19 minute read
LIGHTING & ELECTRICAL
by IdeaSoil
example of where positive auditory distractions are often necessary. An audio system and associated infrastructure for music players, in addition to internet access may be required. Smart terminals, wireless headsets, and remote controls should be provided to patients during painful procedures to drown out unpleasant sounds and distract them from the discomfort and length of the procedure.
Key conditions that could increase the score: • Patient experience will be painful or uncomfortable; fear, worry, or boredom is likely. • Procedure or activity will last multiple hours. • Conditions permit user control of content and volume. It is unlikely that anyone else will feel forced to listen.
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COLLECTIVE GOAL CONSIDERATION After scoring a room or space on the six main acoustic goals, review the results collectively as the layout, size, shape, and appearance of the room begin to take form. Consider, as an example, a nurse station and connecting corridors in a specialty-orthopedic surgery center. Nurse stations are active places that can get quite noisy. A lot of private information is exchanged between patients, family members, nonclinical caregivers, and nurses.
The high-priority acoustic goals are noise control, accurate communication, and auditory privacy. Designed background sounds are important in relation to achieving auditory privacy. It is the wrong place for positive auditory distractions since nurses need to focus on their duties.
Nurses Station and Corridors
Accurate communication Low Moderate High
1 2 3 4 5
Auditory privacy Low Moderate High
1 2 3 4 5
Noise control Low Moderate High
1 2 3 4 5
Designed background sounds Low Moderate High
1 2 3 4 5
Positive auditory distractions Low Moderate High
1 2 3 4 5
The primary design strategy when accurate communication, noise control, and auditory privacy are all needed in open or semi-open spaces, such as a nurse station, is to implement high-performing, sound-absorbing finishes. While carpet tiles on the floors have proven to be part of an overall, effective solution, the easiest way to add sound absorption is by using an acoustic ceiling with a high NRC rating of 0.90 or more. It absorbs troublesome sound reflections and reverberation, making it much easier to communicate. The same high-performing acoustic ceiling provides noise control as sound waves travel down the corridors toward patient rooms. Fewer patients are disturbed. When those waves are speech or other sounds that are meant to be kept private, the ceiling attenuates them so fewer people hear them.
Using electronic sound masking as designed background sound inside procedure and exam rooms to mask any noise not absorbed by the acoustic ceiling is the next most important design strategy. Using high-NRC ceiling panels, carpet tiles, and sound masking, especially in a low-acuity orthopedic surgical center where it is more likely that the patient room doors can be closed at night, is an effective design strategy that considers all of the prioritized acoustic goals.
DESIGN STRATEGIES As one progresses through the design of various room types in a healthcare facility, the following design recommendations should be given priority consideration. Note that some recommendations prove effective for achieving multiple acoustic goals.
Accurate communication:
• Use sound-absorbing surfaces such as an acoustic-panel ceiling with the optimal NRC rating (0.70 good, 0.80 better, 0.90 best) and carpet tiles to decrease reverberation. Under the most critical conditions, wall absorption may also be required. • Lower the ceiling to decrease the room volume and reverberation. This also typically moves the sound absorption closer to sources of interfering noise. • Use an audio system to amplify speech (limited application in healthcare settings). • Ensure that noise from equipment is attenuated adequately by locating it remotely or enclosing it in soundisolating construction.
Auditory privacy:
• Provide private enclosed rooms with full-height walls that extend from floor slab to floor slab. Use partition constructions with optimal STC ratings. • Use swinging doors that are solid-core wood or insulated metal and acoustic seals around the perimeters. • When enclosed rooms are not possible and privacy is needed, use sound-absorbing surfaces such as an acoustic-panel ceiling with an NRC rating of 0.90, combined with designed background sounds to provide masking.
Noise control:
• Create acoustic zones. Keep noisy functions remote from quiet functions. Use “buffer zones” such as stairways and storage rooms between noisy and quiet zones. • Provide sound-rated partitions and doors between noisy functions and quiet functions. • Use sound-absorbing surfaces such as an acoustic-panel ceiling with a high NRC rating of 0.90 or higher to limit the amount of noise that transmits between acoustic zones.
