Lighting
To get the most benefit from your windows and light fixtures, brighten interior surfaces by repainting them with white or light-colored paint. Dark surfaces absorb light. More light from light fixtures or windows is needed to provide the same amount of illumination to working surfaces in rooms with dark walls, ceilings, floors, and furnishings than in rooms with white or light pastel surfaces. The difference is dramatic. One office needed just half as many light bulbs after changing from dark to off-white paint and from darkbrown to light-tan carpet. In areas where light-colored walls don't provide the desired ambiance, consider using darker accent colors on just a few walls or parts of walls.
In areas with strong sunlight most of the year and significant cooling loads, the benefits of light interiors are sometimes offset by the need to provide more cooling because the light, bright spaces "feel" hotter. In such cases, darker colors may be a better choice inside the building.
Older light fixtures and light bulbs, especially incandescent and metal halide light bulbs, are energy wasters. So are older fluorescent starters, ballasts, and tubes. Not only are they electricity hogs, but up to half of the energy that they use produces heat instead of light. This heat increases the energy needed for air conditioning. Older fluorescent fixtures that have reached the end of their useful life should be replaced by more energy-efficient fixtures that use T–8 or T–5 fluorescent tubes (figure 6).
Figure 6—This light fixture has three T-5 fluorescent tubes.
Controls allow
turning one, two, or all three tubes on, so that
light levels can be adjusted
for individual preference and the
amount of daylight in the room. Most of
the light from the
fixture is directed down, but some light shines on the
ceiling,
which helps reduce the contrast between the ceiling and fixture.
Incandescent light bulbs that burn out should be replaced by compact fluorescent bulbs in most cases. Compact fluorescent bulbs are more expensive to purchase, but their longer lamp life and lower energy use make them several times less expensive to purchase and operate than incandescent bulbs. In a year or so, the cost of new fluorescent fixtures can be recovered through energy savings when you're replacing metal halide and older fluorescent light fixtures. The same is true when you replace incandescent bulbs with compact fluorescent bulbs.
Be careful when purchasing compact fluorescent bulbs. Bulb life and the color of the light produced vary greatly by model and manufacturer—be sure to check the label for the rated life of the bulb and for a color rending index (CRI) of 82 or higher. Also, be cautious about replacing incandescent bulbs with compact fluorescent bulbs in exterior fixtures in cold climates, because some fluorescent ballasts don't work in cold temperatures. Most compact fluorescent bulbs will not work with dimmer switches.
- More information about replacing lamps and fixtures will be in a forthcoming tech tip.
Two of the biggest energy wasters in office, shop, and warehouse buildings are lights left on when nobody's using the space and lights that stay on even when the daylight streaming through windows or skylights is much brighter than the lights themselves.
Occupancy sensor switches (figure 7) use motion or heat to detect the presence of people. They turn lights off after a certain amount of time when no one is in the room, and turn the lights back on again as soon as someone enters. Occupancy sensor switches that simply replace regular light switches are available for about $30 from home supply and hardware stores or for $50 from the GSA.
Figure 7—In 2006, occupancy sensor switches replaced standard switches
in all the offices, restrooms, machine rooms, and service rooms at MTDC.
Each office had two switches to make it possible to control one, two, or all
three fluorescent tubes in the light fixtures. Very few people used all three
tubes at once, so only the most-used switch was replaced. Energy savings
are expected to pay for the cost of the new switches in about a year.
Photocell switches sense illumination levels and turn off lights when they aren't needed. Generally, photocells must be hard wired into lighting circuits or built into light fixtures. Different types of photocells are needed for different situations. Have an electrical engineer determine the product that is best for your particular situation. The photocells should be installed by a licensed electrician. Prices vary from $12 to $200, not including installation.
It may not be cost effective to add photocells or occupancy sensors to open office spaces that are illuminated by several banks of lights controlled by a single switch. An occupancy sensor would turn on all the lights even if just one person was using the room. A photocell would turn all the lights on or off based on the light level where it is located. In some cases, the wiring can be changed so that each switch operates fewer fixtures, which may make photocell or occupancy sensor switches practical.
Daylit hallways are particularly good candidates for light control by photocells. Individual offices, bathrooms, and service rooms (such as janitor closets and duplication or storage rooms) are particularly good candidates for occupancy sensor switches. The payoff time for photocells and occupancy sensor switches may be as short as 1 year.
Exit lights are often energy wasters, because they stay on 24 hours a day. If you have old exit lights that use incandescent bulbs, replace them with light-emitting diode (LED) exit signs. Exit signs with LEDs typically use 10 to 50 times less energy than those with incandescent lights. LED signs or bulbs will pay for themselves in energy savings in as little as a year.
LED exit signs are available for as little as $70 through the GSA ($100 with battery backup). Cheaper models are available online and in lighting stores, but be sure they provide enough illumination to comply with your local building codes.
LED bulbs that screw into incandescent light bulb sockets are available for around $30. These replacement bulbs might be a good choice if your incandescent exit signs are in good condition. If you have an exit light that uses a fluorescent tube, it may not be cost effective to change the fixture until it quits working.
