High Bay Lighting FAQ's
What are High Bay Lights?
Generally, any light that hangs 20’ or higher from the ground can be considered a high bay light. The name “high bay” is used because of the traditional use of these lights in industrial or commercial bays. High bay fixtures are often attached to ceilings by chains, hooks, or pendants. They can also be attached directly to the ceiling. What lighting types are available for high bay lights?
- Metal Halide
What fixture types are available for high bay lights?
UFO High Bay Lights
- Round/circular in shape
- Create a spotlight effect with a circular beam of light (hence the UFO reference)
- Easier to control light direction
- Best above 13’ install height
Linear High Bay Lights
- Rectangular in shape
- Wider angle of light beam
- Often good for hallways, aisles, corridors
Wet Location High Bay Lights
- Look like other high bay lights, but are sealed to protect internal components from moisture
- Designed to withstand harsh indoor and outdoor conditions
Where are high bay lights used?
- Industrial and Manufacturing Facilities
- Assembly Lines
- Large Retail Stores
- Recreational facilities, gyms
- Event Centers
- Aircraft hangars
- Parking Garages
What to look for when buying High Bay Lights
Light Color is measured in units called Kelvins. A lower number in Kelvin means the light is warmer and more toward the red scale. This can be good for restaurants and home settings. A higher number in Kelvin, on the other hand, means the light is cooler and more on the blue scale. Cooler lights are more suitable to retail, industrial and commercial applications. 4000 Kelvin and higher can increase productivity and decrease eyestrain, as it more closely mimics daylight. If you are purchasing LED high bay lights, there is a range of options that is larger than other types of lighting.
Efficacy or Lumens Per Watt
Efficacy is a measurement of how efficiently a bulb converts energy into visible light. It is measured in Lumens per Watt. A higher lumen per watt ratio can reduce the number of watts needed to light a space, and result in significant energy savings. Lower efficacy lights are generally less expensive to buy, which makes them attractive. However, over the lifetime of the light, a higher efficacy light will save more than enough energy to offset the higher initial cost and add lifetime savings. Additionally, higher efficacy lights can save on initial cost by providing more visible light from fewer bulbs. For example, a fluorescent high bay light with efficacy of 75 lumens/watt will provide only half the visible light compared to an LED with 150 lumens/watt. You would need twice the number of fluorescent lights as LED’s, which doubles initial cost.
|Light Type||Average Lumens per Watt|
|Fluorescent||Up to 75|
|Induction||Up to 90|
|Metal Halide||Up to 100|
|LED||Up to 190|
Foot candles (fc) are a US measurement used to calculate lighting levels. A foot candle is the illumination of one lumen per square foot of area, with an even distribution. (SI units are measured in lux, or one lumen per square meter.) The number of foot candles needed depends on the type of use of the space being lit. The brighter the space needs to be, the higher number of foot candles are required.
|Parking Garage||10 fc|
|Office Spaces||50 fc|
|Assembly and Factory||70 fc|
|Retail Spaces||80 fc|
|Visually Intensive Work||100 fc|
Color Rendering Index (CRI)
CRI measures the ability of a light source to accurately render colors compared to natural lighting. A higher CRI, the closer the colors will appear to how they appear in natural sunlight. For any applications where color is important, like clothing retail or commercial printing, you will want to look for bulbs with a higher CRI.
Different types of lighting can have different lifespans. As we saw with efficacy, lifespans of bulbs impact both initial purchase cost and costs over time. Less expensive lights, like fluorescent lights, have a shorter lifespan, while LED’s have a much longer lifespan which results in longer replacement times and significant cost savings.
|Type of Light||Average Lifespan|
|Metal Halide||6000-15,000 hours|
|LED||Up to 200,000 hours|
Number of Lights Needed
The size, shape, and use of the space you are lighting will dictate how many lights will be needed. Additionally, as explained above, the efficacy, CRI, cross lighting, and foot candles of the lights themselves, calculating the number of lights needed can be a complex task. Many turn to lighting consultants to help them determine their exact lighting needs. Some manufacturers provide calculators that will assist with determining the number of lights needed using their specific products in your space. Below are some things to take into consideration as you calculate how many lights you need.
The height at which you install high bay lights also impacts the number of lights you will need for your space. As your ceiling height or install height increases, you will need more lumens to adequately light their space.
|Ceiling/Install Height||Generally Recommended Lumens|
How far apart lights are placed has a big impact on the number of lights you will need. A general listing of light spacing is below, but how the space is used will also factor into how closely you space your lights.
Lights will need to be spaced in a way that eliminates dark areas and creates a more uniform lighting throughout the space.
|Ceiling/Install Height||Generally Recommended Spacing|
|10 feet||12-15 feet apart|
|20 feet||15-19 feet apart|
|30 feet||19-29 feet apart|
|40 feet||30-40 feet apart|
Improperly spaced lighting leaves inadequately lit areas over certain workspaces in the below floor plan.
Shadow areas eliminated by using proper light spacing in the below floor plan.
Cross Over Lighting
Cross Over Lighting refers to light coming from multiple directions, which helps to eliminate shadows and give a more even light distribution. Light from at least 3 directions is recommended to avoid light “hot spots” and give an even lighting appearance.
|Shadow from Single Lighting Source||Shadow Mitigated with Crossover Lighting|