• Integrate the daylighting scheme into the architecture
• Integrate the daylighting scheme with building systems

These final two points remind us that architecture is synergistic, that is it becomes more than the sum of its parts. They tie the entire daylighting strategy together and their implementation can make or break a design.

Integrate the daylighting scheme into the architecture

Daylighting provides an excellent opportunity to give intentional and unique form to a building. The north, south east and west façades of the building are all in need of different daylighting strategies. This makes it easy to create a solution that is eclectic. At the same time it gives the opportunity to create a dynamic façade that is consistent in fundamentals yet different in the details.

Integrate the daylighting scheme with building systems

Last time we touched on daylight controls. Integrating daylighting systems with building systems goes beyond simple controls. It also has to do with the difference in the color temperature of daylight versus that of electric light. To improve the cohesiveness of the lighting design it is important to specify lighting that is compatible with natural light.

Since reducing electricity use is one of the reasons for incorporating daylighting into a building it is important to have simple controls that dim or switch off the electric light when it isn’t needed. Simple controls are easy to repair or replace and contribute to the success of a daylighting strategy.

Lastly the combination of daylight and supplemental electric light provide an opportunity to reinforce a particular lighting strategy or to play off of it. Realizing the passage of time is a side effect of using natural lighting solutions. This passage of time creates an opportunity to differ the electric lighting strategy in the morning, evening and night to help reinforce the passage of time, something that many occupants are missing in modern buildings.

Originally posted 2010-03-20 00:01:20.

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• Assess lighting needs for typical visual needs
• Use of apertures to create focus and mood

These two components are somewhat advanced strategies the breathe life into the space and make it more dynamic, all with out resorting to electrical lighting for the majority of the day.

Assess lighting needs for typical visual needs

Daylighting must address the needs of the visual task that is to be performed within the space. The lighting level needs of an occupant vary between warehouse space and office space. Therefore the amount of light provide by the daylighting strategy must be also vary.

Placement of the daylighting aperture and its controllability are critical. The quantity and quality standards set forth by the Illuminating Engineering Society of North America (IESNA) is applicable to daylighting and is a great resource.

It is also good to keep in mind that the best daylighting strategy may need supplemental electric task lighting as well. This is particularly true in early morning and evening situations.

Use of apertures to create focus and mood

The use of natural light to illuminate a space doesn’t mean that the light levels need be uniform throughout. With special consideration of the size and placement of apertures, daylight can be directed to accentuate a design, indicate important spaces and act as a wayfinding strategy within a building. Scale models and digital models are excellent tools in exploring different strategies.

Another aspect to these apertures is that they can perform double duty. An efficient lighting solution can be incorporated so that in the evening and night the same visual impact is created. Light sensors ensure that the electric lights only come on when light levels dip below a predetermined threshold.

Next time we will wrap up with the final two components: integrate the daylighting scheme into the architecture and integrate the daylighting scheme with building systems. See you then.

Originally posted 2010-03-16 00:05:25.

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Light Pollution: An Overview
Light pollution is any adverse effect of artificial light including sky glow, glare, light trespass, light clutter, decreased visibility at night, and energy waste. Denver suffers from serious light pollution caused by uncontrolled light directed up toward the sky. The good news is that light pollution is, in many cases, easier and less expensive to remedy than other types of pollution. And the changes can begin with your own choices about exterior lighting at night.

Examples of Light Pollution
A great example of light pollution is a post-top lantern, often nostalgic in style, which emits light in all directions. Standard "cobra head" streetlights, though they have an opaque top, emit light above a 90 degree angle, which means that they are not Dark Sky compliant. Another is billboard lighting that aims upward. A common residential offender is a lantern style fixture in which the bulbs are visible and the light escapes in all directions.
For local light pollution, look no further than 6th Avenue west of downtown. The floodlights between the access road and 6th Avenue mounted on poles, with regular "cobra head" streetlights below are much brighter than necessary, poorly positioned to light the road, and are a source of glare to drivers as well as the people who live nearby. Driving the Denver metro area, look for these "glare bombs" and post their location in the comment section at the bottom of the article. They're everywhere.

Why Is Light Pollution a Problem?
Remember lying in the grass as a child and looking up at the stars? Our children in Denver, as well as those of us who enjoy stargazing or taking in meteor showers, like November's Leonid shower, are missing out on that opportunity. Much more serious implications of light pollution include disruption in human circadian rhythms, sleep cycles, and immune system function, as well as a deleterious effect on animal reproduction. In addition, light directed at the sky is, in all cases, a waste of energy, no matter how exciting it appears. A closer look at the links between light pollution and human health issues will be explored in the other articles in this three part series.

