Use of LED Lamps To Improve Health

Today’s New York Times has an article on several manufacturers’ new LED products that are intended to improve wakefulness, sleep, focus, and other aspects of daily life and health. The article appears on both the business and technology pages, but not on the health page, and I think that’s appropriate. Although there are testimonials by the consumers of some of these products, there’s no discussion about any peer reviewed science behind them. In fact, about two-thirds of the way through the article the author finally gets to the fact that, “Researchers are still determining how spectrum and intensity of light affect the brain.” So, the article is an uncritical look at new LED products that make health claims. We shouldn’t rely only on the claims of the manufacturers, though – remember the claims of 100,000 hour lifetimes for LED lamps?

I’m not saying that we know nothing about how light affects us, because we know quite a bit. The question is, “Do we know enough to properly and safely integrate that information into our design practice?” and there things become uncertain. So, before accepting the claims of manufacturers, or making the same claims to clients, it’s important for designers to be up to date on the current state of research and to understand the strength of the findings, as well as how (and if) those findings can be folded into a design.

There are a few web sites that I find useful for keeping up to date. The first is the Health and Vision page of the Lighting Research Center’s web site, which has links to many of their recently published research papers. The second is the Research page of USAI Lighting’s web site. This page provides links to a mix of newspaper articles and scholarly publications on a variety of topics connected to LED lighting. The third is the Research page of the IES web site. Finally, members if the IES can download copies of Leucos, and non-members can purchase copies.

LEDs continue to revolutionize the lighting industry. Most manufacturers have ended research and development for incandescent and fluorescent products. OLEDs are increasing in efficacy and prices are dropping, while new technologies (such as light emitting plasma and quantum dots) are on the horizon or already here. To preserve their client’s money, the occupant’s health and safety, and their own reputations, designers need to make sure that they don’t get swept up in the possibilities that are marketed to them before the facts are in.

“Celebrating Pratt Authors” Comments

Here are my comments from last night’s “Celebrating Pratt Authors” event.

Let me say a few words about my book and than I’ll move on. One of the things that drive me to write “Designing With Light” is missing content in other lighting design books. I come from the theatre-both my undergraduate and graduate degrees are in design for the stage, and I worked in the theatre for over a decade before transitioning to architectural lighting. The other two common paths to becoming a lighting designer are from work as an architect or as an electrical engineer. Until now, as far as I can tell, lighting design books have been written by people with those two backgrounds. They do a fine job of discussing how to light architecture and how to calculate illuminance, but none of them actually address the issue of design. None of them discuss how to think about light as a design element in a space, or how to use light to create the desired atmosphere, environment, or ambiance. That’s the void I wanted to fill.

Some of you may know that the United Nations has designated 2015 as the International Year of Light. I want to build on this by saying a few words about the importance of light and lighting design. There’s an old saying, “out of sight, out of mind” but with lighting design the truth is actually closer to “within sight, out of mind.” Too often people ignore or are unaware of the potential that lighting design offers because as long as they can see they’re satisfied. Many people only notice light when it’s beautiful, as with a sunset, or when it’s an impairment, as when there’s not enough light to do what they want to do. Yet, while only a small percentage of people are aware of the lighting in their surroundings, 100% of people are affected by that lighting.

Sight is, without a doubt, our most important sense. Research shows that about 80% of our sensory input, learning, and activities are related to vision.

Our visual interaction with the world, and has two components. The first is target or object identification. “I see and apple,” is an example of object identification. However, our minds are much more sophisticated than that. We don’t stop at object identification. We’re not really aware of it, but we automatically go on to evaluate our visual target and its relationship to the surrounding visual field, to our previous experience, and to our expectations. This second component of vision is perception-the identification, organization and interpretation of sensory input. Perception is directly affected by the way light reveals the world to us. Can we see the texture of a material or not? Is the color as expected or is it distorted? Can we see the three-dimensionality or does the object appear flattened? Are details visible or are they hidden in shadow? Lighting design matters, in part, because it affects our perception.

The lighting requirements for object identification in terms of brightness, color, direction, etc. are minimal. However, the effect light has on our perception is huge. Perception causes us to form opinions about, and have intellectual and emotional reactions to, everything we see.

If I were to say that I want to take you to a romantic French restaurant, every one of you immediately has a mental image of that space. You may have a mental picture of the color palette of the room, or the ceiling height, or the spacing of the tables. That image varies from person to person, but there is a remarkable amount of commonality in our expectations. For example, I’ll bet that in your restaurant there’s a candle on the table, that the lighting is dim, and that the wood is dark and polished.

