| Photoluminescence is a complex word that | | | | days a year. Add in the cost of replacing light |
| describes a rather simple phenomenon - a | | | | bulbs, back-up batteries and repairing faulty wiring |
| product's ability to produce light without the aid of | | | | and, for a large corporation, and the cost |
| commercial power sources such as electricity and | | | | difference can amount to thousands of dollars a |
| batteries. In scientific terms, this phenomenon | | | | year. In addition to being maintenance free, the |
| occurs when an object absorbs photons from | | | | safety signs have an average life span of 25 |
| ambient light and then re-emits the photons in | | | | years. |
| darkened surroundings, creating a lighting effect | | | | In trimming power usage and maintenance costs, |
| that ranges from ambent to bright depending on | | | | tritium, compact fluorescent and LED exit signs |
| the object's absorption ability. From a quantum | | | | are also cost effective solutions to incandescent |
| mechanics viewpoint, the object moves from a | | | | safety signs, but the last two are not |
| high energy state to a low energy state, | | | | maintenance free and all three have a shorter life |
| re-emitting the photons until it loses its light. | | | | span than photoluminescent signs. The average |
| These objects are often called "self-sustaining" | | | | lifespan for tritium exit signs is 10-20 years, while |
| because they produce their own energy, a | | | | the life span of LED and compact fluorescent |
| perfect example of which can be found in the | | | | signs is roughly eleven years and roughly six |
| most commercially popular of all such products - | | | | years, respectively. Photoluminescent signs are |
| photoluminescent exit signs. | | | | also easy to move if egress paths change, |
| Companies that are committed to going green | | | | whereas LED and compact fluorescent signs |
| and saving money have popularized these safety | | | | require re-wiring. Compared to the competition, |
| signs in the corporate sector. The exit signs play | | | | the exit signs are the soundest long-term |
| a role in the U.S. General Services Administration's | | | | environmental and monetary investment. |
| plan for sustainable design principles, which seeks | | | | According to a popular photoluminescent safety |
| to minimize non-renewable energy consumption. | | | | sign company, the ten-year operating cost for |
| The signs are also a part of Victoria, Australia's | | | | one if its exit signs, including labor and installation, |
| Department of Sustainability and Environment's | | | | is $111.00. Comparatively, the ten-year operating |
| plan to pursue environmentally friendly urban | | | | cost of a tritium exit sign is estimated at $190.00, |
| construction. In addition to preserving | | | | while the ten-year operating cost for individual |
| non-renewable energy, the signs are bright, | | | | LED, compact fluorescent and incandescent exit |
| recyclable, non-toxic and, unlike traditional safety | | | | signs rises to $370.00, $894.00 and $1,465.00, |
| signs, non-radioactive. | | | | respectively. |
| The significance of the exit signs to companies | | | | Most companies that sell photoluminescent safety |
| that are going green is obvious, but even for | | | | signs sell other self-sustaining signage as well, |
| companies that have yet to go green, switching | | | | including fire hose and fire extinguisher signs, |
| from incandescent safety signs to signs that are | | | | stairwell signs, direction arrows and |
| more energy efficient reduces operating costs. | | | | photoluminescent marking tape for identifying |
| Incandescent exit signs burn 24 hours a day, 365 | | | | pathways in darkened surroundings. |