A visualization of Continuous Daylight Autonomy (cDA)
Why Daylighting: As an (electrical) lighting designer, daylighting is exciting to me for a lot of reasons. There are energy conservation reasons, of course–40% of the electricity consumption in commercial spaces is lighting, and daylight harvesting is a mostly untapped method of reducing that sum. There is evidence that a connection to the outside world is beneficial to the happiness and productivity of the occupants, such as the research conducted by the Heschong Mahone Group on classrooms and commercial office spaces. And, artistically, there’s a tremendous potential to create dynamic sculptures using the sun and building form, and to contribute to the narrative of the architecture.
Know your sDA from your aSE: I just got back from attending the Daylighting Institute at the 2012 Lightfair, which if you have a chance to go is really worth your time. As the LEED sustainable building program becomes the default for high-profile projects, it is pushing daylighting design from the provenance of academic research and a few specialty firms out into the mainstream of standard architectural practice.
Many of the seminars this year revolved around the various daylighting metrics available, whether moment-in-time based metrics such as that found in LEED 2.2, to dynamic metrics such as daylight autonomy (DA), useful daylight illuminace (UDI), and spatial daylight autonomy (sDA). I thought a quick reference guide to the various ways of measuring daylight within the space, with examples, might come in handy for people like myself that are trying to get a handle on all this. The metrics are in approximate order of how established they are within the design community, with metrics that are still under active development like Spatial Daylight Autonomy towards the end. I’ve also created a generic example space to help explain the concepts.
The example space, rendered in AGI
Continue reading “An Overview of Daylighting Metrics, with Examples” »
Here are some pictures from a production of Fool for Love that I designed with Boxcar Theater Company. What’s notable about this production is that I made all of the lighting fixtures. As a site-specific piece, we didn’t want to introduce anything into the performance space that didn’t belong there, such as theatrical lighting equipment. So I modified practical lighting fixtures to work for theatrical purposes. The result was a performance that was truly without a proscenium frame, more raw and intimate than theater, even good theater, is usually. Additional pictures after the break.
Continue reading “Fool for Love with Boxcar Theater Company” »
Click to enlarge.
Here is something you can do on Friday: Now playing at the Hyde Street Studios with Boxcar Theater company, True West by Sam Shepard. This is the first of two plays I’m designing with Boxcar Theater company, and it’s a great show, and I’m very happy with the design. I’ll do a writeup for it on my portfolio site.
True West runs through April 7 and I hope you can make it. More information here.
In my prior post about daylighting analysis, I focused on a ‘representative points’ approach, i.e. taking as typical a mid-morning and mid-afternoon time on the vernal equinox, along with perhaps some bounding points on the winter and summer solstice, and extrapolate the quantity and quality of natural light from there. I was interested to know if a more granular approach would confirm the validity of this method, and what other useful information it might yield besides.
I set the computer up to run a calculation for every 30 minutes, on thirty day intervals throughout the year, for CIE Cloudy, Partly Cloudy, and Clear skies. That made for some 600 radiosity calculations in all, so after queuing all that up, I let my desktop run for about two weeks straight. Continue reading “Incorporating Daylighting in Lighting Design: Part II” »
I went to a lecture by Galen Burrell of Arup, on climate-based daylighting design. One graphic that I particularly liked was the above, showing total energy usage vs. daylight penetration. As you add more windows, you need less electric lighting, but you also have more thermal gain resulting in higher HVAC loads. So daylighting design boils down to an optimization problem, finding the saddle point between those two curves. Neat!
South exposure glazing at 3pm, noon, and 9am.
Prologue: I have been wanting for to better educate myself on daylighting design and analysis, and its coordination with traditional lighting design. Here in California, we have one of the most aggressive energy efficiency codes in the country, Title 24. While this and voluntary measures such as LEED have driven impressive technological advancements in smart, lean building, we’re now a point of diminishing returns because, quite simply, most of the low-hanging fruit is gone. With emerging technologies such as LED lighting still less efficient than good fluorescent lighting (and at three times the cost), there’s no source-efficiency cavalry around the corner. Continue reading “Incorporating Daylighting in Lighting Design: Part I” »
Aerial shot from Adult reading section, looking towards Children's.
If you were wondering what I do all day: Here’s a project that is still very much a work in progress, but the design process is kind of interesting so I though I’d post up where we’re at with it so far. West Berkeley Library is a planned Zero-Net branch library for which I am consulting on the lighting. The architects are Edward Dean and Michael Bulander of Harley Ellis Devereaux. Continue reading “West Berkeley Library, a Zero-Net Facility” »
The Kim Lighting Warp9, a full-cutoff luminaire
Cutoff is dead. Long live Cutoff. Most lighting designers are somewhat familiar with the Cutoff classification system for fixtures. It’s a measure of how well an area or roadway luminaire controls its output, preventing glare from high-angle brightness and wasted polluting light that goes directly up into the atmosphere.
Well. The Illumination Engineering Society (IES) recently deprecated the familiar Full Cutoff/Cutoff/Semi-Cutoff/Non-Cutoff system in favor of BUG ratings. And what, you might ask, in entomological hell are BUG ratings? Briefly, the Backlight-Uplight-Glare rating is a set of three numbers which describe how well a fixture controls and directs the light it emits. It provides a more granular classification of a fixtures performance, correctly scales for LED luminaires that use absolute photometry, and in conjunction with the forthcoming Model Lighting Ordinance addresses excessive lumen packages. Very exciting, but we’ll first look at some examples to explain the motivation for the change.
Continue reading “IES BUG Ratings” »
Or, dispensing with the floor part:
The source would be 2′ long T5 fluorescents. Same perf metal material as before, although I upped the perforation size as I’m not going for a fluid organic effect here.
The lamps could possibly be supported by some kind of tensegrity scheme, which would hopefully reduce the number of wires I need to run to the top. The screen in this case would be simpler, I could probably get away with just riveting it to close it.
Mainly, it becomes a ballast problem. It would have to dim, and dimmable T5 fluorescent ballasts are outrageously expensive. Also, off the top of my head no one makes a 3-lamp ballast for 2′ T5s, so I’d be looking at 2 ballasts, or about $2-300 just on ballasts.
there are some parts that would be difficult to source, such as the 3-way support rod and the lamp sockets, but for the most part this is the simplest to construct.
Hmmm. I’m going to watch House now and drink some beer, and let this one sit for a few days.
Or, I Could Do Something Like This:
In this concept, there would be a helical-spiral perf metal screen which would act as a diffuser. The source would be an MR-16 or similar mounted in the base, pointing up. The perf screen is generated as a parametric surface governed by the following equations:
X(u,v) = cos(u)+1.5*u*sin(u)
Y(u,v) = sin(u)+1.5*u*cos(u)
Z(u,v) = .5*u*v
u ∈ [4, 15], v ∈ [1.5, 27]
Looks complicated, but the shape is just a trapezoid rolled up into a cylinder. I like the moire-interference pattern cast by the overlapping layers of perf metal, but in order to get a nice clean finish on the edges I’d have to wrap them in some kind of metal beading, as well as support the whole thing with vertical rods, and I’m not sure I can do that without welding. So the screen might end up being handmade paper or something like that.