Hot Water Savings
Americans take hot water for granted, and we still heat it and consume it in fundamentally archaic ways. We burn non-renewable resources - natural gas, fuel oil, propane - to heat water. Incredibly, we then dump the warm waste water out of our buildings and into the environment - wasting at least 75 percent of the water's heat, much of which could be recovered simply and affordably. But it doesn't have to be that way. There are practical and cost-effective strategies available that can provide plenty of hot water, save energy and help the environment all at the same time. Fourteen percent of the average residence's energy use goes toward heating water, according to the Department of Energy. In some areas, such as California, homes and apartments use a third of their energy to heat water. The typical household spends $200 to $500 a year for hot water, depending on household size and the kind of fuel used. In all, we pay about $35 billion a year to keep our domestic hot-water "teapots" perking. Electric water heaters - both direct element and heat-pump - account for about 22 percent of all installations nationwide, according to a 1999 DOE report. Water heaters fueled with natural gas (including LP) account for nearly 70 percent, with much of the remainder operating on fuel oil. Amazingly, less than 1 percent of U.S. hot water service is provided by solar energy, despite improvements in reliability and decreased system cost in the last 20 years. From an environmental and cost perspective, electric water heating leaves a lot to be desired. Depending on the mix of fuels (coal, oil, natural gas, nuclear, hydro and "other") used to generate it, electric power - measured on a BTU basis - gets to your meter with an efficiency of 30 percent or less. Annual fuel utilization efficiency levels have crept up in recent years on equipment fueled by natural gas, fuel oil and LP, but it is still common to find new homes with fossil-fuel water heating that wastes nearly a quarter of the fuel burned. These fuel-fired, low-efficiency water heaters, called "atmospheric units," use a quantity of a home's indoor air to permit the firing of the burner. In tight homes, atmospheric combustion equipment is never recommended. Indeed, it is precluded in some guidelines on "green" building and in quality building manuals from sources such as the Energy Sat, 01 Sep 2001 00:00:00 Bion Howard Bright Lights, Big Savings http://www.smart-homeowner.com/node/8182
Compact fluorescent lamps are gaining market share as prices fall and quality improves.
Home lighting has a dark side: It can waste a lot of energy. American houses contain more than 500 million light bulbs that burn for an hour or more each day. Eighty-eight percent of those lights are incandescent - among the least efficient of all household appliances. Home illumination consumes about 100 billion kilowatt hours of energy each year, about 10 percent of our national residential electricity bill. With electricity costs soaring, there is good reason to rethink how we light our homes and property. But you don't have to waste money to stay out of the dark. Reacting to market demand for smaller energy bills and government conservation programs, manufacturers are producing vastly more efficient bulbs, lighting fixtures and controls. For their part, lighting designers are finding new ways to illuminate houses, in some cases relying more on daylight to cut operating expenses and increase homeowner satisfaction at the same time. Much has been made of compact fluorescent lights, those sometimes fanciful-looking bulbs that can burn for up to 10,000 hours and shave energy usage by 75 percent. They are, in fact, a good way to conserve - especially now that many models have fallen to the $10 range. But there are other advances to consider, too: .Modernized versions of the traditional linear fluorescent tubes are being put to use in places they would never have been found in the past, such as living rooms. These lights offer modest purchase costs, low operating expenses and an extremely long life. .New types of halogen bulbs - a form of incandescent lighting - offer greater efficiency and longer life in such applications as spot lighting, where fluorescents might not work well. .Inexpensive and easily installed controls can turn lights off when no one is in the room, eliminating a common form of energy waste. .Daylighting - in the form of optimized home siting, solariums, skylights and even reflective paint - is bringing sunlight into homes more effectively. Underlying this change is a growing desire among homeowners to reduce the energy they use for lighting. "There has been a fairly dramatic increase in interest in just the past couple of months," said Ivan Beardsley, a principal in the prominent California design firm of Beardsley/Weiss. He cites a surge of interest in the use of color-corrected fluorescent lighting to save energy. "We couldn't give fluorescent lighting away until recently," Beardsley said. Fluorescent lighting has a far greater efficacy - the number of lumens of light created for each watt - than incandescent. An incandescent lamp produces 6 to 20 lumens per watt, while a compact fluorescent can create up to 84 lumens. That adds up to impressive operating savings. Yet fluorescent has until recently been relegated to the kitchen or the basement - partly because of the color qualities of its light, partly for other aesthetic reasons. "Fluorescent has gotten a bum rap - that it buzzes, flickers or makes you look green," said Russ Leslie, a professor of architecture at Rensselaer Polytechnic Institute, in Troy, N.Y., and the associate director of its Lighting Research Center, the world's largest university-based center for lighting education and research. Leslie said advances in technology have overcome those problems. Among the improvements are electronic, or solid state, ballasts - the devices that start the light and regulate the flow of current through it. Older magnetic ballasts could buzz or cause the light to blink; electronic ones eliminate that and allow quicker starts. In fact, electronic ballasts are required for lights with the EPA's Energy Star designation. Coloration has improved, too. Older generations of fluorescent lights produced a blue-green tint that made people look pale and food look unappetizing. While lights with those characteristics can still be found, fluorescents of all types - compact and linear - can be purchased that portray homeowners in a more flattering light. When buying a fluorescent, Leslie advises, look for two things: the correlated color temperature, measured in degrees Kelvin, and the color rendering index, which measures the fluorescent lamp's lighting quality against that of an incandescent. The correlated color temperature refers to the warm or cool ambiance created by the light. A lower number means you'll get warmer reddish and yellowish tones, while a higher number indicates cooler bluish tones. "If you want to match your expectations, ask for 2,700-3,000 Kelvins in color temperature and a color rendering index of at least 80," Leslie advises. The color can be so good that Leslie has designed houses with linear fluorescents in living rooms, dining rooms and bedrooms. These lights, mounted behind valances, wash walls with light, creating a pleasant ambiance and sometimes eliminating the need for table lamps, he said. ∗Linear fluorescents have the added advantage of an even longer life than compact fluorescents, between 20,000 and 30,000 hours. Leslie also recommends looking for the Energy Star rating on fluorescent lamps. It means the light is not only energy efficient, but that it meets appearance standards as well. The compact advantage
