Executive Summary This report contains information about the existing lighting conditions for the CNBC Global Headquarters in Englewood Cliffs, New Jersey, including hardware, controls, power density, and performance evaluation. Design criteria applicable to the business news open office, first floor cafeteria, east lobby, and east plaza/façade are outlined through the use of the IESNA Lighting Handbook. Allowable power density and control requirements for the respective spaces are also reported as per ASHRAE Standard 90.1. The business news room, east lobby, and east plaza do not meet the recommended IESNA illuminance levels. The business news room falls slightly below at 26 fc of the 30 fc recommended value. The plaza, on the other hand, falls drastically below at 1 fc of the 5 fc recommended value. This may cause safety and security issues especially at night. Furthermore, because the canopy is the only brightly lit surface, the effects of glare can be exaggerated and cause visual discomfort. The lobby, although having low illuminance levels due to artificial light, has 3 story glass curtain walls that allow for much light during daytime conditions. The first floor cafeteria illuminance is twice of the recommended levels of 10 fc; however, daylight is taken into account near spaces adjacent to windows where illuminance levels are lower than the spaces, which see no natural light. All the interior spaces studied exceed the power density standards of ASHRAE 90.1. The business news power density at 1.5 W/ft 2 falls slightly above the recommended 1.3 W/ft 2. The cafeteria exceeds both the allowable power density for task lighting and for decorative lighting. The lobby s task power density conforms to the standard 1.8 W/ft 2 while the power density for decorative and accent lighting exceeds the standard of 1.0 W/ft 2. Power density for the plaza is very low at 0.14 W/ft 2 and reflects the lack of sufficient illuminance levels in this space. All the spaces meet the ASHRAE 90.1 control requirements with the exception of the business news room and the cafeteria which needs additional switches as per ASHRAE 90.1 control standards. All lighting calculations in the spaces discussed were done by creating a simple 3- dimensional CAD model of the space, importing it to AGI 32, and applying the appropriate material reflectance and corresponding luminaire photometry files. 1
Business News General Description The Business News space is a large open office area serving the 3 adjacent broadcasting studios. Located in the core of the building, no natural light is used in the room. Support staffs for CNBC s signature newscasts are the primary users of the space. There is a heavy use of VDT screens in this area as well as tasks needing horizontal illuminance. Curved stairs led up to the business news conference room and the CEO s office. The walls have an abstract mural composed of mainly dark blues and golden yellow tones. Dark gray carpet is used throughout the entire space. 2x2 ceiling panels grouped into lowered 20 x14 sections radiate from the south end of the space. The entire room is furnished with 4 high gray workstations with white tabletops equipped with desktop VDT screens. Moreover, large screen monitors hang on the north wall to show the live recording at the adjacent broadcasting studio. See furniture layout on plans. Dimensions: 82 x114 x26 (approx.) Existing Lighting System Lighting Fixture Schedule Type Quantity Description Lamp Voltage Ballast Watts F3 7 7 Cross Baffle Downlight, Recessed Ceiling Mounted F48 117 10 Radial Louver Downlight, Recessed Ceiling Mounted (2) 26W Compact Fluorescent - CF26DD/E830 (1) 100W ED-17 Metal Halide - MHC100/C/U/M/4K 277V 277V 58W 118W Existing Power Density: 1.5 W/sf (exceeds 1.3 W/sf as per ASHRAE Standard 90.1) There are no decorative or accent lighting in this space that can constitute an additional 1.0 W/sf. Furthermore, the luminaires used in the space are non-conforming to VDT standards, thus an additional power allowance of 0.35 W/sf cannot be taken. Existing Controls: The entire 9,348sf of space is currently controlled as one whole zone in the dimming panel, and is controlled through the building time clock via lighting relay panels. The lights are set to operate during business hours with a 3-hour override. Switches are located at each of the 4 entrances to the workspace. Although it meets the automatic shut off provision of ASHRAE Standard 90.1, it does not meet the switching requirement. As per the standard, there should be 4 switches serving a maximum of 2,500sf. 2
