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When retrofitting your business’ lighting, knowing the important terms will help you gain insightful knowledge of how lighting works and what metrics need to be measured in order to accomplish your goals. When you understand key lighting terminology, you can make smarter decisions that impact your business’s aesthetic, energy consumption, and lighting quality.
Measuring Electricity
If one of your primary goals is to lower energy usage, keep in mind the following terms that measure how lighting uses electricity.
Watt (W) is a measure of electrical power. It tells you how much electricity a lighting fixture uses. For example, a 15-watt LED bulb consumes 15 watts of power while it’s turned on.
Kilowatt-hours (kWh) represent energy consumption over time. One kilowatt-hour equals 1,000 watts used for one hour. So, if you use a 15W LED bulb for one hour, it consumes 0.015 kWh. In contrast, a 60W incandescent bulb uses 0.06 kWh in the same amount of time—four times the energy for similar light output.
Lighting and Color
The color of lighting has the biggest impact on the aesthetic and function of a business. It plays a role in how customers or clients view and react to your brand, as well as the productivity of employees.
Color Rendering Index, also known as CRI, measures how accurately a light source reveals colors compared to natural light. The scale runs from 0 to 100.
- CRI of 80-: Colors may appear dull or unnatural, without a lot of definition.
- CRI of 80-90: Colors are acceptable and rendered well.
- CRI of 90+: Reds look vibrant, whites appear neutral, and overall visual clarity improves.
For example: Retail stores and art galleries will require a high CRI of 90+ so customers can accurately see the merchandise. CRI in the 80-90 range is acceptable for places like offices, warehouses, and other commercial uses.
Correlated color temperature (CCT) is measured in Kelvins (K) and describes the color appearance of the light source by how warm or cool the tone is.
- 2200K to 3000K: Warm white (yellowish/orange).
- 3500K to 4100K: Neutral white.
- 5000K to 6500K: Cool white to daylight (bluish tone).
Example: Hospitality spaces, like hotels or restaurants, will typically use warmer lighting to create a relaxing and inviting space. Office spaces and industrial warehouses will most likely use a cooler tone in order to keep employees alert and focused.
Metrics to Measure Lighting
When accurately describing lighting performance, the following terms describe the brightness and direction the lighting is going:
Lumens (lm) measure the total amount of visible light a bulb emits. The higher the lumens, the brighter the light.
Lumens per watt is a measure of luminous efficacy, or how efficiently a light source converts electricity into light. A good retrofit goal is to increase lumens while lowering wattage. For example, a 10W LED bulb might produce 800 lumens, while a 60W incandescent bulb gives off the same amount—making the LED six times more efficient.
Candela (cd): Measures luminous intensity in a particular direction. Think of it like the strength of a flashlight beam.
Foot-candle (FC) is the imperial measurement for illuminance, or how much light reaches a surface. One foot-candle equals one lumen per square foot.
Lux is the metric equivalent: one lumen per square meter.
1 foot-candle = 10.764 lux
For instance, a reading area might require 30 foot-candles, while a hallway may only need 10.
Lighting Functions
Understanding types of lighting helps with functionality and design in a retrofit:
- Directional lighting: Light aimed in a specific direction, often used in accent lighting to draw attention.
- Accent lighting is used to highlight specific areas or objects. Example: A spotlight aimed at a painting or product display in a retail setting.
- General lighting provides uniform illumination throughout a space. Example: Overhead LED panels in an office provide consistent light across the workspace.
- Supplementary lighting adds light to areas where general lighting falls short. Example: A desk lamp used for reading that enhances visibility beyond what ceiling lights provide.
If your organization is considering an LED retrofit we recommend reviewing our Lighting and Product Education Center. We cover the most common types of lighting, their pros and cons, as well as lighting recommendations for different areas of your facility.
Other Key Terms
- High Intensity Discharge (HID) lamps: These are still used in industrial settings but are often replaced by LEDs in retrofits for better efficiency and color control.
- LED (Light Emitting Diode): A highly efficient lighting technology. LEDs use less wattage, have long lifespans, and are available in a wide range of CRI and CCT options. They also come with substantial rebate options.
- Warm-up time: The time it takes for some lamps (like HID) to reach full brightness. LEDs typically have no warm-up time and offer instant illumination.
Wrapping It Up
These essential terms will help you become equipped with the knowledge you need during the retrofitting process. Terms like CRI, wattage, and lumens allow you to choose lighting options wisely so they meet your goals and expectations.
Action Services Group has lighting experts who can advise you on choosing the best lighting for your space. We are standing by to answer your questions, call 610-558-9773 or email [email protected] today!