If we walked into a restaurant that we have been told is romantic and find it illuminated like a classroom, the perceptual dissonance between our expectations and our experience would cause us to immediately reject the notion that we were in a romantic restaurant. We would declare that the lighting design was a failure. We would, perhaps, extend the idea of failure to the interior design and, depending on the strength of our emotional response, maybe even to the food. Lighting matters, and understanding how expectations of the users affect their perception is one aspect of creating a successful lighting design.

This is something that I emphasize to my students all of the time – you must understand the intended look and feel of the space before you can light it. I also emphasize that they must understand the distribution of light in three dimensions, not just in a two-dimensional plan view.

To control the three dimensional distribution of light requires an understanding of the many types of lighting fixtures that are available, and of the light sources that they use. To control those light sources we have to know about dimming and control systems and technology. The body of knowledge required to create a lighting design is very large.

And, it’s getting larger every year. New lighting technologies such as LEDs and OLEDs have some unique properties. To use them well we have to expand our understanding of issues such as color and control technologies. Add to that the fact that energy conservation codes compel us to think much more carefully and creatively about what we do and how we do it because we’re given so little electrical power to realize our design goals.

Add all of this up and we find that lighting design is hard! It requires a solid grounding in light sources, fixtures, controls, and codes. All of that technical expertise has to be combined with a broad understanding of architecture, interior design, lighting techniques, and aesthetics to turn a mental vision or a rendering into a realized design.

I get very excited when I talk about light and lighting, but I’m frustrated, too. Only about 10% of design and construction projects include a lighting designer on their team. For the other 90% of projects, the lighting design is handled by the architect, the interior designer, or the electrical engineer. Yet academia is not providing the lighting education future designers need.

I’ll use Pratt as an example. Not only is lighting design not a required course in the any of the architecture programs, it isn’t even an elective. Students have to go to the Interior Design department if they want a semester of lighting, but that course is going to be eliminated within a few years as the Interior Design department reorganizes. Pratt is just a single example of what I think is an overall disregard or failure to understand the way light affects our experience of the built environment, and the need to teach future designers how to address the entire visual experience. This, of course, takes us right back to “within sight, out of mind.” But, good enough lighting isn’t good enough.

So, in this International Year of Light, I want all of you to think about and talk about the importance of good lighting in your homes, at work, an in the other places you spend your time. If you teach architecture or engineering or interior design, I urge you to give lighting design a place on the curriculum. If you’re a student I want you to demand that lighting design be made a part of your education. The International Year of Light has set the stage, but it’s up to us to act, to raise the importance we place on good lighting.

With LEDs, Knowledge is Power

I’ve been hired to review an architect’s lighting design and then design an appropriate control system. The fixtures selected are all LED products by a manufacturer that falls into the high-end residential/economy commercial range of quality and price. The cut sheets are extremely frustrating. After nearly a decade of LED lighting, and with all of the progress the industry has made in setting standards so that designers and specifiers know what they’re getting, this manufacturer still tells us nothing. What basic information is missing?

Lamp life. The only information even remotely connected to lamp life is the statement that the fixture is covered under a five-year warranty. There’s nothing else. Not a word. How much light, compared to initial output, can we expect at that five-year mark? We have no idea.

LEDs do not fail like other lamps do. They gradually dim as they age. At what point is the light output so low that we’d say the lamp is no longer useful? Right now the answer is when the light output has fallen to 70% of the initial output (often referred to as L70), although many designers prefer to use 80% of initial output (referred to as L80). This is calculated using a procedure developed by the IES and designated as LM-80 (details are here and here). What we want, at a minimum, is the IES LM-80 calculation of lamp life to 70% of initial output. L80 data would be even better.

Warranty. The warranty is not on the manufacturer’s web site so, although we’re told that it is good for five years, we have no information about what is covered and what is excluded.

LED manufacturer. With all other lamp types the designer chooses the exact lamp for the project. Criteria such as initial lumen output, mean lumen output, lamp life, color temperature, CRI, and the manufacturer’s reputation for quality are all valid considerations. We have standards that allow designers to make valid comparisons between LED products, too, but we can do that only if that information is generated and shared. I suspect that this fixture manufacturer uses LEDs from a several manufacturers based on the best price available, and that the performance of those LEDs varies widely.

Color consistency. The cut sheet says that the standard applied to their LED selection is, “minimum 3-step color binning.” We are left to infer that means three-step MacAdam Ellipses. A one-step MacAdam Ellipse describes a region on a chromaticity diagram or color space where the edges of the ellipse represent a just noticeable difference from the color at the center (additional information on MacAdam Ellipses is here and here). The data is usually plotted on the CIE 1931 (x, y) chromaticity diagram. The diagram below shows 10-step MacAdam Ellipses.

