City of Seattle Department of Planning & Development Technical Brief .seattle.gov/dpd/greenbuilding n i d l i u b n e e r g / d p d / v o g . e l t t a e s w. w w environment." Visually effective andappealing, lighting highquality of thevisualenvironment onthenatural withtheleastimpact sustainable lighting design as"meetingthequalitative needs the InternationalAssociation ofLighting Designers (IALD) define (IESNA) America and of North The Engineering Society Illuminating cause glare andoverheating. rays thedirect light inaspace ofthesunwhichcan whileblocking the available to provide light ofthesky appropriate levels ofdiffuse daylightbuilding during hours. At itscore, itisaprocess ofbalancing illuminatingfor theinterior spaces offunctionally ofa thepurpose Daylighting isthestrategy ofproviding access to thelight ofthesky environment withsubstantial energy savings. visual engineering team iscrucialto achievingthehighest-quality integrated relationship between Architect, Lighting Practitioner and Lighting isintegral design. Adeeply to highperformance to supportthecriticalfunctionsofafirestation. appropriate, andenergyefficientindoorenvironmentinorder respond todaylightandprovidethehighest-quality,visually patterns ofuse-withintegratedelectriclightingdesignedto an architecturaldaylightingresponsetosite,climate,and arcofanintegratedlightingstrategydemands The fundamental Lighting Integrated is What Integrated Lightingfor Fire Stations: Daylighting and Electric Daylighting andElectric Lighting Strategies create abetter environment for the “The natural daylighting,“The improved heat from passive solargainwill Image courtesy Samaha Associates Samaha courtesy Image firefighters whousethestation indoor air quality andradiantindoor airquality Tom Lee, Associates. Samaha 24 hoursaday.”
provides the greatest environmental and n Ensuring system flexibility, economic value for all project types. maintainability, durability and The basic goals of sustainable lighting controllability. design include: n Providing for proper monitoring and n Using daylight as the primary source of commissioning illumination The integrated design process is changing n Minimizing the use of energy through an the traditional roles and relationship integrated design that includes effective of the Architect, Lighting Designer, controls Electrical Engineer, and Manufacturer. Including lighting design considerations n Avoiding skyward illumination to reduce at the beginning of a project allows for light pollution sustainable design goals to be more n Specifying environmentally-preferable thoroughly addressed and successfully materials and equipment and managing achieved. their disposal to reduce their end-of-life environmental impact.
Benefits of High Performance Lighting
The visual needs of building occupants are atmosphere, visual comfort, and judge complex and involve emotions, actions, the aesthetics of a space, determines how perception and health, all influenced by we feel about working and living in this lighting. From visually locating objects space. Lighting based upon human needs to the speed and accuracy of doing tasks, is central to making a fire station function lighting is central to how people function as a place of precise, efficient and accurate within a space. In addition to the functional visual work, while also being a welcome aspects of lighting, the emotional and visual respite from the enormous stresses perceptual aspects are equally important. placed upon firefighters. The way we perceive the mood and
Health Benefits
The health benefits of daylighting can lead to higher worker satisfaction, reduced produce positive effects for the health and health problems, and lower absenteeism as wellbeing of all building occupants. Recent well as a richer daily experience for workers. studies indicate that day lit environments
Circadian Rhythms
"Circadian rhythms are regular changes in A well day lit space can help maintain mental and physical characteristics that normal circadian rhythms. In the fire occur in the course of a day (circadian is station environment where a normal sleep Latin for "around a day"). Most circadian schedule is regularly interrupted, circadian rhythms are controlled by the body's rhythms can fall out of synch, which biological "clock." - Healthlink, Medical may cause problems with concentration, College of Wisconsin. alertness, and overall wellness. Providing
2 city green building quality daylight balanced with appropriate by creating light at night that is emitted darkness at night can help regulate the at certain non-intrusive wave lengths circadian system leading to improved (typically toward amber light) and by mental health and increased readiness. creating quality darkness for restful sleep. Daylight and views can decrease stress and All these benefits are vital to the firefighters have a calming effect on occupants of a who must be alert at a moments notice. building. Additionally, improved health of fire Well designed electric lighting can help station occupants means a reduced cost in support the wakefulness of occupants by insurance premiums to the City and fewer creating lighting that does not disturb accidents so that the fire station performs the hormonal melatonin response of better. the circadian system. This can be done
Visibility
Good visibility is critical for the functions of offset visibility losses due to age or other an effective fire station. An understanding vision factors. Using diffused daylight and of contrast, luminance, time and size are mitigating contrast from glare and shadows critical variables to good visibility. Age can provide higher levels of visual acuity. changes these variables; for the older This causes less eye strain and allows for occupant, the task must be larger and more accurate performance of visual tasks. brighter and its contrast higher in order Both are important to a team of firefighters to achieve visibility levels equivalent to preparing their equipment for the next younger occupants. In general, higher emergency. contrast and improved lighting can help
Task Performance
Lighting must enable occupants to perform reports in the office, preparing meals their work quickly with few or no errors. and relaxing. Each of these tasks requires The range of tasks includes: cleaning different illumination requirements. and inspecting equipment, writing office
Mood and Atmosphere
The need for a distinct change in visual Carefully planned lighting and interior atmosphere from the functional Apparatus design can facilitate adaptation in these Bay to the relaxed feel of the Dayroom is different spaces with varying in mood and critical for creating a space that functions atmosphere. both as a home and as a work environment.