How Can We Make It Better?
In an ideal world, we would no longer attempt to mimic the glow of daylight in our night time world, and instead, would lower all ambient light levels since the dark-adapted eye needs much less light than a bright-adapted eye in order to see.

Here's the good news. As individual citizens, we can make exterior lighting choices at our homes and workplaces that do not further light pollution. The International Dark Sky Association, which is dedicated to preserving dark skies and pushing for legislation to enforce dark sky compliance in communities, has published a list of fixtures that can be used in all types of outdoor applications without lighting up the night sky, angering neighbors, or wasting energy. Let's explore some common elements.

1. Assess your requirements. Determine where you really need light. Don't use light as "decoration" or for visual effect at night.
2. Direct light where it is needed. Remember that at night, less is more. Concentrate fixtures only where needed. Choose fixtures that can be aimed, and keep them aimed toward the ground.
3. Avoid glare. Glare actually compromises safety, as it can render an attacker or intruder invisible. Glare is often caused by an unshielded source, such as a fixture where the bulb is visible.
4. Use lower wattage bulbs. More light does not mean more safety. The dark adapted eye can best see at night when there is uniformity of illumination. A bright light against a dark background causes pupil contraction, so the dark background beyond the bright light is invisible.
5. Use "full cutoff" fixtures, which means that less than 1% of their light output is emitted above 90 degrees from horizontal.
6. Make sure that the light source is not visible when viewing the fixture straight on.
7. Keep in mind the motto "Lights Down, Stars Up".

For some Dark Sky compliant light fixtures, check out the International Dark Sky Association's approved fixtures or Skykeepers.org approved fixtures. Both websites are filled with information about dark skies and how to take action to minimize light pollution.

Resolve this year to take action on behalf of keeping our skies dark. Think of light pollution as light leak. If light fixtures were water faucets, and any light emitting toward the sky was a drip, we'd fix it immediately. Let's address light pollution with the same zeal we apply toward other matters of sustainability and energy waste, and encourage those around us to do the same. If your neighbors have bright lights that shine into your bedroom at night, check out this great resource on how to address the topic with diplomacy.

In the next two articles in our three part Dark Sky series, we'll address more specifics on fixture selection and how light exposure at night affects our health.

Originally posted 2010-02-07 00:01:34.

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Many attendees are watching the industry closely to see innovative product solutions, particularly LED's. This year did not disappoint.  While many manufacturers have shown LED luminaires and lamp (bulb) replacements in previous years, the industry is making enough progress that more of these solutions are nearing readiness for widespread use.

At the LFI Innovation Awards, a new LED module from Bridgelux and Molex won the Most Innovative Product of the Year Award.  Helieon is an LED light source that turns and locks into place, emulating traditional lighting sockets and allowing users to alter beam angle, color temperature or light output without removing or replacing the luminaire.

“Bridgelux is delivering energy-efficient LED lighting solutions that are driving the transformation of the $100 billion lighting industry,” said Bill Watkins, Bridgelux CEO. “Providing high quality light and an easy, familiar installation experience at a price point to enable mass adoption, Helieon delivers on the promise of solid state lighting.”

This year's LFI showcased a number of solutions from manufacturers that bring the promise of LED lighting for general illumination closer to reality.  Viable site and exterior lighting solutions, as well as  linear and point source luminaires for interior use boast increased lumen output, better controllability, better color rendering, and lower costs than in previous years.

The lighting industry continues its endeavor to deliver viable, affordable LED-based solutions for general ambient light, a need which has typically been filled by fluorescent and incandescent lamps.

Originally posted 2010-08-26 00:01:04.

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LED Site lighting with photo and occupant sensor

Not only is the lighting itself provided by an LED array, but the control of the light uses both a photosensor to ensure that it doesn't come on during daylight hours, and also an occupant sensor so that the site is only lit when it is occupied. This not only provides benefits of low electrical usage for the lighting, but also less light pollution at night as the lights only come on when they are necessary for users of the campus.

LED Outdoor Lighting at NREL

These ideas have been a long time coming, and it's also great to see such fresh and innovative designs for the fixtures themselves. The ability to save on site lighting loads is incredible, and further helps achieve LEED points on sites that are otherwise driven by their exterior site lighting requirements.

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Projected Light Over the Depth of the Entire Office

The Transom has the effect of having Venetian Blinds in it (and the cost is about the same) while the incident light is capable of being reflected to the furthest reaches of the depth of the office. In fact, during our tour, the only artificial lights we could find that were on were over areas with taller partition walls that were separated for privacy.