"CIExy1931 MacAdam". Licensed under CC BY-SA 3.0 via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:CIExy1931_MacAdam.png#/media/File:CIExy1931_MacAdam.png — “CIExy1931 MacAdam”. Licensed under CC BY-SA 3.0 via Wikimedia Commons – http://commons.wikimedia.org/wiki/File:CIExy1931_MacAdam.png#/media/File:CIExy1931_MacAdam.png

The color variation within a three-step ellipse would be noticeable to over 99% of the population. Worse, though, is that a three-step ellipse is the minimum, not the maximum. Knowing this, the designer should have no expectation of color consistency from one fixture to another.

Photometrics. The cut sheet contains no information about the optical performance of the fixture. IES files are available, but it’s very difficult to look at the array of numbers and understand performance, which is why the good manufacturers include photometric information on their documentation, including candlepower distribution curves and CU tables.

Part of my review will be pointing out the lack of data about the specified fixtures and recommending several alternates by manufacturers who provide the information necessary to evaluate their products.

IALD Set To Launch CLD Credential

After five years of planning the IALD is set to begin accepting applications for the newly created Certified Lighting Designer (CLD) credential. The CLD credential is similar to the LC (Lighting Certified) credential in that it is meant to demonstrate lighting design competency. Unlike the LC, the CLD credential will be awarded based on a portfolio review that demonstrates proficiency in seven areas of professional practice rather than by passing a written test. The other difference between CLD and LC is that the CLD will only be awarded individuals with at least three years of experience as a lead designer. This means that some people who have earned an LC (sales reps, for example) will not be eligible for the CLD.

Why does this matter? First, the LC credential carries some weight, mainly because since 2009 the GSA has required the lead lighting designer on U.S. government projects to be Lighting Certified. However, many designers are unhappy that people who aren’t practicing lighting designers can hold an LC credential. By limiting the CLD to working designers, the IALD hopes it will be seen as attesting to the holder’s skills as a lighting designer, not just their knowledge about lighting in general.

Second, lighting design is in some ways the redheaded stepchild of the architectural design professions. Lighting design is not licensed, meaning that anyone can say they’re a lighting designer. As a result, lighting design is provided by electrical engineers, architects, interior designers, sales people, and manufacturers who have widely varying education and training, and with widely varying degrees of success. The CLD could be a means of identifying who is a lighting designer and who is not.

The key to the success of this project is public awareness. If the IALD only talks about CLD to the lighting design community it will be nothing more than letters following a person’s name on their business card. Building owners and other clients have to understand the value that professional lighting designers can bring to a project, and have to insist that the design team includes a professional lighting designer. Architects and interior designers have to understand the role of a lighting designer and be willing to tell their clients that a professional lighting designer is an important part of the design team who is worth the additional fee. If, through the CLD, the IALD is able to raise awareness about lighting design in those who can benefit from it, it will have been well worth the effort.

Starting A New Design

I’m between classes at Pratt, so I’ll have to be brief. It’s the time in the semester when my students start to feel overwhelmed. After talking about vision, light, psychology, design, lamps, color, and light fixtures they’re about to start working on designing projects for class. The most common question is something like, “How can I possibly organize all of this information and start to make meaningful design decisions? I need to pick a light fixture, then I need to pick a lamp for that fixture, then I need to lay out the fixtures to arrive at the lighting that I want, right?”

Wrong! A lighting design doesn’t come from the lighting fixture, so design decisions shouldn’t start there. In a push-me-pull-you kind of way the first questions are always about the end result. Rather than choose a fixture and follow the light down into the room, what we need to do is understand the lighting requirements and follow the light up to the lamp and luminaire. How do you want the space to look and feel? What lighting techniques can help achieve that look? Is there an overarching thematic element that needs to be included? How can we express the lighting goals in terms like intensity, color, and distribution? The answers to those questions should start to lead the designer to requirements for the fixture/lamp combination, and to the number of fixture types required to implement the design.

I explain that it’s not always a linear process, and that a certain amount of trial and error is part of any design. “Does this fixture give me the distribution and intensity I need?” isn’t always a yes/no question that can be answered by looking at a cut sheet. Sections may have to be studied, calculations run, different lamps and accessories considered, always with the end goal in mind.