Designed background sounds:
• Consider the purpose of the background sounds. • Electronic sound masking provides speech privacy. • Music is uplifting and energizes. • Nature sounds are comforting and soothing for relaxation and stress relief.
Positive auditory distractions:
• Consider whether they should be more communal or individual. • Consider whether they are physical or electronic. • Provide user control whenever possible. • Provide infrastructure such as a stage platform and nearby changing/storage rooms or, if electronic, appropriate playback or broadcast devices, internet access, wireless devices, and secure storage and charging locations.
The ways and locations in which healthcare is being provided are changing rapidly. Healthcare is moving away from acute-care hospitals and toward more local and convenient ambulatory services. To bridge the gap, first understand what the patient and caregiver will experience inside the space. Then assess and prioritize the six core acoustic goals. Then select the design strategies that work well for the project, based on the prioritized acoustic goals. Using this design approach will lead to optimal acoustic conditions in future, high-performing healthcare facilities. CA
Gary Madaras, PhD, Assoc. AIA, is an acoustics specialist at Rockfon, Chicago, where he helps designers and specifiers learn the Optimized Acoustics design approach. Madaras is a member of the Acoustical Society of America (ASA), the Canadian Acoustical Association (CAA), and the Institute of Noise Control Engineering (INCE). He can be reached at gary.madaras@ rockfon.com.
PODCAST: ACOUSTICS, HEARING LOSS, AND ESL Two other factors that are affected by acoustics are hearing loss and individuals who use English as a second language. The role these two factors play are the subject of a podcast editorial director Gary L. Parr recorded with Gary Madaras, author of this article and acoustics specialist at Rockfon, Chicago. Listen to the podcast at commercialarchitecturamagazine.com/1901facousticpod.
Trends Shape Lighting Design
Tips for integrating natural light with artificial light.
Omar Rivera, LEDVANCE
A space’s visual appearance is heavily dependent on how it is lighted. Intensity, direction, uniformity, and spectral distribution determine light quality. Natural light presents a highly variable but potentially very high-quality light source to the mix. Special care should be taken to ensure the natural light and electric lighting work together to best serve a space’s task and aesthetic needs. C ontemporary lighting design is being shaped by four major trends: energy codes, daylighting, using LEDs as a primary electric-light source, and connecting LED lamps and luminaires to responsive controls.
These concepts should not be considered independently, but rather combined, to provide a holistic illumination solution. Natural and artificial light, in concert with lighting control, form an integrated illumination system. Following are tips for achieving a system in lighting design that produces good vision and good visual comfort and rendering.
DAYLIGHTING
Natural light is a highly desirable free and abundant illumination source. Leveraging this resource, daylighting, in sustainable design provides a connection to nature, excellent color rendering, sensory variability, good modeling, and indirect light on walls and ceilings, resulting in a pleasant and comfortable space. Numerous studies, conducted over the years, attest to its value for human beings in the built environment.
Avoid direct sunlight. Good daylighting design harnesses sunlight and delivers it to an interior space as a general light source. That’s not the hard part. The difficult part is controlling the light to avoid visual glare and thermal gain. Direct sunlight should be avoided except in circulation spaces.
Control daylight. For illumination, the design goal should be to maximize the uniform distribution of diffuse daylight. Light coming into a building can be controlled using glazing, shades, blinds, louvers, or other media. Generally, all sides of a building should be shaded except for the north side.
Light-control media can be automated or tied together to provide
This is a suitable application for daylight harvesting to save energy and comply with energy codes. General lighting could be zoned as two separate parallel rows of downlights (and possibly a third, depending on natural-light penetration). Each control zone could be switched, although with the seating, it may make more sense to step-dim for user comfort. In this case, high levels of bright natural light and glare during certain parts of the day can be mitigated with wireless window treatments, which are also highly recommended in work areas that contain computers screens.
remote user control and overall convenience.
Maximize daylighting distribution. Natural light can enter a building through sidelighting or toplighting, the design of which allows architects to control its quantity and quality. Generally, natural light should enter a space from as high a vantage point as possible and cover areas where users need it. To maximize usable daylighting area, perimeter zones can be increased. Features such as light shelves can push the light deeper into a space while also diffusing it. Automatic devices, including heliostats, can maximize usable daylight.