Emergency Operations
Using light to make the environment safe operating environment for the firefighters for quick exits and to allow occupants to during daylight hours, saving emergency move about the space during a power generator power for other crucial operating outage is vital in a fire station. tasks. A space that is well day lit will aid the In an emergency situation when power is firefighters in their effort to rapidly respond unavailable, daylight can provide a safe to emergency situations.
city green building 3 Lighting Strategies by Space and Function
Functional Areas
Apparatus Bay
Lighting Design Criteria: Very Important Important Somewhat Important diffuse daylight wide distribution with occupancy controls overlapping sources
This fire station in Houten, uniform horizontal illumination high color temperature integral emergency Netherlands was designed by (4100 kelvin for electric lighting Samyn and Partners practice. lighting) The glazing on the south side encloses the apparatus bay. It is diffused light sources hierarchy of surfaces: rigs, also integrated with a photovoltaic walls, floors, ceilings panel system to provide the station energy efficient sources low maintenance with additional power and allow some of its functions to remain daylight controls Photo-controlled dimming operational in case of emergencies. or step switching
fruit" when daylighting a fire station. As a high-bay space (with a ceiling height above 15'-0"), the potential for top-lighting is significant. A well designed top-lighting system will take advantage of the dome of the overcast sky while maintaining complete direct sun control. During overcast times, the zenith of the sky dome (directly overhead) is 3 times brighter then the horizon. This means that on the darkest overcast day, horizontal skylights will deliver three times as much light as vertical Crosspointe Fire Station. Daylighting Image courtesy of Samaha Associates glazing. Translucent or light diffusing drove the design of the buildings’ glazing material will be critical to ensure site orientation and envelope. The With careful planning, daylight can be diffuse daylight during both overcast and building is oriented so that light the primary source of illumination at the clear sky days. In an overcast sky climate like monitors face south. Apparatus bays apparatus bay. An appropriate target Seattle, a good rule of thumb is to provide are stepped to best fit the site and daylight factor (DF- see definitions) for the to extend the length of the southern translucent and/or prismatic skylights apparatus bay is a daylight factor of 3. Any façade. Monitors are designed with (visible light transmission of 50% (tvis = areas below a daylight factor of 2 cannot overhangs to block direct high 0.50) or greater) at about 5-7% of the floor summer sun angles and allow low be considered day lit, and areas above a area. Light colored interior surface finishes, winter sun angles directly when solar daylight factor of 6 would likely benefit especially in the upper third of the interior gain is desired. Summer daylighting is from a reduction in glazing area. It is crucial volume, can significantly increase daylight captured by light reflecting off of the to eliminate all direct sun penetration at performance by increasing daylight inter- adjacent flat roofs and the ceiling of visual task areas within the apparatus bay. reflections within the interior space and the interior spaces to eliminate solar gain. The Apparatus bay is the "low hanging enhancing the perception of brightness.
