halogen lamps and all wattages of R-40, ER-40 and BR-40 lamps).
If you are using low voltage MR16 lamps, there are now IR versions of these lamps too. The 37-watt MR16IR lamp replaces the 50-watt MR16, and the 50-watt MR16IR replaces the 75-watt MR16.
If you have an existing track display lighting system, you might consider changing from 120-volt fixtures to low voltage. Low-cost replacement track lighting "heads" using 37 watt MR16IR lamps can often replace 75-100 watt R-30 heads, especially for lighting detailed objects like window displays, artwork, jewelry, and some key displays like mannequins.
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Q 15 - Can HID sources be dimmed?
A - Yes, HID sources can be safely dimmed down to approximately 50% power and 30% of full light output using special ballasts and control devices. But it should be noted that as HIDs are dimmed the color shifts, so in general, HID dimming is only suitable in areas where color rendering is less important. Also keep in mind that existing HID luminaires must have new ballasts installed to permit dimming, and doing this is often more expensive than the complete HID lighting system.
However, before installing dimming in HID systems, consider fluorescent replacements. New fluorescent fixtures using 4 to 6 T5-HO lamps have been designed for "high bay" applications up to mounting heights of 30 to 40 feet. These fluorescent systems are much more efficient than ordinary HID lighting, allowing maximum power to be reduced by 20-25%. But the big advantage of fluorescent technology is the ability to switch lamps instantly and in pairs. This permits more effective on/off and dimming control.
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Q 16 - Can I use motion sensors with high-pressure sodium and metal halide lamps (HID) to reduce outdoor lighting energy usage?
A - HID sources can work well in conjunction with motion sensors that offer two levels of lighting (also called stepped ballasts or hi-lo). In these applications, the low level light is provided (50% power and 30% full light output) when no motion is detected. When the motion sensor detects motion, it triggers the lighting to go to the high light level. The hi-lo lighting may be appropriate in parking lots, parking structures, and in areas where safety and security are important. Do not use motion sensors with HID lamps in an on/off mode, since the long warm-up time precludes a practical application.
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Q 17 - Can we use reduced wattage bulbs in a HID installation?
A - In some cases, yes. There are a few screw-in metal halide lamp products that save energy when operated on existing ballasts. These include a 360-watt lamp designed for 400-watt standard ballasts, a 225-watt lamp designed for 250-watt ballasts, and a 150-watt lamp designed for 175-watt ballasts. Note that these are specific retrofit lamps, and not just any lamp can be used.
You should NOT try to install, say, a 250-watt lamp in a fixture with a 400-watt ballast without changing the ballast. The ballast determines the wattage, and will overdrive the lower wattage lamp beyond its rating, which could be dangerous and will certainly shorten lamp life.
If you are willing to replace the ballast, consider using a pulse-start metal halide lamp and ballast system. Pulse start lamps are different than ordinary metal halide lamps. They generally use 20-30% less electricity at the same illumination level, and therefore are more energy efficient than traditional metal halide lamps. Pulse start lamps require new sockets and socket wiring as well as a new ballast, however, so before undertaking this step, be certain to address all of the related technical issues.
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Q 18 - Do outdoor lighting ordinances result in dark and unsafe streets and parking lots?
A - The answer is no, if the ordinance is written properly and the lighting is designed for the proper security requirements. In fact, a properly written ordinance can greatly improve the public's health and safety while eliminating glare, light trespass, light pollution, and save energy. A well designed ordinance will improve night time driving conditions by eliminating disabling glare sources in the driver's field of vision. A good ordinance will result in better lit streets by eliminating light pollution and light trespass and putting all the light on the tasks where it is needed. It will account for the effective use of light by allowing the lighting designer to select products with sharp cutoff when it is required to reduce overall brightness and glare. It will result in energy savings by allowing lighting designers to select proper lighting control devices to turn off lighting that is not needed. It will also allow a lighting designer to select products with an appropriate level of vertical brightness for areas where safety and security are a concern or where the identification of pedestrians, obstacles or other hazardous situations is required. A well-designed ordinance will emphasize the importance of maintaining the uniformity of lighting levels and brightness ratios to reduce the impact of disabling glare.
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Acknowledgments
The California Energy Commission would like to thank the members of the Advance Lighting Advisory Committee (ALAC) and other individuals who assisted with the development of this document. Special thanks go to Jim Benya (Benya Lighting Design), Cheryl English (Lithonia Lighting), Bill Daiber (San Diego Gas and Electric Company), David Crowford (International Dark Sky Association), Peter Bleasby (Osram Sylvania), Larry Ayers (BKI/EPRI), Jack Melnyk (Southern California Edison Company), Doug Mahone and Nehemiah Stone (Heschong Mahone Group), Michael Siminovitch of Lawerence Berkeley National Labs, and Thomas Tolen (TMT Associate) who provided timely and substantive comments on this document.
The Commission's project manager for this document is Maziar Shirakh, P.E., Senior Mechanical Engineer. Other Commission staff who assisted with the development of this list were Gary Flamm, Lighting Specialist, and Bob Aldrich the Commission's Webmaster.
For more information on these and other lighting related issues, please refer to the newly updated Advanced Lighting Guidelines (ALG), which is scheduled for public release on May 30, 2001. The ALG is jointly sponsored by the California Energy Commission, Pacific Gas and Electric Company, Southern California Edison, Electric Power Research Institute, San Diego Gas and Electric, Iowa Energy Center, and New York State Energy Research Development Authority (NYSERDA). The sponsors hired the New Buildings Institute (NBI) to manage the project. The ALG will be available on the Webpages of the sponsors and the NBI after May 30, 2001.
More tips on how to save energy on all building systems, including HVAC, building envelope, and lighting systems, may be found on this Web site on the home page.