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Design Criteria (Per IESNA Lighting Handbook) Horizontal Illuminance The recommended light level on the work plane is 30 fc. Task Lighting can also be used to add more illuminance on the work plane, which occupants can control for themselves. The task should have the most illuminance. Vertical Illuminance The recommended vertical illuminance is 5 fc. Due to the extensive use of VDT screens, proper attention must be attended to the luminance ratio between the screen and the remote room. Vertical illuminance along the walls is also desirable to accentuate the murals and help produce a relaxing ambiance. Thus, vertical illuminance on the walls should be the second brightest. Design Scheme The lighting in the space should promote a conducive working ambiance. The lighting layout should have clean lines and reflect the modern look of the space. Therefore, the luminaries used should blend well with the architecture of the ceiling and complement the space. Direct Glare It is important to avoid direct glare for the visual comfort of the occupants. problems from direct glare can arise from artificial light only because the space is isolated in the core of the building. Reflected Glare Reflected glare from luminaires on the VDTs on the workstation should be avoided because of heavy computer use. Occupants of this space also rely on two large screens on the north end of the room to monitor the progress of the broadcast in the adjacent studios. Source/Eye/Task Geometry Heavy use of VDT screens on the individual workstations calls for proper geometries in order to reduce or eliminate reflected glare. Careful consideration of this geometry is also essential so that the two screens on the north wall can be viewed from the entire room with little glare. Light Distribution on Task Plane Uniform light distribution on the work plane is essential for the occupant s visual comfort when performing visual tasks such as reading. This is also essential in being able to achieve proper luminance ratios. Color Appearance The walls surrounding this space have very bright and colorful 4
abstract murals. Lamps with a color rendering index in the 80s and neutral color temperature should be used to illuminate both the blue and yellow colors. Neutral color temperature is necessary so that occupants feel comfortable in the space. An office space such as this shouldn t have low CCT lamps like for residential use, or a very high CCT and have the space appear cold and harsh. Light Distribution on Surfaces Even distribution on the workstation partition is important because it is part of the immediate surrounding that would need to be considered to achieve proper luminance ratios. Parts of the wall that have the large VDT screens should have lower illuminance so that the screens can be clearly seen. However, because of the fancy murals on the walls, those without the large VDT screens should be well lit as to showcase them. Luminance ratio The recommended maximum luminance for task and background is 3:1, while task to field of view is 10:1. Appearance of Space and Luminaires This space is visible from the main broadcasting studio, thus the space must appear visually pleasing for both television guests and office occupants. Even though the space is not included as a background image for broadcasting, it should still remain aesthetically pleasing and not distracting to the live newscasters that can see into the space. Shadows Care must be taken in placing the luminaires. Reading and writing tasks that occur on the desk can be shadowed if the occupant leans over and luminaires are improperly located. Facial shadows must also be avoided to give occupants a more refreshed appearance. (Per ASHRAE Standard 90.1) Power Allowance ASHRAE Standard 90.1 recommends 1.3 W/sf of power for open spaces in office buildings. Control Requirements The standard mandates an automatic control device to shut off lighting by time of day basis or through the use of occupancy sensors that shall turn off after 30 minutes of inactivity. Furthermore, each device within an enclosed space shall control only a maximum of 2,500sf for spaces less than 10,000sf. Override switch shall also be provided to override the automatic control device for no more than 4 hours. Because this is a large space with numerous occupants, general lighting controls should be 5