4 city green building The apparatus bay, if illuminated from The electric lighting should be positioned above with translucent horizontal unit to light in-between the rigs to provide a skylights, can be oriented in almost any uniform light using High-bay lighting for direction due to that direct sun will be general light and fluorescent task lights controlled via light diffusing skylight at workbenches. High mounting heights glazing. Translucent or prismatic skylights raises the luminaires out of the normal will provide the most even distribution of field of view. Using the IESNA Handbook daylight across a space with the smallest under "Factors of Industrial Lighting" as amount of glazing area. Daylighting options a guide, the Apparatus bay should have such as roof monitors, clerestories, and a minimum of 50fc average on the floor "saw-tooth" monitors can also be very for general illumination from electric light successful, but are optically complex and only. Supplimental task lighting may be as Image courtesy Samaha Associates. require sophisticated design and simulation high as 100fc for workbenches and should Crosspointe Fire Station, Fairfax County, Virginia. The driving concept to ensure effective daylight performance be locally controlled. Emergency lighting of daylighting was coupled with and visual comfort. should be integral to the general lighting passive solar heating, mechanical It is critical to determine locations of critical fixtures. controls, and reflective surfaces to tasks and interior objects, such as the fire Lighting controls strategies that are most reduce electric and cooling costs. trucks when locating daylight apertures. It effective in spaces identified as industrial is also important to illuminate the vertical service include: daylight sensors to reduce surfaces of the interior- this will increase the electric lighting when useful daylight is perception of brightness in the space and available, and wall or ceiling mounted contribute to reducing contrast within the occupancy sensors. primary visual field.
Offices/Reception Area
Lighting Design Criteria: Very Important Important Somewhat Important diffuse daylight and views occupancy controls integral emergency lighting no direct glare diffused light sources energy efficient sources daylight controls local task light control hierarchy of lit surfaces: low maintenance desks, ceilings, walls, floors Daylit Office: A combination of high color rendering (CRI) Photo-controlled translucent skylights and perimeter continuous dimming windows allow this office to be illuminated with daylight alone during much of the time that it is occupied. Note that the electric Daylight should provide the first "layer" cannot be considered day lit. Areas above lights have been dimmed and shut of light in any office environment. An a daylight factor of 5 would likely benefit off via photo-sensors. appropriate target daylight factor (DF) for from a reduction in glazing area. It is crucial an office environment is a daylight factor of to eliminate all direct sun penetration all 2-4. Any areas below a daylight factor of 2 visual task areas and fixed workstations.
city green building 5 Simulation is the key to ensuring successful daylight performance. Here is a successful comparison of an actual space to a model in the Integrated Design Lab’s overcast sky simulator. The photo on the left shows the space as it was built. The photo of the model on the right shows simulated daylight distribution and approximate intensity on September 21st at noon.
Providing a carefully designed exterior shading and well thought-out user friendly blind system is critical for office daylighting. This requires orienting the spaces so they respond to the path of the sun and providing sufficient diffuse sky illumination. Achieving this requires simulation of daylight performance. In side-lit offices a good rule of thumb is that the sectional depth of the office should not exceed twice the head height of the window. This will ensure that the entire office area is within the daylight zone. Office areas are ideally oriented either north or south where direct sun can be controlled to avoid direct sun penetration and maximize daylight performance. This will require careful design of the window aperture to deliver adequate daylight while blocking direct sun and providing comfortable views. The first step is to optimize the window into its two component functions: daylight and view window (see diagrams). One way this is achieved is by using an exterior shading device and an interior light shelf. The daylight glazing occupies the upper portion of the window to maximize daylight distribution into the space (approximately two times the head height of the window). Adding an interior light shelf may increase the amount of light along the ceiling- and help to control direct sun at this aperture. Using high reflectance material on the ceiling will increase the visual comfort of the space by brightening the upper portion of the room. The exterior overhang should be designed to protect the view portion of the window from direct sun (complete shading from March 21st through September 21st), while providing a visual connection to the outdoors.
