Advantages of LED Lighting in Industrial and Hazardous Environments

 

 

Contributed by Justin Grubbs, P.E. – I&E Department Manager

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Advantages of LED Lighting in Industrial and Hazardous Environments

Advantages of LED Lighting in Industrial and Hazardous Environments

Technology continues to develop and improve in the electronics industry. Solid state electronics continually become more and more energy efficient, smaller in size, and more cost effective to manufacture. The advancements made in this field translate to a wide variety of electrical components. One of these is energy-efficient lighting such as light emitting diode (LED) luminaires. LED lighting has a great number of benefits over traditional High-intensity Discharge (HID) lighting such as Metal Halide or High Pressure Sodium lamps, the main benefits being a large increase in energy efficiency and the life of the lamp.

In an industrial hazardous environment, there can be a large amount of time spent to change a bulb in a traditional HID luminaire. The amount of time spent by maintenance personnel to acquire the correct replacement bulb, fill out hot work permits, job hazard analysis, execute lock out tag out procedures, locate equipment needed such as a man lift, and physically change the bulb adds up over the life of the fixture. This is a very important task as lack of sufficient lighting is a safety concern and can lead to a hazardous condition. For a traditional Metal Halide lamp operated for 12 hours a day, the bulb will need to be replaced an average of every 2.5 years. LED lighting is rated to maintain an acceptable light output for 13.7 years when operated 12 hours a day at an ambient temperature of 131°F, this goes up to 45.7 years at an ambient temperature of 77°F.

The initial cost investment of LED luminaires is approximately 35-40% more, however they consume approximately 20% less energy than a comparable HID luminaire. Additionally, the cost of other materials for the installation of an LED lighting system is much less than that of an HID system. Since the load of LED luminaires is less than HID luminaires, there are fewer feeder breakers needed, fewer lighting contactors needed, and smaller cable can be used which translates to taking up less space in cable trays and using smaller conduit and fittings.

As an example installation, take a project needing a relatively small area of illumination such as a barge/ship dock which is classified as an NEC Class 1, Division 2, group C&D area. Assume that a quantity of 30 Metal Halide HID flood light luminaires rated at 250W are sufficient for the lighting requirements of this area. Comparably, a quantity of 30 LED luminaires rated at 149W will also be sufficient for the lighting needed. The given cost variables are as follows:

  • Cost of LED luminaire is 38% more than HID
  • Maintenance time to change 1 bulb is 4 man-hours total (including permitting and LOTO) at a rate of $60/hour
  • The lighting operates 12 hours a day
  • Replacement HID lamps are $12
  • Energy cost is $0.06/kWhr

The annual energy savings with LED luminaires will be just under $1,100, the annual lamp and maintenance savings will be $3,000. The additional initial investment of the LED luminaires over the HID version will be returned in energy and maintenance savings after 1.5 years. The LED fixtures will completely pay for themselves after 5.3 years, and are rated to continue to operate for another 8.4 years before needing maintenance (in modern fixtures, changing an LED cluster is the same amount of man-hours as changing a traditional bulb). This is for a worst case constant ambient temperature of 131°F; for an ambient temperature of 77°F, it will be 40.4 years after the LEDs have completely paid for themselves before maintenance is needed.

The above example does not take into account the cost reduction in materials needed for installation of the LED luminaires. In this project example, if the luminaires are installed on a 120V system, 4 circuits would be needed for the HID version, whereas only 2 circuits would be needed for the LED version. This results in less breakers purchased, smaller wire/conduit/cable tray needed, less photocells, and fewer lighting contactor circuits. All of these will result in reduced construction labor and material costs.

To summarize, the technology of hazardous area LED luminaires has come a long way since their inception. They continue to become lower in cost, increasingly more energy efficient, and have various configurations of lighting clusters so that the distribution of light can vary from a large oval shape, to a long narrow beam, or an intense spot light. LEDs can also be specified as being a full spectrum cool white or warm white, rather than the light spectrum limitations of Metal Halide and High Pressure Sodium HID lighting. Though the initial investment of LED luminaires is more than comparable HID lighting, an LED installation will have a long-term significant cost savings over HID.

References:

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Justin Grubbs H+M Industrial EPC

Justin Grubbs, P.E. – I&E Department Manager at H+M Industrial EPC

B.S. in Electrical Engineering

Justin has more than 7 years of industrial engineering, construction and commissioning experience. He has experience with designing, engineering, leading I&E construction, developing plant control documents, directing commissioning efforts, overseeing instrumentation specifications, validating engineering data, specifying I&E material and training operations personnel.

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