inaccessible. However, individuals can be given more control of their task lighting with accessible switches with which to control them. Parameters Used for Calculations Light Loss Factors Type Maintenance Category Cleaning Interval F3 IV Clean, 24 mos. F48 IV Clean, 24 mos. RCR RSDD LDD LLD BF Total LLFs 1.1 0.97 0.80 0.86 0.88 0.59 2.3 0.97 0.80 0.75 0.95 0.55 Assumed Finishes and Reflectance o Exposed Ceiling: Material: paint (Benjamin Moore: kendall charcoal) Reflectance: 11.8% o Ceiling Tiles: Material: 2x2 ceiling tiles (style: Armstrong Ultima) Reflectance: 90% o Floor: Material: dark gray carpet (reflectance from color matching) Reflectance: 20% o Walls: Material: paint (Benjamin Moore: evening blue and yellow) Reflectance: 8.0%, 67% respectively Average Reflectance: 37.5% 6
o Stairs: Material: maple hardwood (reflectance from color matching) Reflectance: 65% Existing Lighting Performance Average Horizontal Illuminance: 26 fc (on work plane) Average Vertical Illuminance: 8 fc Renderings 7
Psuedocolor: Illuminance 8
Psuedocolor: Luminance 9
Illuminance Isometrics Existing Conditions Critique The existing lighting condition space meets vertical illuminance levels, however, the horizontal illuminance falls slightly less than the required. Moreover, the space exceeds the 1.3 W/sf ASHRAE power allowance. The space is fairly uniform with a uniformity gradient of 3.19. Because of the heavy use of computers, direct and reflected glare remains and issue. The existing metal halide fixtures are not VDT proof, therefore, use of VDT approved fixtures can reduce glare on the screens. The walls where 2 large screens are located (left wall on rendering) are bright, thus reducing the visibility of the screens. Furthermore, the plan showing the furniture and the luminaire layout, reveal large gaps in the ceilings where there are no lights. A good portion of the big breaks without lights fall right over some workstations causing lighting levels in these areas to be lower. 10
First Floor Cafeteria General Description The first floor cafeteria serves as an extension of the cafeteria seating area on the ground floor for the use of the occupants of the entire building. This space is solely used for eating purposes. Ribbon windows run along the north wall for the entire length of the space looking out onto the outdoor courtyard. The walls are of typical white paint. The half-height wall that runs parallel with the white terrazzo stairs is finished with Anigure wood veneer as well as ½ thick low glass wall running along the opposing side of the stairs. The exposed ceiling is painted dark charcoal, while dropped ceiling is painted white. Ceiling over the larger seating area on the south is finished with metal ceiling tiles. The north end of the cafeteria has white terrazzo floor tiles with accents of blue tile while the south end of the cafeteria has blue, yellow, and cream terrazzo tile mixed to create patterns. Typical furnishings in this area are cafeteria tables and metal chairs as seen on the plans. Dimensions: 15 x105 x13 and 52 x79 x13 (approx.) Existing Lighting System Lighting Fixture Schedule Type Quantity Description Lamp Voltage Ballast Watts F6 14 Ceiling Mounted Recessed Pin-Hole Low Voltage Downlight (1) 50W MR- 16/FL40 120/12V 55W (Transformer) F8 244 Surface Mounted Mini Staggered Light Channel for Cove F15 56 Ceiling Surface Mounted Fluorescent Fixture F25 44 Ceiling Mounted Recessed Mounted Halogen Downlight F26 24 Ceiling Pendant Mounted Incandescent F27 26 Ceiling Surface Mounted Fluorescent Channel F32 81 Ceiling Mounted Recessed Low Voltage Adjustable Accent Light (2) 28W T5 for every 4 F28T5/830 (1) 32W-T8 for every 4 F32T8/830 (1) 60W BT-15 Halogena White (1) 60W BT-15 Halogena White (3) 13W CF for every 2 CF13DD/E/830 (1) 42W MR-16 Narrow Spot 277V 277V 277V 120V 277V 30W 35W N/A N/A 45W for 3 lamps 120/12V 48W (Transformer) 11
F33 34 Ceiling Mounted Pendant Incandescent (1) 150W BT- 15 Halogena White 120V N/A Existing Power Density: 3.27 W/sf (greatly exceeds 1.4 W/sf as per ASHRAE 90.1) There are no decorative or accent lighting in this space that can constitute an additional 1.0 W/sf. Existing Controls: The 5,683sf space is currently controlled as two zones (north and south) in the dimming panel, and is controlled through the building time clock via lighting relay panels. The lights are set to operate during business hours with a 3-hour override. Two switches for each zone are located at the 2 entrances to the cafeteria. Although adhering to the automatic shut-off in lighting, there are not enough controls in the room. According to ASHRAE Standard 90.1, 3 switches should be in place, each controlling 2,500sf or less. 12