6 city green building Fixed architectural shading devices (both interior and exterior) on the south side of a building should provide roughly a 45 degree cut off angle (1:1 ratio). Fixed shading must be supplemented with interior blinds and/or fabric roll-down shades (see diagrams). This will allow occupants to control glare during periods of low-angle sun. Other options include automated exterior or interior Venetian blinds, fabric awnings, and daylight optimized blind systems. Electric lighting should provide general ambient light as well as task illumination, typically 30fc to 50fc average with electric lighting only while using only 0.79 w/sf. A direct/indirect lighting system allows for direct task lighting while providing light in the space for comfort and well being. Lighting that addresses the visual comfort or visual ergonomics of the occupants can help relief eye strain and visual stress within a facility. Accent lights also help add visual interest to the space. This could be in the lighting of a wall of pictures of past Fire Chiefs, or the accent lighting of an old battered Fire hat of deep reverence. Lighting controls strategies that are most effective in small office spaces include: occupancy sensors, personal controls through dimming, and daylight sensors to reduce electric lighting when useful daylight is available.
Active Storage What is required here is basic functional efficient overhead lighting, being mindful that some of the equipment may be UV sensitive and require special shielding. Controls should be a manual switch on and a "vacancy sensor" turning lights off when activity is no longer present.
city green building 7 Living Areas
Lighting Design Criteria: Very Important Important Somewhat Important uniform task light ambient illumination 10fc to decorative elements 20fc avg. (sparkle) horizontal illumination at task ambient and task lighting surfaces -50fc to 100fc strategies warm color temperature energy efficient sources high color rendering (CRI) no direct glare
Living/Cooking/Beanery (Kitchen and Dining Area)
The living/cooking areas are less gain during times when thermal comfort demanding from a daylighting perspective. requires cooling. Because visual tasks tend to be less Electric lighting is more critical on task areas complex at these locations, the designer such as dining tables and counter tops. has more flexibility with the amount and General lighting should make the space character of daylight employed. However, feel more residential than institutional. An it is always crucial to provide an easy to use effective way to provide ambient lighting is and effective interior glare control system to light vertical surfaces such as cabinets or such as blinds, curtains, or roll-down fabric walls. Manual controls, including dimming shades. Care should be taken to provide Images courtesy of Samaha Associates. would be appropriate here. comfortable views and control of solar heat Crosspointe Fire Station Office, Lavatory and Beanery. Living areas are flooded with daylight through Bunk Area (Private Sleeping Rooms) the monitor, low walls and interior clerestory glazing. Reading lamps and/or desk lamps along occupant. This would involve reducing the with a simple general light (using manual unwanted stray light entering the room by switches) would work best for these using shades, and if necessary, only using private bunk areas. Studies have shown amber colored light sources for safety/step that creating a quality darkness is critical lights. Local dimmer controls or manual for people to sleep and achieve a healthy on/off switches would be recommended for rejuvenation as well as to support re- private sleeping quarters. synching the circadian rhythms of the
Bathrooms and Showers
During the day, daylight should be the to support a clean, maintainable space. primary source supplemented with electric Controls should be an "occupancy sensor" lighting at task areas such as sinks and with a manual on switch to turn lights on vanities; however, at night, the general upon entering and off when activity is no lighting should be functional in order longer present.
8 city green building Dayroom (Multi-Purpose Space)
This room is a misnomer in that its primarily be used solely for views to the exterior. use is to escape from the day into a multi- Electric lighting can be more focused on functional den with flat screen TV's, video task surfaces, dramatically lit wall art and games, pool tables and other distractions localized floor and table lamps. Controls from the stresses of work. Thus this space should be manual and include zoning and is usually dark and is considered a cave dimming functions. of refuge. Windows in this area would
Workout Room
When possible, daylight should be the clean, maintainable space. Controls should primary source supplemented with electric be an "occupancy sensor" wth a manual on lighting at task areas such as sinks and switch to turn lights on upon entering and vanities; however, at night the general off when activity is no longer present. lighting should be functional to support a
Work Bench Room
What is required here is basic functional "occupancy sensor" with a manual on efficient overhead lighting and task lighting switch to turn lights on upon entering and at work benches. Controls should be an off when activity is no longer present.