Exterior light fixtures can waste energy and a lot of money if they provide ineffective illumination or light things that don't really need to be lit. Take a walk around your site some dark night and note areas with too much or too little lighting, areas that don't need lighting, and areas with dangerous shadows or glare.
Overly bright lighting at night can cast harsh shadows or create glare that prevents people from seeing potential hazards. A more uniform but lower light level may provide more security and safety. Because of the way human eyes work, bluish light provides the best vision at night. Practically speaking, this means that a metal halide or fluorescent (white or bluish) bulb will provide more effective illumination than a much brighter high or low pressure sodium bulb (orange or yellowish) or mercury vapor bulb (usually pinkish, but the color may change over time).
Sodium and mercury vapor lights don't provide very effective lighting, but they are common because they have relatively low initial cost and the bulbs last a long time. Light fixtures using mercury vapor bulbs should be replaced as soon as budgets allow because of their high energy costs and concerns about disposal of mercury in the bulbs. Instead of just changing exterior light bulbs when they burn out, consider converting them to electrodeless induction fluorescent, metal halide, or LED lamps.
Electrodeless induction fluorescent lamps are not commonly available yet, but they should be in a few years. Electrodeless induction fluorescent lamps made by both Phillips and Sylvania have a 100,000-hour lamp life (more than three times the life of sodium or mercury vapor lamps), are extremely energy efficient, provide very good illumination quality, and will start in temperatures as low as –30 degrees Fahrenheit.
Metal halide lamps are common and are a good choice, but they have a shorter bulb life than LED or electrodeless induction lamps. Standard metal halide ballasts won't start in temperatures below 10 degrees Fahrenheit, but cold-start ballasts are available that will work down to about –20 degrees Fahrenheit.
LED lamps are becoming more common. Because the individual bulbs are tiny and cast light in a tight beam, they can be very energy effective for low-light, widely distributed applications, such as a series of lights along pedestrian paths. Depending on the site and fixture selected, energy-efficient exterior light fixtures may pay for themselves in reduced energy and maintenance costs in a year.
Motion sensors and photocell controls can cut energy use for exterior lighting dramatically and in some cases provide better intruder deterrence than lights that are on all the time. Motion sensors may save enough electricity to pay for themselves in as little as half a year.
Light trespass and light pollution are becoming prominent issues. Light trespass occurs when light from a fixture "trespasses" onto a neighbor's property. Light pollution is caused by light shining up into the sky. As an agency dedicated to "caring for the land and serving people," the Forest Service should take these issues seriously. Also, it's not cost effective to pay for electricity to light someone else's property or, even worse, the sky.
If it's not possible to tilt fixtures to focus light where it's wanted, you may be able to add shields or shrouds that reflect or direct light in the desired direction. Shields for some common exterior light fixtures are available commercially for $20 to $200.
- Sources of information about manufactured shields for outdoor lights include the International Dark-Sky Association (http://www.darksky.org/index.php?option=com_content&view=article&id=628) and Outdoor Lighting Associates (http://www.greenearthlighting.com/products.asp?cat=2).
If existing fixtures can't be modified to solve these problems, it may be cost effective to change to a different fixture.
It also may be cost effective to have a lighting engineer who is an expert in energy efficiency evaluate the site and make recommendations about cost-effective lighting changes, both inside and outside.
- The Lighting Design Lab (http://lightingdesignlab.com/) provides inexpensive classes and events and free consultation to Federal agencies in Washington, Oregon, Idaho, and Montana through partnerships with the Federal Energy Management Program and local utilities. Similar programs may be available in other parts of the country.
Financing Operations and Maintenance Energy Improvements
It is usually difficult for Forest Service offices to finance major energy improvements without assistance unless the improvements are part of a capital improvement project. Fortunately, resources are available outside the Forest Service to help finance energy efficiency improvements.
- Detailed information is available at the Department of Energy's Financing Solutions for Federal Buildings Web site (http://www1.eere.energy.gov/financing/federal_energy_managers.html).
Energy Saving Performance Contracts (ESPCs) and Super ESPCs allow Federal agencies to contract with energy service companies to perform energy efficiency upgrades. The service company:
- Conducts a comprehensive energy audit
- Identifies improvements that will save energy and reduce utility bills
- Arranges financing to develop and install energy and water conservation equipment and renewable energy upgrades
The agency is guaranteed that over the life of the contract the combined cost of paying for the improvements added to the new lower energy bill won't be any greater than the energy bill before the improvements. After the contract ends, the agency has a more efficient building or site and much lower energy costs.
This financing option allows agencies to implement energy improvements with little or no initial capital investment. The net cost to the Federal agency is minimal. However, tens of thousands of square feet must be upgraded at once to generate enough savings to make this approach profitable for the service company. Several units may need to work together.
- More information is available at the Department of Energy's Super ESPC Web site (https://www1.eere.energy.gov/femp/financing/superespcs_fda.html).
