Written by Reid Poling, MS, EI, LEED AP® BD+C
What is there to lighting? Picture it. You walk into a room and can’t see, so you flip on a switch, right? Or you walk into a public space like your office, or a store and the lights are just on. You can see just fine so you think nothing of it and go about your business.
However, you certainly notice when there’s no light. You might even notice when there’s too much and it hurts your eyes. My intention is to help illuminate you, pun intended, on just how sophisticated lighting and lighting design can be.
My name is Reid Poling, and I am a lighting designer. I’ve been doing this in practice for over three years now and studied lighting and lighting measurement in college. I earned my master’s degree with a focus in lighting. I’m not sure I can count myself an expert just yet, but I think I know enough to pass on what all goes into designing a lighting system for a building, or even a street.
A good start for a lighting design is understanding how much light you want or need in an application. There are tools to help determine this. The Illuminating Engineering Society, or IES, has published recommended light levels for any number of applications. Many institutions, cities, or companies will also have their own standards, based on previous experience or research into what has worked for them in the past.
Once you have an idea of how much light you need, you can start thinking about how to achieve it. It’s important to consider the features of your space. Are there any architectural features that need special lighting, or provide an option to “hide” lights, or affect the reflection of light in the space? How well a wall or floor or ceiling can reflect light greatly affects your ability to achieve your desired light levels. That also helps determine what type of lighting you can use. Do you want to use direct light, where the light comes directly out of the fixture into the space? Or do you want to use indirect light, which utilizes reflection to get light where you want it? These are all good conversations that go on with the architect and the owner in picking out your light fixtures. There are then computer programs that can create a model of your space and calculate the light levels you should expect with the lighting solution you pick.
Some of the other things to consider throughout design refer to the comfort of the lighting. Glare is probably the biggest. That indirect lighting, I mentioned earlier is a good solution for avoiding glare because you don’t see the light source of the fixture. Some metrics are used to measure glare and can be calculated using software when glare is a concern.
Another metric to consider is called color temperature. I’m sure we’ve all seen lights that are more yellow in tone, and some that are bluer, especially in LEDs. This is called color temperature and just means how “warm” or “cool” a light appears. Color temperature has become a big topic of research and conversation in the lighting community lately, as we start to understand how this relates to human circadian rhythms or our “internal clock.” We’re starting to learn that certain light wavelengths, or colors of light, affect our bodies’ release of different hormones, which can affect our health. Maybe you’ve heard of eyeglasses that block blue light, this is a similar conversation happening about the color temperature in lights. Cooler lights have more blue light, which is now something to consider if you’re going to have people under that light for long periods. Blue light is also more “glare-y” at night and not a good solution for outdoor lighting like the streetlights by your house. Warmer temperatures appear less intense.
Other things to consider are Color Rendering Index, which explains how well a light fixture renders color. Have you ever been in a store, and can’t quite tell what color that shirt is? That’s CRI.
We also need to consider controls of lights. Anymore, it’s so much more than on and off. Many building codes now require automatic occupancy controls, or even daylighting controls to turn lights off if you’re by a window and have enough sunlight. Dimming lights are very common, and now with advances in LED technology, we have more options in changing colors or even changing color temperatures of “white” light.
This is by no means an exhaustive look at designing a lighting system, but hopefully, this can give you a new perspective of what typically goes into a lighting design. Not all spaces are “designed”, and truly don’t have a lot of thought put into them. Hopefully, these are the spaces where you notice the lighting, and how bad it is. In a way, if you don’t notice the lighting, for good or bad, that can be considered a successful design. That means it’s comfortable. Then, of course, there are the designs that are meant to be noticed, because they’re treated artistically and are a part of the architecture. Regardless, hopefully, this gives you an idea and a little more respect of just how much thought can go into those little things that help you see and live out your life comfortably.