Site Lighting Fire stations must blend in with the n Light only when needed using carefully- surrounding neighborhoods and yet evaluated functional, safety and comfort be a presence representing safety and criteria: permanence. Exterior lighting is an n Specify photocell and photocell/time important visual presence for the fire clock controls so lighting will be on only station, providing safety and security for the when needed. occupants. Listed below are several steps n Use self-setting or astronomic time to consider in designing exterior lighting clocks to ensure proper operation in the that meet sustainable guidelines: event of power failures. n Light only where it is needed using n Consider occupancy-sensing controls carefully evaluated functional, safety and for incandescent or fluorescent systems, comfort criteria. especially on security lighting. n Ask the question: what needs to be n Do not over-light. lighted? Justify your answers. If you cannot justify lighting an area, you probably don't need to light it.
city green building 9 Consider using IESNA criteria as maximums, luminaires not minimums. Note that improving When you must use "period" or decorative lighting quality (such as reducing glare or fixtures that emit light above horizontal, improving uniformity of illumination) may use fixtures with optical systems that have be a better solution than adding more light. very little uplight; two percent maximum Wherever possible, eliminate light from of total fixture output above horizontal is a luminaires that is projected above the good target limit. horizontal plane toward the horizon. Use Minimize the use of broad-beam floodlights techniques such as: for area lighting. Specify shields, especially n Aiming/mounting limits visor type shields for floodlights. n Full cut-off (fully shielded) "flat bottom"
Eliminate and control glare
Do not specify luminaires with unshielded rather than outward from the mounting lamps. Using the ASHRAE 90.1-2004 Exterior location. Check lamp lumen maintenance Lighting requirements, match lamp power data to avoid over lighting. with the lighting requirements. Better Match lamp wattage with mounting height. quality exterior lighting results from lower One of the most common mistakes in glare and better uniformity, when lower outdoor lighting is to install too many watts wattage lamps are used and mounted so on too short of a pole. that most of the light is aimed downward
Control Light Trespass
Locate poles and luminaires so light stays Base design decisions on IESNA within property lines as much as possible. Recommended Practices and other current Shield light sources and luminaires so criteria, conform to the appropriate that sources are not visible from off of the Lighting Environmental Zones (LZ) as property. classified by the IESNA and the International Commission on Illumination (CIE) (see Model illumination levels at property table below). As of the date of this guide, lines. Calculate both horizontal and California is the first state to adopt the vertical illumination values since both zone concept defining zones based upon may be needed to meet design or legal population density. (CA Reference) (Table requirements. of Zone).
10 city green building Lighting Energy Performance
Daylighting can have a significant impact most interior spaces (such as the offices on the energy use of a building. With proper and the apparatus bay) is photo-controlled design and the integration of electric continuous dimming. This strategy can lighting, a well day lit building can "harvest" provide substantial lighting power savings, up to a 60% reduction in lighting power with the least obtrusive adjustment of use during daylight hours. This means electric light in response to daylight. In that by using the light from the sky and some cases, such as transitional spaces, reducing electric light output during the multi-level switching may be appropriate, day, daylighting can produce significant however, sudden adjustments in light levels savings both in dollars and consumption can be perceived as obtrusive or worse by of resources. The most successful some occupants. integrated lighting control strategy for
Cost Benefits of Daylighting
The following tables show potential lighting expected from the overcast sky in Seattle power savings using photo responsive which dictates the percentage of energy lighting controls. The first table shows saved. This is then translated into a savings the input factors dictated by the design; per year in the final table. a daylight factor of 3 is optimal for spaces These savings do not include the benefits such as the apparatus bay. The next table of load reduction at other building systems shows the predicted energy savings over including reduced cooling loads, higher the year based on turning lights off during performance building envelope, or passive daylight hours. Next is the amount of light solar heating.
city green building 11 12 city green building Interior Lighting Energy Goals
Once the lighting needs of the fire station efficiency of a lighting design system, but have been established, we are then able to the true test is in its annual usage measured establish lighting efficiency goals. Below in Kwh. By trading the lighting energy is a chart based on ASHRAE 90.1 2004. in some areas with others, a sustainable A whole building approach considers design should be able to exceed ASHRAE the total building energy use through 90.1 2004 LPD by about 30% through a modeling. Connected load or Lighting combination of effective daylighting design Power Density (LPD) is one measure of the and electric lighting controls.
