What Is the Difference Between Low and High Bay Lights?

Bay lights are a type of commercial lighting that provides high wattage outputs. Their high lumen and wattage output allows them to illuminate from higher ceilings. Two classes of bay lights exist, low bay and high bay. But, what's the difference?

The classification tells the buyer what ceiling height the bay light should mount on. Low and high bay lights have different characteristics that make them suitable for different applications.

Typically, high bay lights are applicable in any large area with a ceiling height greater than 20 feet. In contrast, low bay fixtures are for large rooms with a ceiling height between 12 and 20 feet. This is because of the wattage, lumen, and beam angle differences between the two.

Wattage and Lumens

The measure of wattage and lumens in bay lights determines the brightness and concentration of the light spread. Wattage is a measure of the power that the bulb consumes, while lumens measure the amount of light output emitted by the bulb. When choosing bay lights, pay attention to these metrics to ensure proper lighting of your space.

High bay lights typically have a wattage of 150W or above, while low bays more often have wattages between 60W and 100W. Higher wattages draw more power, but provide a stronger, more robust light source.

Low bay lights have fewer lumens because they lose less light in the shorter distance traveled between the fixture and the floor. High bays have higher lumen outputs to compensate for the larger distances they have to cast light over. The typical lumen count for high bays is 15,000 or more, while low bay lights range between 8,000 and 15,000 lumens.

Beam Angles

As for beam angles, high bays typically have narrower beam angles, ranging from 50 to 90 to 120 degrees. This is because at a higher ceiling height, the light needs to be more concentrated to reach the full distance to the floor. To do this, high bay lights use special deep reflectors that focus their light downwards and prevent lighting overlap.

Low bay lights have wider beam angles, typically 120 degrees or more. The wider span of light illuminates a larger area of floor space and allows you to use less fixtures in total. Low bay lights have shallower and more diffused lenses that spread and scatter light evenly both downward and outward.

Mounting

The two main ways to mount bay lights on a ceiling are surface and suspended. Surface mounting attaches the fixture directly to the ceiling, while suspended mounting hangs the fixture from the ceiling. Methods of suspension include cables, cords, hooks, chains, rods, and more.

High bay light fixtures usually have suspension mounting capabilities because of the nature of the ceilings they fit on. At heights over 20 feet, the lights usually need to hang from support beams or exposed wiring systems. This prevents them from needing to attach directly to a solid ceiling.

Low bays can be both surface and suspended mounted. Surface mounting allows the fixtures to be further out of the way in spaces with slightly lower ceilings. But if they do hang, the mounting attachments often have a more aesthetic appearance since they are closer to the floor and more visible.

Spacing

Depending on the ceiling height, the ideal spacing for low and high bay lights is different. The closer fixtures are, the less risk of shadows, but too many close fixtures can create blinding light.

For low bays, you should ideally space the fixtures 12-14 feet apart for optimal lighting. High bay fixtures mounted at heights of 20-25 feet can be 15 feet to 25 feet apart. At greater heights of 30-45 feet, fixtures can be 30-40 feet apart as long as they have high wattage and lumen metrics to compensate for it.

High bays need to be powerful enough and adequately spaced to achieve cross-lighting, which eliminates shadows and glare. Otherwise, the beams will not cast even light, leaving unlit spaces in between each one. In general, bay lights should have the same space between them as the ceiling height of the room they are in.

Applications

Low bay fixtures are common in everyday commercial spaces, with typical applications including retail stores, grocery stores, and workshops. You are more likely to see high bay lights in commercial and industrial spaces like warehouses, factories, and hangars.

The two main types of high bays are UFO high bays and linear high bays. UFO high bays are circular fixtures, while linear high bays are long and rectangular. Whether a space has long aisles or specific stations that need direct illumination, each type has its benefits.

Understanding the types of bay lights are important to avoid using the wrong fixture in your space. A low bay light hung from too high of a ceiling will not provide enough light for the space. High bay lights hung too low can flood a space with too much brightness and cause eye strain. Also, operating overpowered lights drives up expenses.

LED Bulbs

In general, high bays use more power and are more expensive to operate, so to mitigate that, you can use LED bulbs. LEDs are energy efficient, meaning they waste less power to produce better quality light. Opposed to traditional lighting, LED high bay lighting contributes more to energy savings and cost efficiency.

LED low bay lighting is equally as useful, as it also offers versatile color temperatures and anti-glare technology. If you’re looking for new bay lighting or upgrading your old metal halide lights, consider LEDs. They are the most well-rounded and highly recommended light bulbs on the market.

Shop HomElectrical to find LED linear high bays, UFO high bays, and more!