Yes it’s hard. So hard, in fact, that some people spend several years studying light and design at the college level before getting their first job, only to discover that there’s so much more to learn! If you have a passion for light and design, though, trust me it’s worth it.

Happy International Year of Light 2015

The United Nations has proclaimed that 2015 is the International Year of Light and Light Based Technologies, also referred to as IYL 2015. 2015 is the anniversary of quite a few notable discoveries about light. The UN resolution recognizes “the works on optics by Ibn Al-Haytham in 1015, the notion of light as a wave proposed by Fresnel in 1815, the electromagnetic theory of light propagation proposed by Maxwell in 1865, Einstein’s theory of the photoelectric effect in 1905 and of the embedding of light in cosmology through general relativity in 1915, the discovery of the cosmic microwave background by Penzias and Wilson, and Kao’s achievements concerning the transmission of light in fibers for optical communication, both in 1965.”

By focusing on the topic of light science and its applications, the UN hopes to raise global awareness about how light-based technologies promote sustainable development and provide solutions to challenges in energy, education, agriculture and health. It’s an exciting idea, and I hope that we see a lot of activity surrounding light and lighting design in the profession, allied professions, and the media. It’s a great opportunity for the IALD, IES, manufacturers, etc. to raise their profile, raise the profile of lighting design, and educate people about the advantages of well designed lighting. Unfortunately, as of today very few activities have been announced and none of them are activities or events related to lighting in the built environment (not counting annual events, such as LightFair, that would happen anyway). If you have any contacts within these organizations, urge them to take advantage of this special year.

Measuring the Value of Lighting Design

The Lighting Research Center at Rensselaer Polytechnic Institute recently published a short video in which LRC director Mark S. Rea discusses the costs and benefits of lighting. Here it is.

If you set aside the plugs for the LRC, his statements, and those in his book Value Metrics For Better Lighting, are similar to what I’ve said throughout Designing With Light, which is that it’s the quality of the light and lighting design that are of primary significance while the amount of light that is delivered is secondary. Therefore, the true value of the lighting design is found in the design’s success in meeting the multiple requirements of the owner and the occupants of the space, not in the cost of hardware and installation.

Unfortunately, there are several factors that have created resistance to placing value on thoughtful, appropriately designed lighting. The first is that most people simply do not see light (pun intended). For far too many people, if the light is bright enough for them to see what they’re doing it is acceptable and little or no judgment is made regarding the other factors of lighting design, such as color rendering, providing visual interest, overall effect on occupants, etc. I find that if I show clients or students the difference between light that is adequate for vision and light that creates an appropriate atmosphere or environment they can see it and appreciate the difference. It is also a surprise to them that lighting design can make such a difference in a space.

The second factor is that project budgets are set in dollars with no little or no allowance made for the quality of the design. I have often worked on projects where the project budget and the lighting equipment budget have been set, although design work has barely begun. I understand that a client only has so much money to spend and that has to be respected. However, 1) No bean counter in the world can predict what the design team will develop. Budgets are more appropriately set in coordination with the design team after the design team understands the full extent of the client’s needs and desires. Then, if the projected cost exceeds the client’s budget, informed decisions can be made to pull back on certain aspects of the building’s design or to allocate more money to construct the building the client wants. 2) Spending more money up front on efficient lamps and fixtures, and on controls, can more than pay for itself in savings on energy and maintenance.

Another factor is that we value what we can measure. Since the early 1900s the lighting design community has invested a great deal in determining how to measure light and on how much light is required for “visual tasks.” Those two aspects became the criteria for evaluating lighting design, and are still presented as primary in many lighting textbooks. In the 1970s John Flynn and others began to study how light can affect the impressions one forms of a space. Later research examined the relationship between a lighting design and those occupying the lighted space including: the affect on worker productivity, absenteeism, and worker retention; student learning outcomes and test scores; retail sales; a light source’s spectrum and clarity of vision; and light’s affect on sleep cycles and other aspects of health. This research has shown over and over again that intelligent, thoughtful, appropriate lighting design can have a significant effect on the occupants and on the owner’s bottom line, whether that bottom line is to make more money, increase student success, or improve health.

Knowledgeable lighting designers can bring so much more to a building than just illumination, yet illumination and lighting design remain synonymous to most of our colleagues and clients. That is part of the reason only about ten percent of construction projects have a lighting designer on the team. Lighting designers and lighting design professional organizations need to do a much better job of educating design team members and our clients about quality lighting design, what it is, and why it matters.

Promoting Lighting Design

By some estimates less then 10 percent of construction and renovation projects include a professional lighting designer on the design team. Why? Who’s looking after the lighting design? What can the lighting design community do about it?

