Often when clients take the first step in planning a new or renovated space, lighting may not be at the forefront of their thoughts or plans. Other concerns quickly move to the top of the priority list such as design, function, space usage, and budget. Yet in the recesses of their minds, they know lighting plays a key role in the design. It contributes not only to the atmosphere and environment of a space, it aids in wayfinding, safety, and increased work productivity.
When you boil it all down, lighting is a technical art and a science. It is used to make an environment highly appealing and functional. When it is used correctly, lighting provides aesthetical elements that motivate, energize, and even calm those who use a facility. Keep in mind that lighting today is much more efficient and cost effective. Engineers and architects calculate the amount of daylight received in an internal space along with the planned lighting to determine if there is adequate benefit to the lighting design. This calculation combined with other key factors such as surface materials, furniture, paint, and wall textures help to determine the effect lighting will have on a designed space.
So with these entry facts in mind, where should you start in regards to providing a good lighting design? Usually, the best place to start is with the basics and with learning about the various light sources and how they work to create a more productive environment. It is always wise to express your needs and desires up front to the lighting engineer, who will be helping you design your facility.
It is also important to understand the options you have regarding available lighting fixtures and lamp sources. By planning your design for the right kind of illumination, you’ll have a better understanding of what the space is going to look like when it is completed. Plus, the right lighting makes a tremendous statement about how your building and employees will function and work together.
The following is an overview of lighting sources, fixtures, and even the problems that may need to be addressed with older fixtures. This simple but very important information also answers questions that include: What is the color temperature (Kelvin) rating of the bulb? What is the color-rendering index (CRI) that determines if colors in a room are truly the colors the eye perceives? This very basic information will help you think through your lighting choices for every area of your new or renovated facility.
Just the Basics —
Lumen output, color temperatures, CRI ratings, beam spread, lamp life depreciation, and rated lamp life can all dramatically affect your design. However, with the help of photometric software, you can visualize what a proposed design will look like even before it’s started.
- Lumen – The total amount of visible light emitted from a source in a particular direction. The higher the lumens the brighter the light source is. Typically one lumen equals one candela (or foot-candle). A candela is equivalent to the light emitted from a single candle burning.
- Color Temperature (Kelvin) – This determines the “warmness” or “coolness” of a particular lamp measured in Kelvin’s. The lower Kelvin ratings give a warmer appearance. The higher Kelvin ratings give a cooler appearance. Warmer colors typically emit a more orange to yellow appearance while cooler colors typically emit a more blue to pink appearance. Daylight is a mixture of both cool and warm colors.
- Color Rendering Index (CRI) – The ability of a lamp to render the color of an object in a normal and natural way. Typically measured from 0-100. The higher the rating, the better the color appearance of an object. Lower ratings may give an object a false color appearance (a beige wall may look gray under certain lighting, for example)
- Beam Spread – The total angle of a projected beam of light.
- Lamp Life Depreciation – This measures the overall lumen depreciation level over the life of a particular lamp.
- Rated Lamp Life – The actual number of hours a particular lamp will burn before failing
- Photometric – Actual candela (foot-candle) plots that can be placed on a floor plan for a particular light fixture. There are thousands of different types of photometric files that are specific to a particular fixture. These files are called .IES files, which are certified by the Illuminating Engineering Society of North America (IESNA) and are entered into lighting calculation software.
Types of Light Sources
There are a wide variety of light sources available to illuminate a particular space. However, there is no “one size fits all” category. Some sources are better suited for certain environments rather than others.
- Fluorescent – The most commonly and widely used light source available today. They can be found in a wide variety of different types of fixtures: 2×2, 1×4, 2×4, 4×4, 4’ strips, downlighting, undercabinet and decorative lighting.
- Incandescent – Commonly found in floor and table lamps, downlighting, and flood lighting. This lighting is very inefficient in regards to power consumption and is being phased out.
- Halogen – Commonly found in small, decorative fixtures, smaller downlights, landscape lighting and floor lamps. These sources can also be found in house lighting for theaters and sanctuaries.
- High Intensity Discharge (HID) – Commonly found in exterior fixtures consisting of Metal Halide, Low Pressure Sodium or High Pressure Sodium light sources.
- Light Emitting Diode (LED) – An alternative to fluorescent light sources as the technology continues to improve and prices drop. Commonly found in a wide variety of interior and exterior fixtures due to the best “bang for the buck” in regards to energy consumption versus lumen output.
- Induction – This source is similar to fluorescent lamp, except it doesn’t have electrodes as part of the fixture. Therefore, these sources have a much longer lamp life than any other source available. However, they’re cost prohibitive and limited in applications and lamp wattage.
You don’t have to be limited to just on/off switching to control light levels in a space. Dimming or dual level switching is a common practice to control different light levels. Daylight harvesting can be used to switch off or dim lighting near windows. When they’re not in use, occupancy/vacancy sensors switch off lights. Furthermore, Building Automation Systems (BAS) can be tied into lighting systems for seamless building wide control, even remotely
Providing control to automatically switch off lighting when it isn’t needed saves the owner money on their energy bill. Control devices are also eligible for incentives and rebates from many different power companies around the country.
One of the best and most abundant sources of illumination is daylight. Bringing more daylight into a space will reduce the amount of artificial illumination needed. Roof penetrating “Solar Tubes” with internal mirrors and lensed reflectors bring in a surprising amount of daylight from such a small footprint. Skylights and large windows are another great way to bring in large amounts of daylight. Building orientation and landscaping are also an important factor in regards to the amount of daylight that can be brought into a space.
Picking the right illumination source early in the design process is only part of the solution. Coordinating with the architect and interior designer in regards to the space design is critical. Most of the design criteria can be summed up in five simple questions:
Who – Who will be using this space? Input from the end user is always a valuable resource. Ask about a typical day for the space and what type of people may occupy. Also ask about any existing lighting issues that need to be resolved.
What – What will the space be used for? Different lighting levels may be needed for different scenarios. For example, a classroom could be used for children, adults or both.
Where – Where will this space be located? Is it on the perimeter of a building where day lighting could be utilized? Or is it in a dark basement with a low ceiling? It’s also important to know which jurisdiction the space falls under. Some areas of the country, California for example, are much more strict in regards to energy consumption which will affect the lighting design.
When – Will this space be used mostly during the day, night, week, weekends or 24/7? Knowing when the space will be occupied will help determine lighting control of the space.
Why – Why is the space being designed a certain way? Are there moveable partitions or furniture that can be moved to alter the space? By knowing this, it will help determine the switching of the lighting.
Take a moment to look up at the lighting in your surrounding space. See anything that looks strange?
- Different colored lamps
- Lamps that are burned out
- Bugs, dust, and debris in the lenses
- Reflectors that aren’t clean
- Fixtures that are switched on when no one is around
Each one of these factors contributes to an environment where the lighting is not ideal. Not only can these eventually put a strain on your eyes, they can also affect the mood of an employee. Remember up front research is essential and is preparation for a well-designed structure and space. It is necessary in order to get a good idea of what the space is going to look like before the design is even started. By following these methods, you and your client will have a better understanding as to what to expect once the lights are switched on for the first time.