ARTIFICIAL LIGHT Artificial electrical lighting may be considered as three functional layers: task, ambient, and accent lighting. Natural light generally provides ambient lighting and is integrated with that layer. The design goal is to provide quality illumination that has a seamless look and feel— in other words, ensuring a space that looks great with natural light and without. The way to accomplish this is to establish clear illumination goals for each space and to merge natural light with artificial electric light into a cohesive design, resulting in a high-performance and integrated system.
Electric light should match natural-light patterns.
Natural light may not uniformly cover an entire space. Instead delivers gradients of intensity reaching into the space. General lighting should be placed parallel to the natural light, allowing luminaires to turn off or dim when sufficient natural light is available. Otherwise, the electric lighting should place light on the same surfaces as the natural light. If the natural light is distributed on walls and ceilings (as is often desirable), the electric lighting should do the same. Note that some variation in light levels over the course of the day may be acceptable and even preferred, but surface brightness should remain relatively consistent. Use light-colored surfaces, with brighter surfaces kept out of the line of direct sunlight.
Match the color quality. Specify the light source with a neutral- or cool-white correlated color temperature (CCT, typically 3500 K to 4100+ K). Otherwise, if a warm-white CCT ( <3500 K) is specified, the light emission, when mixed with very cool daylight ( >5000 K), may make the light sources appear yellow.
Consider supplemental lighting. Be aware of contrast between areas and surfaces receiving natural light and those that will not. In deep spaces, consider wall washing or accent lighting on rear walls. In spaces where natural light provides insufficient light on ceilings, such as spaces with skylights, consider luminaires with some uplight distribution.
CONTROLS Automatic lighting controls are a staple in new construction and renovations because of commercialbuilding energy codes, and they typically require daylighting-responsive control. This control strategy reduc-
es lighting through switching or dimming to maintain a target light level, saving energy. Switching is typically ideal for circulation spaces, while dimming is excellent for spaces that are regularly occupied by users performing intensive visual tasks. The introduction of automatic lighting controls creates an opportunity to realize value far beyond basic energy savings.
Dimming is standard. With fl uorescent luminaires, dimming could be costly, while with LEDs, it is fairly standard. Dimming is ideal for automatically reducing lighting while a space is occupied. Good performance requires selection of a quality driver in the LED luminaire. It should be confi rmed that the driver and all control devices are interoperable.
Consider luminaire-level lighting controls. Energy codes stipulate daylighting areas, control zoning (lights assigned to controls for daylight response), and minimum load-reduction capability. A simple way to address this and other code requirements is through luminaire-level controls, which integrate occupancy and light sensors into luminaires for highly responsive control and maximum energy cost savings.
Connected lighting offers big value. Advances in wireless communication and microprocessing have produced a second revolution in lighting: intelligent control. Connected lighting offers intelligence, sensors, and two-way data communication, and as such could be considered Internet of Things (IoT) ready, though the devil is in the details as to how accurate that is for a given product. In any case, the result is maximum energy cost savings, ready energy-code compliance, and the ability to produce data viewable in control-system software or shared with third-party software. This information, in turn, can be used for purposes such as space optimization, producing greater value.
Control color. Another big opportunity with LED lighting is its ability to change the spectral content in the light emission. In other words, with certain products, we can change the color or shade of white light. This allows the light in a space to gradually change to match the quality of the natural light and simulate the daylighting cycle in spaces not receiving natural light. Spectrum, along with dimming, can be used in circadian lighting strategies, a nascent trend in the industry.
GETTING IT RIGHT Good daylighting and natural light/electric light integration can benefi t from commitment throughout a project, good planning, modeling and mockups, and commissioning, to make sure the fi nal installed project satisfi es project requirements. For daylighting and daylight response, energy codes provide a suitable baseline from which additional opportunity can be derived by understanding how occupants will use a space. Architects should continually educate themselves on new technology and opportunities with LED lighting and lighting controls. Specifi ers should seek out manufacturers and channel partners with the appropriate experience, expertise, and reputation. By understanding the application and properly integrating natural light and artifi cial electric light, architects can deliver illumination that satisfi es clients with its functionality, comfort, fl exibility, energy effi ciency, and added value. CA
Omar Rivera is head of luminaires in the United States and Canada for LEDVANCE, Wilmington, MA, maker of Sylvania general lighting.