Compact fluorescent lights, or CFLs, are capturing an ever-increasing share of the home lighting market, but they've had to overcome obstacles along the way. The first was cost. Priced at about $20 five years ago, compact bulbs now average less than half that cost and have gained acceptance slowly among homeowners who find the 75-cent price of standard incandescent bulbs hard to pass up. Problems with wattage equivalency discouraged some homeowners. Leslie said many manufacturers hurt themselves early on by claiming that dividing incandescent bulb wattage by four or five yielded the wattage in a CFL that would create the same amount of light. When homeowners found that light to be insufficient, a backlash followed. A more reasonable measure is that a standard incandescent bulb - referred to in lighting circles as an A lamp - can be replaced with a CFL of one-third the wattage, according to Leslie. Fluorescent lighting is not a panacea, however, and there are jobs for which it isn't especially well suited. It provides better area lighting than spot lighting, which makes it less effective for downlighting - for instance, in top-hat fixtures often found in kitchens. In those applications, it may be best to use another improvement over standard incandescent lamps: the newest generation of halogens. Halogens are incandescent lamps filled with a halogen to reduce the tendency of the filament to evaporate. Halogen PAR lamps, useful as spotlights, feature a parabolic aluminized reflector for precise light direction and greater efficiency. Even more efficient are halogen IR PAR lamps - which include an infrared coating on the capsule around the filament, which directs heat back to the filament. To demonstrate the possible savings by switching lamp types, the Lighting Research Center offers this example. A room with 12 recessed downlight cans containing 150-watt A lamps costs $233 a year to light, including the cost of replacement bulbs. Switching to 60-watt halogen IR PAR lamps brings the total cost down to $125 a year, with no loss of illumination or light quality. The best advice: use less
If energy reduction is a homeowner's goal, the best approach is simply to turn off the lights. That, of course, is easier said than done, especially in a family setting. But technology can help here, too. Dimmers have long been used to power down lighting in a room; in fact, the newer fluorescents can be dimmed as well, which wasn't always possible with older ballasts. Dimming most types of lamps reduces their power consumption, lengthens their lives and provides homeowners with the ability to change the appearance of a room. Timers are also effective. Much in the same manner as the heat-lamp timers in hotel bathrooms, light timers can be employed in areas such as closets. One of the biggest wastes of energy is lighting an empty room - a common occurrence as residents move quickly around the house. Motion sensors can cut down on that waste. New models of motion detectors can be mounted in a standard wall switch box. A person entering a room switches on the light as usual; if the device senses after a short time that no one is in the room, it will turn the light off. These devices use a passive infrared detection system to detect the narrow band of infrared radiation produced by the temperature of the human body. They are designed to be sensitive not just to IR but to rapid changes in radiation, which is why outdoor motion detectors aren't set off by hot pavement nearby. One byproduct of homeowners' increasing sensitivity to energy use is a desire to keep lighting controls simple. "Five years ago everyone was interested in the kind of house where you arrived at a gate and punched a button and all of the systems came on. Everyone wanted remote control," said Winton Scott, a Maine architect. "I don't hear that anymore. The novelty has worn off." What hasn't worn off is the desire to illuminate homes with as much natural light as possible. Having appropriate natural lighting saves money and adds to residents' appreciation of their home. It can also make them feel better emotionally. However, designers and architects need to be careful to control exposures. Too many windows exposed to too much unshielded sun can make a room unpleasant. That makes the proper use of window shades, landscaping and overhangs important - as is good siting, of course. Leslie said he tries to take advantage of special lighting opportunities in homes he designs. He tries, for instance, to allow sunsets to reflect in certain areas, creating a strong mood. He also promotes the use of light-color paint as a way of helping illuminate a room by reflecting light. "A bucket of paint is the best lighting technology that exists," Leslie said. The desire for natural lighting has led to the greater use of skylights, as well. One relatively new product in that field is the flexible-tube skylight, which allows light to be tunneled through an attic and into interior areas where it's needed, such as halls and baths. These units often are equipped with an electric light mounted inside to provide light at night. Lighting the future
Lighting technology has come a long way in a decade, and much more change can be expected. New types of fluorescents with even greater efficiency are expected to gain ground, and designers are likely to make better use of high-efficiency fixtures and techniques, including task lighting. Some of the changes that are coming could be revolutionary. Manufacturers believe that within a few years light-emitting diodes, or LEDs, will be used in the home for general lighting purposes. Because LEDs are highly efficient, rugged and small, researchers believe they may someday have the potential to replace incandescent and fluorescent lighting in many applications, such as spotlights and under-counter lighting. The leading edge of lighting research may well be OLEDs - organic light-emitting diodes. OLEDs are thin, flexible sheets of electroluminescent material that produce light when current passes through them. OLEDs consist of three layers of material: an organic or polymer film between two sheet electrodes, one of which is transparent. The middle layer generates light when current is applied, and that light shines through the transparent electrode. Although OLEDs are still in the development stage, researchers believe the day will come when rooms and hallways are covered with them - in effect creating lighted wallpaper that will fill spaces with light using very little power. Whatever technology they employ, the task for lighting designers will remain constant: making people happy in their surroundings. "Lighting has to do with values and image," Leslie said. "It can make people comfortable, or it can make them uncomfortable."
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