Transom with Reflective Louvers for Effective Daylighting

The ceilings in the space are painted with a bright light surface as well as the acoustic panels in order to take the reflected light and distribute it more evenly throughout the room.  In the end analysis, an elegant and simple solution that creates a wonderfully naturally lit indoor environment.

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3. Controlling Western Sun Glare with Electrochromic Windows at NREL

To be used in applications where there are great views (and as a result, glazing) to the West, which is extremely common in the Denver and front range area, the problem of handling afternoon heat and glare has a technological solution - Electrochromic Glass. This glass essentially has a thin film between the layers, that when stimulated with an electric charge, actually changes its transmittance of visible light.

Electrochromic window immediately after turning on

The amount of energy necessary to provide the stimulus is extremely small, according to our NREL guides, and the reduction in thermal gain and visible glare is significant. The transformation takes a few minutes to experience, and the tinting emanates from the electrode line outward until the entire window is evenly tinted.

Electrochromic window a few minutes after start

The window tinting can be controlled using photosensors that detect the direct light in order to automate the system and eliminate the need for tinting at inappropriate times of day or on cloudy days. According to our guides at NREL, the cost of this glazing is approximately twice that of a conventional glazing system, and when factoring in the initial and life cycle costs of various other systems that would be necessary to combat the effects of the western sun, is easy to justify.

Fully Tinted Electrochromic Window Adjacent to Door With Standard Glazing

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Understanding Net Zero involves a number of key points. The first is a focus on reducing the energy demands of the building. This is achieved by both a shift in culture and how we're used to living/working as well as advanced technologies for reaping the highest efficiencies out of every aspect of the building. After this disciplined reduction in demand, the remaining energy use must be provided with renewable energy. Additional technologies are utilized to provide this power, such as Photovoltaics (PV) or Wind Power and the building must be rigorously modeled in order to demonstrate that all of its energy needs are provided for by its own energy production.

Below is a breakdown of the energy use in a typical Office Building in the United States. As you can see, reducing the loads is the first step in a Net Zero design strategy, and is the primary focus of this article.

Typical Energy Consumption In US Office Building - Courtesy of US Energy Information Administration

Below is our top ten list of effective ways to reduce energy demand in an effort to approach Net Zero:

10.) High efficiency HVAC systems. This seems obvious, but you would be amazed at the spectrum of systems available on the market today. A net zero building relies on the best of the best of these systems. Heat Recovery Ventilators should provide fresh air ventilation without releasing valuable heat to the exterior of the building. Sophisticated control systems are also necessary to manage the building HVAC system to respond to the changing needs of the building and the occupant load.

9.) Daylighting. The development of large commercial buildings often leads to vast amounts of enclosed space with no access to natural daylight. Artificial lighting creates a huge burden on the energy demand and must be balanced with as much natural daylighting as possible. This is especially relevant for buildings that operate primarily during daytime hours

8.) Artificial Lighting and Controls   High efficiency artificial lighting sources are a crucial supplement to daylighting. While daylighting should be a primary light source (with appropriate shielding and redirection), artificial lighting must be carefully considered for night time use, in interior spaces, and to supplement daylighting.  High efficiency fluorescent and LED sources can be combined with judicious use of ceramic metal halide and halogen sources.  It's important to work with the Client to adjust expectations for artificial light levels in Net Zero energy buildings.  Certain older recommendations for foot candle levels from artificial light are very difficult to attain in Net Zero buildings.  Supplementing overhead or ambient light levels with individually controlled task lighting is a way to keep light where it's needed and minimize energy use.  Just as important as efficient sources are controls that manage use of artificial light loads. At a minimum, commercial buildings striving for Net Zero energy must utilize daylight sensors to tune artificial light levels based on presence of daylight; and occupancy sensors to turn off lights when spaces are not used. Other controls that should be seriously considered include a building energy management system; and plug load occupancy sensors for non-critical plug loads.

7.) Passive Solar heating/cooling. Depending on the site location and orientation, all measures must be made to draw available solar heat into the building in Winter months while shading during Summer months in colder or temperate climates. In hot or humid climates, shading and protection from inviting unwanted heat into the building is critical to reducing cooling demand. Window specifications are critical to the success of a passive solar design, and these specifications are different for differing exposures within the same building.

6.) Sustainable Trees. The landscape design for a Net Zero building is critical in managing the microclimate around the building. Landscaping can provide shade trees to protect the building from unnecessary heat gain. Trees can also control unwanted winds that could create unnecessary heating demand in colder temperatures.The landscape design should also require the minimum amount of energy to maintain and operate.