Another option is the Utility Energy Service Contract (UESC). These contracts are similar to ESPCs, but are handled by the local power company. Under a UESC, the power company typically arranges financing to cover the capital costs of the project. The utility is repaid over time from the cost savings generated by the energy efficiency measures. The agency saves time and resources by using the financing and contracting services that normally have been negotiated ahead of time by the power company. A local power company may be more receptive to small projects than ESPC providers would be.
- A UESC that can be used by any Forest Service unit in the Southern California Edison service area is at http://fsweb.wo.fs.fed.us/eng/programs/facilities/sus_green/excontra.htm.
A UESC may be available in your area, or you may be able to use the UESC with Southern California Edison as an example to negotiate a similar agreement with your power company. An areawide contract may be available through the GSA with your power company.
- Check the GSA Web site (http://www.gsa.gov/graphics/pbs/procuring_energy_R2H915_0Z5RDZ-i34K-pR.pdf).
Most States and many utility companies also have energy incentives or other programs that are available to Federal agencies. These programs vary by State. The programs include: lighting retrofits or other energy efficiency equipment rebates, energy audits, education programs, demand exchange programs, renewable energy credits, incentives for energy efficient construction, peak load reduction incentives, biomass energy equipment subsidies, and technical assistance.
- Visit the Federal Energy Management Program's State Energy Management Programs Web site (http://www1.eere.energy.gov/femp/financing/energyincentiveprograms.html) to find out what's available in your area.
Funding provided by nontraditional sources allowed the Forest Service's Coeur d'Alene Nursery to reduce energy use dramatically by replacing or modifying refrigeration, lighting, and HVAC systems.
- The tech tip, Modern Systems Cut Energy Use 80 Percent at the Coeur d'Alene Nursery, contains information that can help other units reduce energy use and finance energy reduction work. It is available at http://www.fs.fed.us/t-d/php/library_card.php?p_num=0673%202326
Changes in landscaping can be an inexpensive way to reduce energy and water usage and landscape maintenance costs. If done carefully, the changes may pay for themselves in just a few years.
To reduce time spent mowing lawns, the cost of irrigation, and the need for chemical fertilizers and pesticides, switch to Xeriscaping (water-wise landscaping). Xeriscaping uses careful landscape design and plant selection to minimize the need for irrigation.
Your unit's landscape architect can provide plans and advice about making the transition to Xeriscaping. Once established, carefully Xeriscaped areas that use native or adapted species require little to no irrigation or fertilization and become resistant to weeds, cutting down significantly on operations costs.
People associate the Forest Service with landscapes that have a natural appearance (figure 8). Xeriscapes can be designed to conform to those expectations, in contrast to standard suburban or urban-style landscaping.
- For a quick overview of Xeriscaping, take a look
at the Water-Wise Gardening poster (http://www.bouldercolorado.gov/files/Utilities/Water_Conservation/xeriscape.pdf) from the city of Boulder, CO.
- For more information, visit the Colorado Springs Utilities Web site, What is Xeriscape? (http://www.csu.org/residential/environment/xeri/item5935.html) or the University of Georgia's Guide to Developing a Water-Wise Landscape (http://www.caes.uga.edu/Publications/pubDetail.cfm?pk_id=7901&pg=np&ct=Developing%20a%20Water-Wise%20Landscape&kt=&kid=&pid=).
Figure 8—When the McKenzie Ranger District office in
the Pacific Northwest
Region's Willamette National
Forest was renovated, the landscaping
was replaced
with native plants in a setting similar to the surrounding
forest.
The native plants don't need to be irrigated.
Trim vegetation away from structures to ensure air circulation near siding and roofing. Vegetation traps moisture that can cause building materials to fail prematurely. Adjust irrigation sprinklers so they don't spray directly onto the siding or foundation. Overwatering near foundations can contribute to moisture problems inside basements and crawl spaces. Drip irrigation directs all of the water to plants' roots and is a better choice than spray irrigation for plants near a building's foundation.
In areas prone to wildfires, remove dense plantings near structures. They could provide ladder fuels that ignite structures during a wildfire. Replacing or repairing an unnecessarily damaged or destroyed structure uses a lot of resources—not a sustainable practice.
- For more information on improving the fire resistance of structures and sites, visit the National Interagency Fire Center's Protecting Your Home from Wildland Fire Web site (http://www.nifc.gov/preved/protecthome.html) or Colorado State University's Protect Your Home, Forest and Property from Wildfire Web site (http://csfs.colostate.edu/pages/wf-protection.html).
Plant trees at strategic locations to provide shade for structures and reduce cooling costs. In areas with cold winters, deciduous shade trees planted to the south and west of structures will allow light and heat from the sun to enter during the winter when they're needed, but will keep light and heat out during the summer. Plant the trees far enough from the structure that their canopies block the sun but the leaves or needles don't fall on the roof. Shade trees may not be practical in desert climates because of the need for irrigation, but shade structures can serve the same purpose (figure 9). In areas prone to wildfires, trees and shrubs should be a safe distance from structures.
Figure 9—The wraparound veranda in the courtyard of the
Sabino Canyon
Visitor Center in the Santa Catalina Ranger
District of the Southwest
Region's Coronado National
Forest provides shading that keeps the sun
from heating
the inside of the building.