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Design Criteria (Per IESNA Lighting Handbook) Horizontal Illuminance The recommended light level on the work plane is 10 fc. The first floor cafeteria functions as an extended seating area and there is no food service area. To create a relaxing effect, vertical surfaces and the perimeter should have higher illuminance, thus horizontal illuminance comes second. Vertical Illuminance The recommended vertical illuminance is 3 fc. However, artworks hang on some of the wall that may need more illuminance. To create a more relaxing ambiance, perimeter lighting should be considered. Accordingly, the vertical surfaces, should be the brightest in order to achieve a more relaxing effect. Thus, vertical illuminance levels in some walls can be increased up to 15 fc. Design Scheme The lighting in the space should again reflect the modern look of the building. The most of the luminaries should be integrated with the architecture and simply blend in. A sense of relaxation due to lighting should also be applied to the space to create a nice dining ambiance. The wood and the blue terrazzo walls should also be featured to create a drastic contrast with all the white materials in the space. Direct Glare It is important to avoid direct glare for the visual comfort of the occupants. In addition to the artificial light, direct glare can also come from sunlight coming in from the north and south. Reflected Glare Reflected glare from the glossy floor can affect visual comfort of occupants and should be taken into consideration. Color Appearance The lighting system should render the food well to make them appealing to those dining. Therefore, lamps with color rendering index of at least 80. A neutral color temperature is necessary so that occupants feel comfortable in the space. A public dining space such as this shouldn t have low CCT lamps like for residential use, or a very high CCT and have the space appear cold and harsh. System Control and Flexibility The cafeteria seating area is a large space that can be also be used for other functions. Controls can be used to create different scenes in the space. 14
(Per ASHRAE Standard 90.1) Power Allowance ASHRAE Standard 90.1 recommends 1.4 W/sf of power for dining areas in office buildings. Control Requirements The standard mandates an automatic control device to shut off lighting by time of day basis or through the use of occupancy sensors that shall turn off after 30 minutes of inactivity. Furthermore, each device within an enclosed space shall control only a maximum of 2,500sf for spaces less than 10,000sf. Override switch shall also be provided to override the automatic control device for no more than 4 hours. Controls for the cafeteria space should also be inaccessible to the occupants to prevent tampering with light levels. Parameters Used for Calculations Light Loss Factors Type Maintenance Category Cleaning Interval F6 IV Clean, 24 mos. F8 I Clean, 24 mos. F15 I Clean, 24 mos. F25 IV Clean, 24 mos. F26 III Clean, 24 mos. F27 I Clean, 24 mos. F32 IV Clean, 24 mos. F33 IV Clean, 24 mos. RCR RSDD LDD LLD BF Total LLFs 1.2 0.97 0.80 0.95 1 0.74 2.1 0.82 0.88 0.95 0.98 0.67 1.7 0.95 0.88 0.95 0.98 0.78 1.7 0.97 0.80 0.94 1.0 0.73 1.2 0.97 0.84 0.94 1.0 0.76 2.1 0.82 0.88 0.90 0.98 0.64 1.2 0.97 0.80 0.95 1 0.73 2.1 0.97 0.80 0.88 1.0 0.68 Assumed Finishes and Reflectance o Exposed Ceiling: Material: paint (Benjamin Moore: kendall charcoal) Reflectance: 12% 15
o Ceiling: Material: paint (Benjamin Moore: simply white) Reflectance: 92.6% o Ceiling Tiles: Material: perforated metal fabric ceiling (stainless steel) (reflectance from Armstrong ceiling product matching) Reflectance: 30% o Floor: o Walls: Material: terrazzo tiles (cream, gray storm, arctic white) (reflectance from color matching) Reflectance: 83.3%, 6.3%, 90.1% Average Reflectance: 59.9% Material: paint (Benjamin Moore: simply white) Reflectance: 92.6% o Half-Height Wall: Material: anigure wood veneer (reflectance from color matching) Reflectance: 56% o Glass Stair Railing: Material: ½ clear glass Transmission: 91% Reflectance: 8% o Windows: Material: gray tinted glass Transmittance: 43% Outdoor Visible Light Reflectance: 6% 16
o Stair: Material: terrazzo (cream) (reflectance from color matching) Reflectance: 83.3% Existing Lighting Performance Average Horizontal Illuminance: (on work plane) North end: 22.2 fc Middle: 38.4 fc South end: 18.2 fc Average Vertical Illuminance: North end: 15.8 fc Middle: 33.3 fc South end: 16.5 fc Renderings 17