5.) Rooftop gardens and living wall systems. Also a huge buffer to managing the building's thermal envelope are rooftop gardens and living wall systems. These are natural solar devices which convert much of the sun's energy to plant life rather than introducing it into the building. Careful integration of these systems into the design is key to managing building temperatures, but they should not add to the loads of the building in order to maintain.

4.) Thermal Storage. In climates that endure temperature swings, there is an opportunity to retain and store heat provided for during the day that can be released at night. Methods include thermal mass walls and newer technologies include phase change materials that are capable of storing significant amounts of heat energy at near-room temperatures. Other methods of thermal storage can provide heat for domestic hot water within the building, and should be considered in the design.

3.) Natural Ventilation. We have all been in buildings that are sealed with no ability to open the windows. While this was the historic solution to balancing and controlling HVAC systems in buildings, it eliminates the ability to heat and cool interior spaces naturally  and with the informed decisions of the occupants in a temperate climate zone. Including natural ventilation into a larger building is arguably more complicated for the mechanical engineer, but the results are less energy demand and greater occupant comfort if done correctly.

2.) Superperforming thermal envelope. The old mantra of R-value is not the only test anymore of assembly performance. Every mode of heat transfer must be addressed in every wall, roof, floor, window, door, duct, shaft and penetration. Controlling conductive, convective and emissive heat transfer is critical to controlling heating and cooling loads in a building. New systems involving spray foams and low-e materials are necessary in any Net Zero building.

1.) Adjustments in culture and expected use. No one is asking to return to the turn of the last century and compromise internal occupant comfort, but there are some things we've gotten used to that are really unnecessary energy consuming items.  Is it necessary to keep lights on in unused spaces during business hours and does the HVAC system need to run 24/7 in every space? Appliances should be assessed for their necessity and reduced to meet the real need of the building functions. Necessary appliances should be high efficiency, reducing energy consumption. Some things that we've gotten used to are not only unnecessary, but also can contribute to occupant discomfort. A net zero building relies on a culture shift of its occupants to be mindful of the energy use that is being consumed. Employee training programs and proper operating and maintenance procedures for all users of the building are critical. This is hands down the best way to address plug loads, which are the most difficult to quantify and model in any Net Zero design.

Not all building types have the same energy needs. It is important in every project to assess the specific needs for the building type and its occupants. Below is a chart representing the electricity consumption of various building types. The reduction methods outlined above are relevant to all of these building types, but would be tailored to specifically meet Net Zero design goals for each project type. Note that this chart is for electricity only, and does not represent total energy use.

Electricity Consumption per Square Foot by Building Type - Courtesy of US Energy Information Administration

EVstudio is involved with a wide array of sustainable buildings that we have designed. There are many methods for gauging the sustainability of a building. The most popular these days is through the USGBC LEED program. However, one can design and build a Net Zero Building without ever going through the LEED process. For more information or to discuss how your project could be Net Zero or LEED certified, please contact us by commenting on this post below, or through the contact information on our website and we would be happy to discuss.

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Perception of light level also depends on the color temperature. The more blue-white the light, the higher the perceived light level, even when foot candles are the same. Warmer color temperatures are often perceived as a lower light level. This is useful when considering task versus ambient light; cool task lighting can provide more visually perceived light (helping the care provider), while slightly warmer ambient light can feel less intimidating (helping the patient).

High levels of contrast tend to portray excitement, but in the medical environment, can cause confusion for patients with aging eyes, and work against eyes of all ages as the eye's adaptation from dark to light takes time, and decreases with age; thus, the lower light level areas often feel dark, and the higher light level areas, painfully bright. We should strive for good uniformity in the medical care environment, especially at low light levels.

In a patient care setting, we need to consider two very different needs and experiences.

First, let's consider the needs of the care provider. There must be adequate light to examine skin color and texture, and shadows are important to see variation in skin, depth of lesions, etc.! That means that totally indirect light sources don't work for care providers doing critical exams unless there's also daylight. 3000-3500K (halogen color temperature) is typical, but I believe it's wise to mockup exam rooms with color temperatures ranging from 3000-4100K and let the practitioners give input on their preferred color temperature. It's feasible to have a portable exam light or local task lights such as recessed ceiling fixtures that are on during the critical part of the exam. The rest of the time, these lights do not necessarily need to be on.

Second, we must consider the patient experience. Indirect, lower level lighting that is warmer in temperature offsets the perception of a sterile, institutional exam room. With reasonable uniformity, the light levels won't seem low to the patient while they're waiting for the practitioner, and during any initial discussion. For patient purposes, low level 100% indirect light, like fluorescents over the exam cabinets reflecting onto a white ceiling, are soothing.

