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A Green, Well-Lighted Place

How to choose energy-saving lighting for an eco-friendly house

energy efficient green lighting
Photo by Mark Weiss
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The most successful green buildings must also be comfortable and attractive, and the right lighting can make all the difference in getting them to feel this way. But good lighting and sustainable design are not mutually exclusive, as we showed recently at This Old House TV's Austin project, the green model of a 1926 Craftsman bungalow.

As an architectural lighting designer specializing in sustainable buildings, I was invited to join the team working on the TOH project. Although my New York and New Haven-based firm most often consults on large-scale commercial and institutional buildings in the Northeast, I jumped at the chance to work on a wonderful renovation in my old Hyde Park neighborhood in my hometown of Austin.

Homeowners Michele Grieshaber and Michael Klug had very clear ideas about what they thought their new lighting should be like. They wanted their 1926 Craftsman bungalow to glow warmly, but be technologically sophisticated, well-lighted, energy-efficient, and environmentally responsible. Sounds like a tall order, but it turns out that wasn't hard to do, as long as we applied some thoughtful design while keeping in mind what was actually available in the current technology. To do that, we used certain techniques that can be applied to green lighting in any home.

Sustainable lighting design means making sure the visual environment is excellent, but at the same time minimizing the impact on the natural environment. Different situations will require different approaches, so there is no single prescription for quality lighting. But the first step is always understanding how a space will use a balance of ambient, task, and accent lighting. Once that is decided, there are many ways to achieve the design using environmentally friendly light bulbs, fixtures, and controls.

Lighting's biggest environmental impact is energy consumption. I always start with the light source, known as lamps in the lighting industry, but commonly called light bulbs. Knowing the right type and amount of light needed, then selecting the most efficient source provides the most sustainable and energy-effective solution.

Ratings
Although the wall of blister-packed lamps at your local home improvement store may seem a little intimidating, there are some simple metrics you can check to choose what's best for your design. Lamp performance is measured in five basic ways:
1. Lumens, which indicates light output.
2. Lumens per watt, which indicates how much light is produced for the energy used. This measurement shows how efficientl the different types of lamps are.
3. Color temperature (measured in Kelvin degrees), typically going from 2700K warm white to 4100 cool white.
4. Color rendering index, expressed in a number from 0 to 100, with a 100 CRI rating indicating a full-spectrum light source.
Lamp life, rated in hours of average expected life before burn-out.

The most successful green buildings must also be comfortable and attractive, and the right lighting can make all the difference in getting them to feel this way. But good lighting and sustainable design are not mutually exclusive, as we showed recently at This Old House TV's Austin project, the green model of a 1926 Craftsman bungalow.

As an architectural lighting designer specializing in sustainable buildings, I was invited to join the team working on the TOH project. Although my New York and New Haven-based firm most often consults on large-scale commercial and institutional buildings in the Northeast, I jumped at the chance to work on a wonderful renovation in my old Hyde Park neighborhood in my hometown of Austin.

Homeowners Michele Grieshaber and Michael Klug had very clear ideas about what they thought their new lighting should be like. They wanted their 1926 Craftsman bungalow to glow warmly, but be technologically sophisticated, well-lighted, energy-efficient, and environmentally responsible. Sounds like a tall order, but it turns out that wasn't hard to do, as long as we applied some thoughtful design while keeping in mind what was actually available in the current technology. To do that, we used certain techniques that can be applied to green lighting in any home.

Sustainable lighting design means making sure the visual environment is excellent, but at the same time minimizing the impact on the natural environment. Different situations will require different approaches, so there is no single prescription for quality lighting. But the first step is always understanding how a space will use a balance of ambient, task, and accent lighting. Once that is decided, there are many ways to achieve the design using environmentally friendly light bulbs, fixtures, and controls.

Lighting's biggest environmental impact is energy consumption. I always start with the light source, known as lamps in the lighting industry, but commonly called light bulbs. Knowing the right type and amount of light needed, then selecting the most efficient source provides the most sustainable and energy-effective solution.