Psuedocolor: Illuminance Psuedocolor: Luminance 18
Psuedocolor: Illuminance 19
Psuedocolor: Luminance 20
Illuminance Isometrics Existing Conditions Critique Horizontal and vertical light levels throughout the cafeteria are twice the needed illuminance level prescribed by the IESNA. Similarly, the existing power density is more than twice of which ASHRAE 90.1 allows. The existing system, however, addresses the issue of additional natural light that comes in from the windows on the north and south ends of the cafeteria where artificial light levels are lower. High light levels in the space also make it appear harsh and does not appear to be a relaxing atmosphere. The space also looks very bland because of the predominantly white surfaces; therefore, use of color can take into play in the new lighting design. Fairly even lighting distribution also helps in the monotonous appearance of the space. Other than a few walls that have been washed with light, there are no dramatic contrasts in the lighting of the space. The ceiling also appears very cluttered with luminaires seemingly placed haphazardly especially in the central portion of the cafeteria seating. 21
East Lobby General Description The East Lobby serves the main entrance of the building. There are 3-story tall artwork/banners with abstract prints of blues and yellow that line the lobby wall, behind which are entrances to the Business News studio and the Auxiliary Studio. The east wall of the lobby is composed entirely of a curved tinted glazed glass curtain wall. Perforated metal fabric sheet line the ceiling, while blue terrazzo tile line the floor. Two sidewalls that run 3 stories are covered with Anigure wood veneer. Furnishings in this space are the reception desk and leather upholstered benches. Furthermore, the 3-story banners are cut out near the bottom where VDT screens have been inserted. The VDT screens play the broadcasting that is going on inside the studios and they face the glass curtain walls in the lobby. Dimensions: 24 x92 x39 (approx.) Existing Lighting System Lighting Fixture Schedule Type Quantity Description Lamp Voltage Ballast Watts F27 78 Surface Mounted Fluorescent Channel (3) 13W CF for every 2 277V 45W for 3 lamps (Mounted under lobby seating and reception desk - Decorative) CF13DD/E/830 F39 20 Floor Recessed Adjustable (1) 75W Halogen 120V N/A Accent Light (Decorative) F40 10 Semi-Recessed Ceiling Mounted Wall Washer F41 11 Ceiling Recessed Mounted Adjustable Accent Light (Decorative) F46 21 Surface Mounted Fluorescent Channel (Mounted on lobby desk for task lighting) PAR30 Spot 10 (1) 150W Metal Halide - CDM150MH/830 (2) 75W Metal Halide CDM75MH/830 (1) 28W T5 for every 3 - F28T5/830 120V 120V 277V 165W 83W 30W Existing Power Density: 1.5 W/sf for decorative lighting and 1.6 W/sf of general lighting. The general lighting for the space meets the 1.8 W/sf set by ASHRAE Standard 90.1. However, the accent lighting exceeds the recommended 1.0 W/sf. 22
Existing Controls: All circuits in serving the lights in this space are control through the time clock via lighting relay panels for 24-hour operation. No dimming is available in this space. Ground Floor 2 nd Floor Design Criteria (Per IESNA Lighting Handbook) Horizontal Illuminance The recommended light level on the work plane is 10 fc. The reception/security desk, however should receive 30fc for reading tasks. 23
Vertical Illuminance The recommended vertical illuminance is 3 fc. This space is highly visible from the outside and features 3-story art/banners. Therefore, greater illuminance is needed to accentuate the banners. An illuminance of 10fc should be available for displays on vertical surfaces. Design Scheme The lighting in the space should accentuate the ceiling height. The 3-story features of the space should be accentuated to create a grand impression that is indicative of CNBC as one of the broadcasting industry s giants. The lighting should look integrated with the architecture as well to create a modernistic impression. The wood wall should also be accented to create a contrast between all the metal finishes within the space. Direct Glare The entire east wall of the lobby is composed of glass. Large amounts of sunlight penetrate the space during the day, therefore, consideration of direct glare from sunlight should be taken into account. Reflected Glare There are VDT screens imbedded in the banners of the lobby, thus reflected glare can be an issue from both artificial and natural light. This is a very big problem because the VDT screens that play programming being done in the studios are directly facing the glass curtain walls. Source/Eye/Task Geometry The VDT screens are intended to be viewed from all parts Of the space, and source/eye/task geometry must try to limit, direct, reflected, and veiling reflections on the screen from the entire space. Appearance of Space and Luminaires This space receives a lot of traffic from both the building occupants and guests for the broadcasting shows. The lighting in the space should reflect great aesthetic quality to complement CNBC s reputation as one of the nation s largest networks. Guests should feel a sense of awe when entering the space. Therefore the lighting should help accent the 3- story banners both during the day and night. Furthermore, the wall behind the banners where the studio door is located should also be washed to direct guests to that area. Color Appearance The colorful banners should be lit with lamps with good color Rendering index of at least 80 to accurately and brightly render its colors. This space is receives high profile traffic, and material used 24
should appear rich and vibrant for aesthetic reasons. Neutral color temperature is necessary so that occupants feel comfortable in the space. A corporate lobby space such as this shouldn t have low CCT lamps similar in residential use, or a very high CCT and have the space appear cold and harsh. Daylight Integration Because of the great amount of natural light available in this space, the integration of daylight in designing of the lighting system can call for dimming of artificial light when required light levels are reached through natural light. Modeling of faces and objects The lobby is where a lot of personal interaction takes Place when building occupants meet with guest or clients. Faces must then be lit evenly to avoid shadows in the face. Points of Interest The entrances to the main studio are located behind the 3-story banners. For easy accessibility to guests, lighting should direct them to these spaces. The wall where the doors are located should be washed to accent them. The reception desk, although a major part of the lobby, shall take a secondary importance compared to the back wall with the studio doors, which are much harder to locate. Maintenance Due to the 39 high ceiling, lamps with longer lamp life should be chosen to reduce the frequency of re-lamping luminaires. It is also best to consider group re-lamping of the luminaires in order to reduce the cost of labor and equipment. (Per ASHRAE Standard 90.1) Power Allowance ASHRAE Standard 90.1 recommends 1.8 W/sf of power for lobbies in office buildings. An additional of up to a maximum of 1.0W/sf to light the artwork displayed in the space. Control Requirements The standard mandates an automatic control device to shut off lighting by time of day basis or through the use of occupancy sensors that shall turn off after 30 minutes of inactivity. Furthermore, each device within an enclosed space shall control only a maximum of 2,500sf for spaces less than 10,000sf. Override switch shall also be provided to override the automatic control device for no more than 4 hours. Switching for this space shall be inaccessible to the public. However, the receptionist should be able to easily control the task lighting on the desk. 25
Parameters Used for Calculations Light Loss Factors Type Maintenance Category Cleaning Interval F27 I Clean, 24 mos. F39 VI Clean, 24 mos. F40 VI Clean, 24 mos. F41 VI Clean, 24 mos. F46 I Clean, 24 mos. RCR RSDD LDD LLD BF Total LLFs 0.26 0.90 0.88 0.90 0.98 0.70 9.5 0.93 0.80 0.90 N/A 0.67 9.5 0.93 0.80 0.75 0.95 0.53 9.5 0.93 0.80 0.74 0.95 0.52 0.26 0.90 0.88.95 0.98 0.74 Assumed Finishes and Reflectance o Ceiling: Material: perforated metal ceiling tiles (Armstrong silver gray) Reflectance: 37% o Lobby Desk: Material: stainless steel (satin finish) (reflectance from color matching) Reflectance: 43% o Floor: o Walls: Material: dark blue terrazzo tiles (reflectance from color matching) Reflectance: 7% Material: paint (Benjamin Moore: day s end) Reflectance: 35% o 3-Story Banners: Material: paint (Benjamin Moore: evening blue, big country blue, cool 26