The reasons projects go forward without a lighting designer range from the owner’s lack of understanding of what a lighting designer does to the architect’s desire to keep fees low. These are usually coupled with the belief that other team members can take care of the lighting just as well as well as a lighting designer. The “others” who may provide some or all of the lighting design include the architect, interior designer, electrical engineer, electrical contractor, and lighting salesperson. These other professions can act as lighting designers because the practice of lighting is so young and is unlicensed.

Why should architects and building owners hire a lighting designer? My first answer is, “You’re hiring experts in every other aspect of building design and construction, so why would you NOT hire an expert in lighting, too? Don’t you want the building to look as good as you imagine it will?” My other answers are:

Research has shown that the benefits of high quality lighting design include increased sales, worker performance, and student test scores.
Professional lighting designers develop unique designs specifically for each project. They know more about light and lighting, put more time and effort into designing the lighting, and will produce better results than any other team member.
The lighting industry is moving and changing faster today than at any time since the invention of the light bulb. Lighting designers invest an enormous amount of time and energy keeping up to date on new light sources, energy codes, control systems and the like. No other team member is as well informed about the current state of the field.

What can the lighting industry to do promote the use of lighting designers? It seems to me that our professional organizations, especially the IES and IALD, have to take the lead here because individuals can’t have enough impact. Both organizations do a lot of work within the industry, but I don’t see any outreach to the real decision makers. What could they do? Here are a two thoughts:

Provide articles to AIA and other professional publications promoting the benefits of working with lighting designers.
Present seminars and staff booths at conventions of AIA, SCUP, Retail Design Institute and others to promote lighting design.

What do you think? What can we do to promote lighting design?

IES Releases RP-31-14 Recommended Practice for the Economic Analysis of Lighting

The Illuminating Engineering Society has released a new Recommended Practice. RP-31-14 Recommended Practice for the Economic Analysis of Lighting is now available as a PDF download or soft back from the IES Online Store. From the IES:

Good lighting should be responsive to the needs of the user. Among those needs are the aesthetic and the visual, as admitted in the oft-quoted “lighting is both a science and an art.” But the user also has economic needs. In fact, it is the economic needs that often drive the decision making process when lighting systems are designed and purchased.

This recommended practice is written from the point of view that “economic analysis” is not the same as “how to beat the budget.” Rather than considering economic analysis as the antithesis of engineering or artistic analysis, is should be thought of as subsuming these other needs. When a competent lighting professional takes care of economic needs, in conjunction with the artistic, engineering, and other needs, it increases the likelihood a project will have success and longevity. Financial considerations ad demonstrated through an accurate lighting financial analysis are important, but other elements such as aesthetics, human visual performance resulting from a lighting system appropriate to a given task, and other considerations involved in lighting for the human and natural environment are of equal importance.

Fixture Cost Frustration

One of my clients has expressed frustration with the caveats I place at the end of my lighting fixture budget. Why can’t I give the client a simple budget estimate? The answer is that fixture manufacturers don’t have a manufacturer’s suggested retail price (MSRP) for their products, which is something we’ve all come to expect for products ranging from potato chips to cars. We all know that things we want to buy have an MSRP or list price and it’s up to the seller to decide whether or not to sell at a lower price.

However, with lighting equipment the sales representative and the manufacturer collaborate to establish pricing for each project (see chapter 9). Larger projects with more luminaires will usually pay less per luminaire. This can be frustrating for everyone. It’s hard to develop a reliable fixture cost database when fixture costs are variable.

Another issue with pricing from the sales rep is that it is usually dealer net, distributor net, or DN pricing. This means that the luminaire price the sales rep gives to the designer is the price that the electrical distributor will pay the manufacturer. It does not include the electrical distributor’s markup for overhead and profit, nor does it include possible markups by the electrical contractor and/or the general contractor. It is up to the lighting designer to estimate the total markup(s) as well as taxes, shipping and such, and add that amount to the projected lighting fixture budget, but designers have no direct knowledge of what markup these firms will add, nor do we have any control over their markups. The result is that I wind up footnoting my budget with notes like markup percentages are estimated, pricing is based on cost estimates provided by sales representative, and pricing is based on projects of similar size and scope.

Finally, as I explained here, the fixtures that I specify may not be purchased for the project. Once substitutions enter the picture another layer of mystery is added. Yes, it’s complicated. Here’s a flow chart that tries to explain the flow of information (denoted by question marks) and money (denoted by dollar signs) of design and sales relationships. See chapter 9 for a full explanation.