Ratings
Although the wall of blister-packed lamps at your local home improvement store may seem a little intimidating, there are some simple metrics you can check to choose what's best for your design. Lamp performance is measured in five basic ways:
1. Lumens, which indicates light output.
2. Lumens per watt, which indicates how much light is produced for the energy used. This measurement shows how efficientl the different types of lamps are.
3. Color temperature (measured in Kelvin degrees), typically going from 2700K warm white to 4100 cool white.
4. Color rendering index, expressed in a number from 0 to 100, with a 100 CRI rating indicating a full-spectrum light source.
Lamp life, rated in hours of average expected life before burn-out.

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Lamps

 

Lamps

The most common screw-in incandescent lamp is cheapest to buy, but can be much more expensive to operate in the long run, compared to a more efficient lamp with the equivalent lumen output. An incandescent providing comfortably warm 2700K, 100 CRI light only puts out about 20 to 25 lumens per watt and lasts 750 to 1,000 hours. A slightly more efficient halogen lamp with crisp 3000K, 100 CRI light produces about 30 lumens per watt and lasts about 2,000 hours. But, a screw-in compact fluorescent with an integral electronic ballast has a nice 3000K color temperature at a much better 60 lumens per watt with a rated life of 5,000 hours or better. In other words, a compact fluorescent uses a third of the energy and lasts five times longer than the typical incandescent light bulb.

The downsides of compact fluorescents are that they cost three to five times more than incandescent lamps, don't always fit in decorative fixtures, and some people find their light quality slightly lower. But from an environmental perspective, this simple lamp conversion in places where the color is less important'in downlights, closet lights, porch lights, and such'can translate into long-term energy savings and environmental benefits. And, linear fluorescent and pin-based compact fluorescent lamps'more commonly used in commercial buildings'perform even better. Despite the fact that all fluorescent lamps require a trace of mercury to operate and should be properly disposed or recycled, the energy saving benefits far outweigh the mercury issue. The less energy used, the less greenhouse gas produced by power plants.

Looking a little into the future, LED (light emitting diodes) lighting is something to watch. Although much more expensive right now than other light sources, this solid-state technology is notable for its ability to produce attractive white light at about 100 lumens per watt lasting 50,000 hours or more. Researchers predict that within the next few years, affordable consumer-grade 'white' lighting products will approach 200 lumens per watt efficacy.

Controls and Placement
Along with energy efficient sources, it is important to consider lighting controls as a great way to provide lighting flexibility as well as additional energy savings. This can range from a simple dimmer, to sensors that make sure the a light goes off when no one is in the room, to fully programmable systems tied in with a home security or entertainment system. The most efficient light is one that only gets turned on when it's needed and turned off when it's not.

Going outside, it is important to avoid light pollution and light trespass caused by unshielded outdoor lighting. Light pollution or 'sky glow' has become an important public awareness issue, as is unwanted glare or light trespass problems for neighbors. The environmental approach is to use well-shielded 'cutoff' fixtures, rather than floodlights and wall packs that emit light that points above the horizontal toward the sky. This is also energy-efficient because upward lighting (except for intentional and well-focused landscape lighting) is just wasted energy.

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Fixtures

 

Fixtures

Beyond energy efficiency, I concentrate on fixture quality and efficiency to get optimal lighting performance. Using well-made, high-efficiency fixtures requires the fewest units to get the right amount and quality of light. But I also check on the environmental commitment of the manufacturers. With hundreds of to choose from, I give preference to those that demonstrate commitment in their product literature and websites to energy conservation, recycling programs, and environmental management initiatives.

This usually means that I recommend the 'big names' in lamps and fixtures because those high-profile companies have to take those responsibilities seriously. But I also like to work with smaller specialty or local manufactures to make sure the project gets the best equipment and travels the least distance to the site. In the case of our the Austin project, architect David Webber introduced me to Two Hills Studio in South Austin. They were able to translate our decorative fixture aspirations into locally-crafted metal and glass chandeliers, pendants, and sconces that use a selection of halogen and compact fluorescent lamps. This beautifully satisfied our goals for a warmly glowing home with a smart approach to energy conservation, by using sustainable lighting techniques and technologies to fit the owners' expectations.

Mark Loeffler, IALD, LEED is an associate director of Atelier Ten, an environmental design consulting firm with offices in New York, New Haven, and Baltimore. A professional member of the International Association of Lighting Designers and a LEED accredited professional, he leads Atelier Ten's lighting design practice.
 
 

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