aqua, York harbor yellow) Reflectance: 8%, 13.2%, 35.8%, 57.1% Reflectance Average: 28.5% o Side Walls: Material: anigure wood veneer (reflectance from color matching) Reflectance: 56% o Glass: Existing Lighting Performance Material: gray tinted monolithic glass Transmittance: 43% Outdoor Visible Light Reflectance: 6% Average Horizontal Illuminance: 2.7 fc (1 above finished floor) 15.5 fc (on lobby reception desk) Average Vertical Illuminance: 2.55 fc 27
Renderings 28
Psuedocolor: Illuminance Psuedocolor: Luminance 29
Illuminance Grid (center of Lobby) Existing Conditions Critique The lobby lightly greatly falls below the recommended light levels while at the same time exceeding the allowable power density. The design criteria of points of interest still remain a consideration for this space where the studio doors are located behind the 3-story art/banners. Through the use of lighting, guests should be directed to areas of interest. Despite very few luminaires in the space due to excess light during the day, the power density still remains very high. The distribution of light, although dramatic, does not place attention to the appropriate places. The entrances to the studios on the right side of the reception desks appear to be ignored. The glass curtain wall side with the columns had more light placed on them. More emphasis was placed on the benches and columns that have no significant role in the space other than for decorative purposes. 30
East Plaza/Façade General Description The East Façade serves as the main point of entry into the building drawing visitors through the plaza. The plaza has an alternating pattern of white and black terrazzo tiles. A pre-formed metal canopy supported by the CNBC signage leads guides occupants to the building entrance. On adjacent sides of the curved tinted glass curtain wall that frame the lobby are metal panels, interrupted by tinted glazed ribbon windows. Trapezoidal planters are scattered throughout the plaza grounds. Dimensions: 110 x 93 (plaza) 1,500sf under the canopy Existing Lighting System Lighting Fixture Schedule Type Quantity Description Lamp Voltage Ballast Watts S1 14 Floor Recessed Adjustable Uplight (1) 70W Metal Halide - 120V 80W S2 26 Floor Recessed Uplight S5 13 Floor Surface Mounted Bollard Path Light CDM70MH/830 (1) 35W Metal Halide - 35MH/Par30/830 (1) 35W Metal Halide - 35MH/Par30/830 120V 120V 38W 38W Existing Power Density: 0.14 W/sf for plaza lighting and 0.75 W/sf under the canopy The power densities in these areas meet standards for outdoor power densities. Existing Controls: All circuits in serving the lights in this space are controlled through the time clock via lighting relay panels to operate from dusk until dawn. 31
Design Criteria (Per IESNA Lighting Handbook) Horizontal Illuminance The recommended light level on the work plane is 5 fc on the building entrance and 0.6 fc for the plaza. Proper illuminance level is needed for safety when walking in the plaza. Vertical Illuminance The recommended vertical illuminance is 1.2 fc. Although slightly higher, this is needed for security camera purposes. Design Scheme The lighting in the plaza should showcase the visible lobby. Lighting shall promote a safe and secure atmosphere during the night. The luminaries should also blend well with the space during the day and be arranged orderly to prevent a disorganized look. The plaza lighting should create a gradual gradient of light, growing brighter as you approach the building entrance. 32
Direct Glare Direct glare can cause visual discomfort to occupants approaching the building. This is an active pedestrian entrance, and direct glare should not take away attention from the entrance. Reflected Glare Reflected glare from the canopy, which is a current issue, can cause visual discomfort to those approaching the building. Source/Eye/Task Geometry To avoid uncomfortable direct and reflected glare to those approaching the building, it is necessary to consider this geometry. Appearance of Space and Luminaires This space receives a lot of traffic from both the building occupants and guests for the broadcasting shows. The lighting in the space should reflect great aesthetic quality to complement CNBC s reputation as one of the nation s largest networks. Moreover, the lighting in the plaza and façade must not take away from the showcased art/banners seen from within the lobby. Areas around the glass looking into the lobby should remain dark in order to create a more dramatic contrast between the visible lobby and the outside surroundings. The overall plaza lighting needs to lead the eyes towards the glass instead of focus it on one exterior surface. Color Appearance Once again, this