High Bay light fixtures are generally used in areas with high ceilings or mounting heights greater than 5 meters and are most commonly found in commercial and industrial applications such as warehouses, factories and large open areas with high ceilings. LED high bays are the energy efficient alternative to traditional HID high bays like Mercury Vapour (MV), High Pressure Sodium (HPS) or Metal Halide (MH). Upgrading to quality LED high bay luminaires will improve lux levels safety, and visibility. Building and/or business owners will also benefit from major savings in energy and maintenance costs.
High Bay Lights are used in many commercial and industrial applications to illumine large indoor spaces with ceiling heights greater than 6m. High bay light fixtures are commonly suspended from chains, hooks or pendants but can also be mounted directly to the ceiling / roof. Areas in which high bays are used include: Warehouses, Factories, Workshops, Manufacturing Facilities, Plants, Recreational Facilities, Gyms and more. Traditional high bays typically use mercury vapour, high pressure sodium (HPS) or metal halide lamps. LED high bays now offer a far more energy efficient and long lasting solution to any high bay applications.
LED High Bay luminaires offer many advantages over older technologies including:
The most common reason for retrofitting instead of replacing high bay fixtures is due to budget. Retrofitting an LED high bay costs less upfront than replacing the whole fixture. The disadvantage is that high bay retrofit lamps have a shorter lifespan (due to more limited heat management) than complete high bay luminaires and the available options are limited. Complete LED High Bay luminaires, on the other hand, may cost more upfront but they will last a lot longer, which will save future replacement and maintenance costs which can work out more cost effective long term.
LED high bays do not require a ballast. Traditional high bays use lamps that are driven by a ballast that controls the power in order to start and keep the lamp burning. Retrofit LED high bay lamps, on the other hand, run directly off mains power (220Vac in South Africa). The existing high bay ballast must be removed or bypassed and 220V must be connected directly to the lamp holder before installing the LED retrofit lamp. LED lamps contain an internal driver which converts the incoming power to the correct voltage and current required by the LEDs. If you are replacing an existing high bay fixture with a complete LED high bay luminaire, you simply just need to connect it to mains power.
Good LED high bay luminaires are designed to last for at least 50,000hours. This translates into >11 years if running for 12 hours a day. Cheaper LED high bays may only offer 25,000-30,000 hours while high-end high bays can provide 80,000-100,000 hours. Good suppliers will provide a solid warranty for their products in case of defect or premature failure. 5-year warranties are normally provided for high bays rated for 50,000 hours or more. 3-year warranties are normally provided for life spans of <35,000 hours. A solid LED warranty must cover 24/7 operation. LED high bays can operate well after their rated useful life. This is defined as when the luminaire has lost >30% of its original output. While the high bay may still be working, one must check that lux levels are still above the prescribes safety standards for the area being used.
How long is a piece of string? To find the right size, the right questions must be answered first... There are many factors to consider when choosing the right LED high bay for your application. We have outlined some factors for you to consider so that you can get a better idea of what you need, however, it's always best to talk to an expert. Please contact our sales team if you need any advise of assistance.
New Design or Replacing Existing High Bays:
If you are simply looking to replace existing high bays, then you need to ensure that the LED high bay you use to replace has the correct lumen output (brightness) and light spread (beam angle) to provide enough light to maintain or improve lux levels for the area used. Direct 1:1 replacing of high bays is far more cost effective than a redesign as one can use the existing reticulation and mounting structures. For a new design or new building, one needs to start from scratch and consider all aspects of the project, we touch on some good points here but we recommend speaking to our sales consultants who can assist and even provide lighting design to ensure you get the desired light levels required.
Light Output: Always compare lumen outputs, NOT watts. The higher the efficacy (lumens per watt) the better as it will save more in energy costs. Beam Angle: The higher the mounting height, the narrower the beam angle should be and/or the smaller the spacing of high bays should be. A tighter beam angle will concerntrate more light so that you get more lux on the ground. We offer ranges with 60°, 90° or 120° options to suit. Spacing: The light output, mounting height, beam angle and required lux level will determine the correct spacing. If you have spacing and lux level requirements, then the other factors need to be chosen appropriately. Remember to always have cross-over lighting between the beam spreads of the high bays. This will provide a more even and better-lit environment.
A simple rule of thumb when looking to replace your 400W HID high bay is to look for a high bay that provides at least 20,000 lumens. A 150W LED high bay with an efficacy of 140 lumens per watt (lm/w) will give you 21,000 lumens and will be an excellent replacement. Many customers are impressed at how much brighter the area is than before by following this simple rule of thumb. The increase in brightness is often due to the existing fixtures being old and having experienced a major lumen depreciation over time and the fact that the colour temperature and rendering index of LED high bays improves visual perception of the environment. The beam angle of the LED high bay you chose is also important depending on the application, mounting height and spacing of your existing high bays. Our 150W Diamond-DS LED High Bay is a very popular go-to solution for most applications.
LED high bays can be installed anywhere from 4m to 30m+. The most important things to always consider are the lux level required as well as the spacing, beam angle and of course the lumen output of the LED high bays. The higher the high bays will be installed, the narrower you want the beam angle to be and you will be needing a higher lumen output. A narrow beam angle will help concentrate the light which results in higher lux levels on the ground. If the upper area of the space is not utilised it is best to suspend the high bays as low as possible which will increase lux levels considerably and can save a lot of costs as fewer units may be used to achieve the same effect if the high bays were installed higher up.
Lighting Fact! Lighting follows the inverse square law. This means that the intensity of light is inversely proportional to the square of the distance. Ie. If the distance from the light source is doubled, the object will receive only a quarter of the light (not half, as is easy to assume). The inverse is also true: If you halve the distance to the light source, the light levels will improve 4 fold!
The main difference between high bays and low bays is that high bays are typically used at heights of >6m while low bays are typically used in areas
The spacing of your LED high bays depends on the height, lumen output and beam angle of the high bays you're considering as well as the lux level you need to achieve. It is always best to have cross-over lighting between the beam spreads of the high bays as this will result in a more even and lit environment. See above "What size LED high bay do I need?" for more information.
The required lux levels (luminance) of different areas are defined by a countries Occupational Health and Saftey Standards. In South Africa, these standards are defined in SANS 10114-1:2005 which covers requirements for good lighting and basic guidelines for the design of artificial lighting installations for general indoor locations.
Below are some helpful lux (lx) requirements for common applications where high bays are used: