Introduction: The function of high bay lighting is to light surface which are more than 15 feet away. Some common kinds of high bay applications can be seen in gymnasiums, warehouses and factories etc. All lamps which are used in applications are consists of mercury. In recent times, both high intensity fluorescent technologies (HIF) and HID have gained popularity but the performance of HIF technology is understood better in many applications that is which has given HIF opportunity to gain market share. The improved technology of fluorescent lamps and the invention of new HIF fixtures have composed the most cost effective choice as fluorescent lighting for indoor areas like warehouses, big retail stores, factories and athletic facilities (Lighting: HID Versus Fluorescent for High-Bay Lighting, 2007, p 1 para 1).
History of fluorescent lighting: Generally people associate lighting and lamps with incandescent light bulb which was invented by Thomas Alwa Edison and some other inventors. These kinds of bulbs perform on the basis of electricity and filament. When these bulbs are heated by electricity, the filament gets high temperature so it glows and gives light. Fluorescent bulbs like arc and vapor perform differently. The light does not come due to heat; it is produced through the chemical reactions, which happen when the application of electricity is on different gases encircled in a glass void compartment (The History of Fluorescent Lights, 2009, para 1).
In 1857 Alaxandre E. Becquerel discovered the fact of fluorescence and phosphorescence. He imagined the creation of fluorescent tubes as same as they are made presently. He did some experiments on coating electric discharge tubes, which were combined with luminescent materials. This was the procedure which further expanded in fluorescent lamps (The History of Fluorescent Lights, 2009, para 2).
In 1901Peter Cooper Hewitt got exclusive rights on the first mercury vapor lamp (The History of Fluorescent Lights, 2009 para 3). His low pressure mercury arc lamps became the very first of its kind for today’s modern fluorescent type. Edmund Germer discovered a high pressure vapor lamp which helped in producing economical light with less heat. In 1927 he copyrighted an experimental fluorescent lamp. Some historians give Edmund Germer the credit of inventing the first true fluorescent lamp (The History of Fluorescent Lights, 2009, para 7).
T5 Lamps: High lumen fluorescent systems are gaining a lot of popularity where T5 fixtures are presented in 4 and 6 lamps configurations whose effective process can be related to high bay applications. They are flexible systems which are some levels higher than any other high bay applications. It has following characteristics (High Bay lighting Solutions, 2007, p 3, para 1):
* It provides the most light with the help of the fewest lamps.
* It is good for using with occupancy sensors.
* It is ideal for maintaining lamp life in frequently switched applications.
* It has 120-277 volt and 347-480 volt ballasts.
* It can increase lumen output at 35 c ambient temperatures.
* It is specially designed for high bay applications.
* Its technology is very high which can reduce generated heat.
* It consists of thermal technology that can remove heat.
* It has the facility of additional energy savings (High Bay lighting Solutions, 2007, p 3, para 2).
Comparison with HID: HID lamps are thought to be point sources as they throw intense light in a small area. These kinds of lamps can be used for distant purposes such as indoor and outdoor sports facilities, warehouses, factories, where the ceilings are high and street lightings are used (Lighting: HID Versus Fluorescent for High-Bay Lighting, 2007, p 1, para 1).
If we compare HID with HIF lamps some disadvantages of HID lamps have been observed (High Bay lighting Solutions, 2007, p 2, para 2):
* They consume high energy.
* They have warm up and restrike delays as they cannot be related with occupancy censors effectively.
* Their noise is not favorable for quiet ambient
* Their lumen maintenance is very low where significant reduction in lower output can be observed.
* The color is very poor. CRI rates between 60 and 70. Color also varies from one lamp to other lamp.
* Its matching efficiency is less than 80%.
Now if we see benefits of high lumen fluorescent systems it can tell the difference between them and HID (High Bay lighting Solutions, 2007, p 2, para 3):
* HIF are energy efficient. They can save up to 50% energy.
They are instant and they have no warm up time. They have good relation with occupancy sensors so they can save maximum energy.
* Its operation is not noisy instead it is quiet. Its sound has been rated A.
* Its color is excellent. CRI rates between 75 and 85. It does not have any color variation or shift over time.
* Its matching efficiencies are higher than 90% (High Bay lighting Solutions, 2007, p 2, para 3).
While calculating energy efficiency it is necessary to check the number of lamps and as well as watts per lamp (High-Bay Lighting: Opportunities for Mercury Reduction and Energy Efficiency, p 3, para 4). For example four HO T5 lamps or induction fluorescent lamps are needed to create the same amount of light like HID lamp. If the lumens per watt are higher, we will need less electricity for light. If a lighting system uses less Kilowatt hr per year, a facility will use less electricity and it will pay for that (High-Bay Lighting: Opportunities for Mercury Reduction and Energy Efficiency, 2003, p 3, para 4).
Switching from HID lamps to HO T5 fluorescent lamps: It has become a common trend to switch over from HIS lamps to HO T5 lamps that can increase energy efficiency in high bay lighting situation like warehouses etc. HO T5 and induction fluorescents (High-Bay Lighting: Opportunities for Mercury Reduction and Energy Efficiency, 2003, p 2, para 7):
* are capable of insant-on and instant re-strike.
* They can be applied on energy saving occupancy sensors.
* They can be regulated through dimming
* They have lower rate mercury content than HID lamps (High-Bay Lighting: Opportunities for Mercury Reduction and Energy Efficiency, 2003, p 2, para 7).
Recommendations: Facility owners, architects and managers who use high bay lighting applications should opt for the most energetic efficient system where the lowest mercury content is suitable for making and reshaping projects. For improving colors projects should be evaluated carefully. A buyer should consult a lighting professional before buying lighting system in this way the whole project can be assessed to check energy efficiency, lighting level and suitable color depiction. You should tell your lighting professional that your company will like low mercury alternatives (High-Bay Lighting: Opportunities for Mercury Reduction and Energy Efficiency, 2003, p 3, para 9).
Thank you for reading. I am engineer by training and have worked in a variety of manufacturing environments. In the past few years I have been heavily involved in commercial and industrial lighting. I have found out that the fluorescent high bays can be a tremendous improvement in savings and provide better features for each and every manufacturing operation and warehouse.
LED is very hot these days but still a long ways away in my opinion for the industrial and commercial applications. There is some movement in street lighting and some area lighting but LED has not settled yet, it is constantly moving and improving. Although there is a lot of investment in development and new products, potential main-stream buyers are sitting on the sidelines and watching for something to settle.
In his famous book “Crossing the Chasm,”Geoffrey Moore talks about adoption of new technology to the main stream market place. He mentions that there are “Innovators” who take on new things early on in the adoption cycle and then there is the “Early Majority.” I think the Early Majority is waiting on the sidelines. This is my personal observation.
Government provides incentives for the switch over and I have a link on my website to this tremendous resource. If you are waiting on the sidelines for LED you are missing out on what fluorescent high bays can do for you… and do it NOW. I hope you check it out. www.fluorescent-high-bay.com