space receives high profile traffic, and material used should appear rich and vibrant for aesthetic reasons. However, it must not take away from the main focus which are the banners inside the lobby. The lamps that are used to illuminate the canopy and under it should have good CRI because this is where people may congregate and their faces and clothing need good color rendering. CRI for lamps that light the floor of the plaza is not an issue, however, CRI for lamps that light the plants in the planters should be able to render color well. The CCT for all exterior lamps is to remain constant to avoid unsightly changes in lamp color appearances. Modeling of faces and objects For the safety of pedestrians, faces must be properly lit properly to create a sense of security. Shadows For the same reason above, it is important to eliminate shadows for the safety and security of building occupants. Peripheral Detection Proper illuminance should be given so that occupants entering or leaving the building have enough light to be aware of activities 33
occurring in their peripheral vision. This, in turn, provides a sense of security. Points of Interest The entrance to the building should be the brightest exterior surface in order to direct occupants to the proper areas. However, it must remain relatively dimmer than the interior of the lobby to preserve the lobby as the main focal point. Light Pollution/Trespass Light pollution has increasingly been becoming a problem. Luminaires that do not emit light above the horizontal plane should be used to minimize this problem. (Per ASHRAE Standard 90.1) Power Allowance ASHRAE Standard 90.1 recommends 3 W/sf of canopied area for building entrances with canopy, and 0.25 W/sf for the façade. Control Requirements The standard mandates controls through photosensor or astronomical time switch capable of automatically turning off the lights once daylight is available. Parameters Used for Calculations Light Loss Factors Type Maintenance Category Cleaning Interval S1 VI Dirty, 12 Mos. S2 VI Dirty, 12 Mos. S5 IV Dirty, 12 Mos. RCR RSDD LDD LLD BF Total LLFs N/A 0.8 0.75 0.74 0.95 0.42 N/A 0.8 0.75 0.75 0.95 0.43 N/A 0.8 0.72 0.75 0.95 0.41 Assumed Finishes and Reflectance o Canopy: Material: preformed metal (reflectance from color matching) Reflectance: 39.4% o Facade: Material: prefabricated metal panels (reflectance from color matching) Reflectance: 39.4% 34
o Plaza: Material: black and white terrazzo tiles (reflectance from color matching) Reflectance: 4.5%, 73.7% respectively o Glass: Material: gray tinted monolithic glass Transmittance: 43% Outdoor Visible Light Reflectance: 6% Existing Lighting Performance Average Horizontal Illuminance: (above finished floor) Plaza: 1.0 fc Under Awning: 3.2 fc Average Vertical Illuminance: Plaza: 0.76 fc (near entrance) Plaza: 0.00 fc (middle of plaza) Under Awning: 1.7 fc Renderings 35
Psuedocolor: Illuminance Psuedocolor: Luminance 36
Illuminance Grid: Plaza Ground (center) Illuminance Grid: Under Awning 37
Existing Conditions Critique The lighting in the plaza does well in emphasizing the entrance to the building. The lighting on the plaza, however, greatly falls below the vertical illuminance levels. The canopy is the only brightly lit surface; therefore, reflected glare is an issue. Because the power density for the plaza, canopy, and façade are very low, more lighting can be added to address the issue of safety. Furthermore, the exterior lighting of the space does not direct one s focus on the art showcased inside the lobby. Instead, attention is immediately brought to the bright canopy; a canopy which has no decorative purpose. Although it does direct the attention to the entrance, it also takes away from the 3-story art/banners that should be the focus. The 3-story banners mirrors CNBC s name as a leading broadcasting giant in the industry, thus, attention must be drawn to them. A balance must be reached where the banners still stand out, and the canopy and entrance areas are lit to direct occupants, but not draw attention away from the banners. 38
Technical Sources The IESNA Lighting Handbook ASHRAE Standard 90.1 Material Reflectance Sources Benjamin Moore Color Preview Color Palette www.armstrong.com www.gkdmetalfabrics.com www.ppg.com Relevant Computer Files User name: ctc128 P:\AE481W\Technical Assignment 1 Luminaires and IES Files: P:\AE481W\ \Luminaires and IES files Lamps: P:\AE481W\ \Lamps AGI Files, Renderings, Grids: P:\AE481W\ \AGI Files 3D CAD Files: P:\AE481W\ \3D CAD 39