Space Type 2004 LPD 30% less Corridor/Transition 0.46 0.32 Electrical/Mechanical 1.45 1.02 Beanery/Kitchen Area 1.24 0.87 Restrooms 0.86 0.60 Lobby 1.32 0.92 Dayroom/Multi-Purpose 1.25 0.88 Meeting Room/Multi Purpose 1.25 0.88 Office/Administration Room 1.13 0.79 Workroom 1.91 1.34 Active Storage 0.76 0.53 Apparatus Bay 0.75 0.53 Laundry 0.60 0.42 Exercise Room 0.91 0.64 Total Building LPD 1.07 0.75
Exterior Lighting Energy Goals
Based on ASHRAE 90.1-2004, Table 9.4.5 Lighting Power Densities for Building Exteriors
Tradable Surfaces Uncovered Parking Areas--Parking Lots and drives 0.15 W/ft_ Building Grounds--Walkways less than 10 feet wide 1.0 W/linear foot Building Grounds--Stairway 1.0 W/ft_ Building Entrances and Exits--Main entries 30 W/linear foot of door width Building Entrances and Exits--Other doors 20 W/linear foot of door width Canopies and Overhangs--free standing and attached 1.25 W/ft_ Lighting power densities for uncovered parking areas, building grounds, building entrances and exits, canopies and overhangs and outdoor sales areas may be traded.
city green building 13 Non-Tradable Surfaces Building Facades 0.2 W/ft_ for each illumiated wall or surface or 5.0 W/linear foot for each illuminated wall or surface length Entrances and gatehouse inspection 1.25 W/ft_ of uncovered area (covered areas stations at guarded facilities are included in the "Canopies and Overhangs" section of "Tradable Surfaces") Loading areas for law enforcement, fire, 0.5 W/ft_ of uncovered area (covered areas ambulance and other emergency service are included in the "Canopies and Overhangs" vehicles section of "Tradable Surfaces") Lighting power density calculations for these applications can be used only for the specific application and cannot be traded between surfaces or with other exterior lighting. These allowances are in addition to any allowance otherwise permitted in the "tradable Surfaces" section of this table.
Appendix
Glazing Selection Chart LEED Sustainable Site – Credit 8: Light Pollution Reduction. It is crucial to specify the right glazing for any daylight apertures. This includes The intent of this credit is to minimize selecting glazing with appropriate visible light trespass and light pollution from light transmission (Tvis or VLT), solar the building and site. To achieve this heat gain coefficient (SHGC) and thermal credit special attention must be paid the conductance (U-Value). Spectrally selective following: glazing can provide high visible light n glare reduction transmission with a low solar heat gain n energy reduction coefficient. Glazing of this type will have a light to solar heat gain (LSG) coefficient of 2 n reduced fixture mounting heights or greater. Additionally, because of the need n precise fixture aiming to protect the equipment in the apparatus LEED 2.2 offers two credits explicitly bay, it may be critical to select glazing or dealing with daylight performance in the skylights that provide UV filtering. There Indoor Environmental Quality (IEQ) section are manufactures that make skylights that of the rating system. The first is Credit block over 98% of UV radiation. 8.1 (daylight) which requires 75% of all regularly occupied spaces to be day lit. The LEED second, Credit 8.2 (views), requires a direct Sustainable lighting design strategies line of sight to vision glazing to the exterior and specifications can play an important from 90% of regularly occupied spaces. supporting role for projects seeking LEED A properly designed daylighting system will certification. Several points in the LEED accrue other LEED credits as well. These will system pertain directly to lighting design, include Energy and Atmosphere (EA) Credit including goals for minimizing outdoor 3 (Enhanced Commissioning- to ensure that light pollution, reducing energy use, and the electric lighting controls for daylight are optimizing daylighting. properly installed and calibrated), EA Credit
14 city green building 6.1 (Controllability of Systems- Lighting), efficient dimming ballasts, and daylight higher levels of energy performance control systems can provide even more (through reduced electric lighting use, savings. better thermal performance due to exterior Under the category of indoor shading, and climate responsive building environmental quality, LEED provides massing). Additionally, exceptionally day credits for daylighting and views. lit spaces (95% or greater) may qualify for Good daylighting is a result of careful Innovation and Design (ID) Credits. architectural design to optimize diffuse Energy performance offers the most credits daylight while shielding glare and of any LEED category. Since lighting maintaining thermal control. High accounts for about 40% of the electric performance insulated windows, effective energy use of a typical commercial facility, shading and window treatments, daylight- energy-effective lighting can contribute oriented interior designs, and highly directly to LEED certification. Facility reflective finishes can add up to well- Managers are well aware of the energy lighted facilities that need minimal electric benefits of using high-efficiency fluorescent lighting during the day. Neutral tinted, and compact fluorescent lamps, LED, low-emissivity windows provide both electronic ballasts, and occupancy sensors. natural-colored lighting transmission and A lighting design strategy that integrates solar heat rejection. Combined with the daylighting to minimize the dependence on bonus of views to the outside, daylighting electric lighting can produce tremendous helps create more desirable and productive savings over typically uniform lighting facilities. See the daylighting section layouts. New technologies such as High- of this guide for specific information Efficiency T8, T5 and T5HO fluorescents on daylighting design and material lamps, ceramic metal halide lamps, LED, specification for fire stations.