Let's not forget context. Corridors and halls are often dreadfully overlit. Realistically, between 5-15 footcandles, depending on the users, can get the job done, especially with good uniformity. When you go from a corridor that has 5-10 footcandles to an the adjacent space with 25-30 footcandles, the perception is WOW! This place is well lit! However, when you have 30 foot candles in the corridor, an exam room with similar average illumination feels dim, especially if that light is all on horizontal surfaces. By sensitivity to context, we increase the perception of brightness by keeping adjacent spaces at a lower light level as much as feasible.

We also need to consider the light reflectance value of the space's finishes. Lighter colored finishes create more of an overall perception of brightness.

As with all well-designed lighting solutions, there is not a one-size-fits-all approach.  We need to provide flexibility in controls that allow the lighting to be used in varying capacities, such as during the critical portion of an exam, versus when the patient is awaiting the care provider's arrival.  Flexibility and user control has been proven to decrease energy consumption and increase user satisfaction.  For that to be successful, the users must be "active users" and engage with the capabilities designed into the lighting system.

Originally posted 2010-07-22 00:42:23.

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Virginia, you've experienced one of the main issues with compact fluorescent bulbs that we can easily avoid with some education.  Be prepared to carefully scrutinize the packaging of bulbs you're evaluating, and keep in mind the following guidelines.

First of all, we must consider two rating systems currently used by the lighting industry to determine what color a bulb is relative to known sources such as incandescent bulbs or daylight, and just how real that bulb makes things look compared to a known source.

1. Correlated Color Temperature, or CCT, defines the warmth or coolness of a light source, and ranges from about 1,800 degree Kelvin (1800K) for a candle to a very cool north sky at over 20,000 degrees Kelvin (20000K). Our benchmarks are an incandescent bulb at 2700K, direct sun at 5300K, sun with blue sky at 6000K, and north sky at about 10000K.  Many offices and commercial spaces are lit with fluorescent bulbs that are 3000K or 3500K, which look cooler than an incandescent bulb.  Fluorescent bulbs labeled "warm white" are typically 3000K, while "cool white" bulbs are typically 4100K. Check out different color temperatures here.
2. Color Rendering Index, or CRI, ranges from 0-100 and indicates how colors appear relative to two benchmarks: incandescent bulbs, including halogen, and daylight. These both have CRI's of 100.  The closer to 100 the CRI is of a light source, the more natural and rich colors tend to appear.  Many newer fluorescent sources have a CRI above 80. Read more about CRI here or here.

The key to picking a compact fluorescent bulb requires carefully scrutinizing the packaging for information about color temperature (sometimes noted as CCT, if it is labeled at all) and color rendering index (almost always referred to as CRI). A recent trip to several local purveyors of compact fluorescent bulbs turned up mixed results: packaging sometimes indicated color temperature, sometimes did not.

Stick with products that label color temperature, which usually shows up on the packaging simply as "2700K", or in the product number with a number like "827". This is lighting industry parlance for a product that has a CRI in the 80's (hence the 8), and has a CCT of 2700K (hence the 27). Other likely combinations are 830 (CRI in the 80's, CCT of 3000K), 835 and 841.

Consider testing results from independent laboratories. In rigorous testing of color accuracy and color shift conducted by the Lighting Research Institute at Rensselaer Polytechnic Institute, compact fluorescent lamp color from Philips, Osram Sylvania and GE was more accurate with less color shift over time than products from SunPark Electronics of Lights of America.  See the test results at the end of this report.

Here in the mountain west, our light tends to be pretty warm, and an environment filled with dusty sage, buff and terra cotta looks most balanced with a warmer color temperature like 2700K - 3000K. One of the Denver Lighting Examiner's preferred compact fluorescent bulbs is Osram Sylvania's Living Spaces, which has enriched red color intended specifically for living environments, color temperature of 2700K, CRI of 82, and energy star rating. They are available locally at Lowe's.

Choose what color temperature is best suited to the intended use and desired feel of a space. Want a room to feel cool and conducive to intense concentration? Choose a cooler color palette with grays and blues and bulbs with a cooler color temperature, like 3500K.  Want to feel enveloped in warmth, soothed, and comforted, like you're curled up by the fireside or at your favorite restaurant under dim light?  Choose our warmer palette of buff, rich browns, and reds, and bulbs with a warmer color temperature of 2500K-2700K.

Originally posted 2010-02-16 00:01:41.

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