Reminder Electric Lighting System Components

Transcription

1 LUMINAIRES Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 1 Reminder Electric Lighting System Components Source lamp and luminaire Path space geometry and reflectances Receiver illuminated task or surface (and eventually the human eye) Controls Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 2 1

2 Reminder Luminaire Types There are six basic categories of luminaires, defined by their light distribution patterns: Direct Semi-direct Indirect Semi-indirect Direct-indirect General diffuse Within these broad categories there are innumerable individual products Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 3 Luminaires Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 4 2

3 Luminaires Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 5 Luminaires Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 6 3

4 Luminaires integrated building design?? scale?? there seems to be no end to the inventiveness of luminaire designers Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 7 Luminaire Tasks Physically hold a lamp (making a safe electrical connection and providing structural support accomplished through a variety of lamp base types) Protect lamp from damage as necessary and appropriate (and perhaps protect occupants from lamps) To the extent required reduce the potential for glare by mitigating lamp brightness as viewed by users of a space (the importance of this task varies with lamp type for instance T-12 versus T-8 versus T-5 fluorescent lamps) For exterior fixtures reduce light pollution (to sky) and/or light trespass (to adjacent properties) Contribute to the aesthetics of a space or place Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 8 4

5 Luminaire Tasks light pollution mitigation light trespass mitigation Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 9 Luminaire Tasks hold, connect, and protect glare mitigation via luminaire lens design Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 10 5

6 Luminaire Tasks danieloverbey.blogspot.com Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 11 Direct Glare Mitigation: Using Maximum Luminance Rules 2500 cd/sq m Maximum luminance recommended for large sources (such as a fluorescent fixture, window, or skylight) 7500 cd/sq m Maximum luminance recommended for small sources (such as a recessed downlight fixture) Design tip: ensure that light sources (including luminaires) are not too bright (as defined above) by reviewing manufacturer s data Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 12 6

7 Controlling Luminaire Luminance at 3100 lumens and substantially less than 1 sq m in area, this bare lamp would very likely to be perceived as a glare source; a luminaire, however, spreads the lumens out and controls where they go all below 2500 target 2500 target luminaire candlepower distribution graphs can help ensure that light sources that are too bright are not included in the proposed design solution Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 13 Glare Mitigation output with potential for direct glare glare-free output output with potential for reflected glare use caution in selecting luminaires Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 14 7

8 Direct Glare Mitigation output with potential for direct glare glare-free output use caution in selecting luminaires this type of luminaire has no output in the direct glare zone Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 15 Reflected Glare Mitigation use caution in selecting and locating luminaires Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 16 8

9 Luminaire Glare Control metal-lux.com/english/products/mtl-l008/mtl-l008.html batwing distribution this type of fixture design has maximum output in the glare-free zone Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 17 Unintended Consequences parabolic louver characteristics provides for tight cutoff of light from lamps reducing fixture brightness (and mitigating glare), but also darkening the edge of a room see next slide for room brightness recommendations luminaire ceiling wall Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 18 9

10 Glare Mitigation: Using Maximum Contrast Rules Suggested Maximum Luminance Ratios (for opaque surfaces under equal illuminance, this becomes the ratio of surface reflectances) 3 : 1 Between task and surround 10 : 1 Between task and more distant surroundings 20 : 1 Between light sources and surroundings 40 : 1 Anywhere in field of view Design tip: ensure that room surfaces are well-illuminated and that sources (luminaires and glazing) are not too bright Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 19 Typical Luminaire Diffusers parabolic louver translucent plastic diffuser egg-crate louver the job of a diffuser is to reduce luminaire brightness by shielding the lamp and/or spreading light out Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 20 10

11 ^^ HDR (high dynamic range) image analysis Glare Analysis Tools sustainabilityworkshop.autodesk.com Radiance (software) image analysis >> radsite.lbl.gov Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 21 More Luminaire Tasks Provide an aesthetic bridge between a lamp (an industrial device) and the architecture of the space House the ballast for gaseous discharge lamps the ballast may on occasion be remotely located (for noise control) or be a part of the lamp assembly (as with CFLs) Perhaps act as an air supply or return device (called a troffer ); by returning room air through a luminaire, heat can be removed from the space load, thus reducing air supply volume (but not AHU cooling load) Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 22 11

12 Luminaire Tasks less ugly more ugly return air provide return air path (troffer) house ballast and mitigate aesthetics Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 23 More Luminaire Tasks Improve lighting system effectiveness and efficiency by directing light that would be lost in the fixture or the spatial arrangement toward a lighted object (this task is becoming increasingly important in the face of climate change) cause effect Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 24 12

13 Source Efficiency Metrics LAMP: luminous efficacy = lamp lumens / lamp watts LUMINAIRE: luminaire efficacy rating = luminaire output lumens / lamp watts LUMINAIRE AND SPACE: coefficient of utilization (CU) = lumens falling on task / lamp lumens Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 25 Meaning of Efficiency Metrics LAMP: luminous efficacy measure of electric input that is lost to heat (versus light) LUMINAIRE: luminaire efficacy rating measure of lamp lumens lost within luminaire (by absorption/inter-reflections) LUMINAIRE AND SPACE: coefficient of utilization (CU) measure of lamp lumens lost in luminaire and in room before reaching task plane Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 26 13

14 Luminaire Efficacy online product data Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 27 Luminaire CU same luminaire a wide range of CU values online product data Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 28 14

15 More Source Efficiency Metrics BALLAST: ballast factor derived from lamp-ballast performance (see next slide) BALLAST: ballast efficacy factor derived from equation (see next slide) Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 29 Ballast Metrics Ballast Factor: lumens with proposed ballast lumens with reference ballast Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 30 15

16 Ballast Metrics: Ballast Efficacy Factor Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 31 Reflected Ceiling Plan a floor plan (cut horizontally through a space) showing elements on/at the ceiling using solid lines (versus the dashed lines usually used for things above the plan cut line); purpose tie down locations and coordinate Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 32 16

17 lighting fixture (for daylighting) some sunlighting is probably just fine in this type occupancy Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 33 You cannot really read, or admire, or be in a room unless natural light is there. We are actually born out of light, you might say. I believe light is the maker of all material. Material is spent light. Louis Kahn All at once you look across a crowded room To see the way that light attaches to a girl And it s one more day up in the canyons And it s one more night in Hollywood A Long December Counting Crows Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 34 17