Resources:
Lighting Design Lab- DOE: Energy Plus Simulation Software- www.lightingdesignlab.com http://www.energyplus.gov Integrated Design Lab- DOE: High Performance Buildings- www.integrateddesignlab.org http://www.eere.energy.gov/buildings/ The U.S. Department of Energy (DOE)- highperformance http://www.doe.gov NBI Advanced Buildings- DOE Energy Efficiency and Renewable http://www.advancedbuildings.net Energy- http://www.eere.energy.gov CALARCH Benchmark 2.1- DOE: Building Energy Software Tools http://poet.lbl.gov/cal-arch/ directory- Windows for High Performance Buildings- http://www.energytoolsdirectory.gov http://www.commercialwindows.umn.edu
city green building 15 Books:
Advanced Energy Design Guide - Small Office Daylight Design of Buildings IESNA Lighting Handbook, 9th Edition A large majority of this guide was based Sun Wind and Light upon material from the IES Sustainable Lighting Design and Application Guide. Daylighting in Sustainable Design
Definitions
Daylight Simulations Horizon Computer simulations can be another The circular line bounding an observer's effective way to test daylight performance. view of the surface of the earth where the These can be used for spaces that are sky and earth seem to meet. difficult to model and also as an additional level of understanding for space tested Glare on the heliodon and in the overcast sky Excessive contrast or light intensity that simulation. Computer simulation tools creates discomfort. An example might be range from sophisticated programs such as the reflection of the direct sun off specular Radiance, which provides photo realistic surfaces in the interior of a space. This is renderings and illumination data, to simple most troublesome when the disc of the sun SketchUp shadow simulations. is visible to the human eye.
Heliodon Skylight A device for adjusting the angle between Horizontal glazing set in the roof of a a flat surface and a beam of light to match building. the angle between a horizontal plane at a specific latitude and the solar beam at a Monitor specific time. High vertical glazing usually projecting Overcast Sky Box above the roof of a building.
Simulates a typical overcast day in order to Daylight Window measure effective daylight during overcast conditions. Using photo sensors and Vertical glazing used for bringing daylight photography both a quantitative and a into a space. Usually the top third of qualitative analysis can be achieved. window utilizing a light shelf to carry daylight farther into the space and reflected Overcast Sky Dome light onto the ceiling.
Overcast conditions create a dome of light View Window where the illumination directly overhead is 3 times as bright at the zenith then at the Window used primary to see from the horizon. interior to the exterior. Not the primary source of daylight.
16 city green building Light Shelf Daylight Factor Interior shading device used in conjunction The percentage of available daylight that with a daylight window to cast a reflection reaches a room. A daylight factor of 2 is the onto the ceiling and project light farther minimum for a space to be considered day into a space. lit.
Exterior Shade Circadian Rhythms Shade mounted on the exterior of a The human body's response to the building to cast a shadow on the window earths night and day cycle, especially and prevent direct sun light from reaching as it concerns the body's production or the glazing. suppression of the hormone melatonin.
Contacts City Green Building (206) 684-8880 www.seattle.gov/dpd/ greenbuilding Prepared By: Lighting Design Lab http://www.lightingdesignlab.com
Printed on recycled paper.
city green building 17