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EDITORS’ CHOICE
Contemporary interior LED pendant
Verner pendant:
Contemporary LED luminaire No visible hardware High-ceiling applications
The Verner pendant is a deco-performance fixture that combines high light output with a geometric aesthetic to enhance interior spaces while providing useable light. With no visible hardware, the pendant can be used in high ceiling applications, open areas, or spaces where diminished focus on the ceiling is the aim. The luminaire’s contemporary look is completed with a classic spherical diffuser. The cone-like shade ensures that light is directed downwards and is suited to applications where designers want to avoid indirect light illuminating the ceiling. For applications where a high output of downlight is required as much as a decorative element, the LED light source delivers 2,400 lumens in the standard version and more than 4,200 lumens in a high-output version. Available in 3000 K, 3500 K, or 4000 K, the pendant can be cable or stem mounted. The standard exterior finish is black or white as standard, while the shade interior is white for optimal light reflection.
Eureka, Montreal Circle 50 eurekalighting.com
Linear luminaires Seem 4 recessed grid and Seem 4 direct/indirect linear luminaires are 4-in. aperture lights for diverse spaces and provide a coordinated appearance. The recessed grid has been simplified in joining and alignment, and field-adjustable mounting brackets speed installation. Above-ceilingdriver access allows serviceability. The direct/indirect version is re-designed to coordinate with the existing direct luminaire with smaller housing height, matching suspension points, and 1 1/2-in. popdown lens. Available in suspended and wall-mount options in multiple finishes, the luminaires are available in 1-ft. increments.
Focal Point, Chicago Circle 52 focalpointlights.com
Wall-wash/indirect LED Dipper LED is a wall-wash/indirect lighting luminaire that can be mounted on a track or as a wall/ceiling canopy.
Models are 8 or 12 in. in width in black, white, or silver finish. Track mounts have double-locking adaptors to hold the fixture in place during horizontal or vertical adjustments.
Nora Lighting, Commerce, CA Circle 51 noralighting.com
Occupancy sensors with dimming Wattstopper HBP-2x2 series is a line of high-performance high-bay passive infrared (PIR) occupancy sensors with continuous dimming and daylighting harvesting for high-bay applications. The addition of the dimming functionality, which automatically adjusts electrical light levels based on ambient light contributions, helps increase energy savings and meet the latest warehouse energy code requirements, including California Title 24, ASHRAE 90.1, and IECC. The sensors provide automatic daylighting control of individual LED lighting fixtures and are available in two models, a low-voltage HBP-202 sensor and line-voltage HBP-212 sensor.
Legrand, San Jose, CA Circle 53 legrand.us
Tamper-resistant receptacles A line of heavy-duty industrial specifi cation-grade 15-A and 20-A 250-V tamper-resistant single receptacles provides a solution that meets the requirements of Article 406.12 of the National Electric Code, as well as Canadian safety requirements. Weather-resistant versions comply with the requirements of NEC Article 406.9 for damp and wet locations.
Leviton, Melville, NY Circle 56 leviton.com
Pendant, ceiling-mount luminaire Rotonda is a shallow-profi le, circular pendant that provides LED illumination for a variety of applications. Available in three diameters with open or closed shades, 30 shade colors in chintz fabric are available. The ring-shaped shades may be specifi ed with different colors on the inside and outside for added visual impact. Mounting options include surface, canopy, or stem.
Nordeon USA, Gaffney, SC Circle 54 nordeon-usa.com
LED desk lamps The Essentials collection includes LED offi ce lamps in 10 contemporary designs, including lighting with a traditional gooseneck style, models with an architecturally inspired adjustable arm, and those with a rectangular light and an oval lamp. The products have touch-activated switches with multiple brightness settings, a removable base and integrated desk clamp, a built-in USB port, and a wireless charging station compatible with Apple and Android products.
OFM, Holly Springs, NC Circle 57 ofminc.com
Power grommet slider The PCS104 power grommet slider is an in-desk power solution for power options at the surface level. Two lids act independently to access the power receptacle and/or USB input. Three fi nishes are available.
Doug Mockett & Co., Manhattan Beach, CA Circle 55 mockett.com
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