From: “LEED and Photoluminescent Exit Signs – Glow in the Dark goes Green”, Active Safety by Michael O’Connell
From a green perspective Photoluminescent Exit Signs are a highly sustainable product that can directly contribute toward securing points in the following LEED Credits:
EA Credit #1 – Energy and Atmosphere: Optimizing Energy Performance
MR Credit #4 – Materials and Resources: Recycled Content
ID Credit #1.1 – Innovation in Design: Exceptional Performance
EA Credit #1 –Energy and Atmosphere: Optimizing Energy Performance
To qualify for this LEED V2.2 Credit (worth up to 10 points) a building project must demonstrate improvement in the proposed building energy performance compared toa baseline criteria specified in ASHRAE/IESNA Standard 90.1, or comply with prescriptive measures of ASHRAE ‘Advanced Energy Design Guide for Small Office Buildings’, or comply with the ‘Basis Criteria and Prescriptive Measures of the Advanced Buildings Benchmark.
More points are awarded to building projects using less energy than “baseline” guidelines prescribed by ASHRAE or the Advanced Buildings Benchmark.
With respect to exit signs, these guidelines are formulated on the basis of installing modern LED exit signs which pull about 5 watts of power. Although the impact of a few exit signs using 5 watts is not significant, larger facilities can employ thousands of exit signs in high and low applications. Recognizing that electrically powered exit signs must be energized 24 hours/day x 365 days/year, a typical large building project with 500 LED exit signs, each using 5 watts of power, burns nearly 22,000 kwh of electricity annually, costing about $3,000 at $0.14/kwh.
Since Photoluminescent Exit Signs are charged from nearby area lighting and require no direct power, there is no related electricity cost. Consequently, Photoluminescent Exit Signs will positively contribute to the calculations that determine the energy efficiency of a building project. Depending upon the number of exit signs in your project, this additional energy savings can be significant in obtaining points toward EA Credit #1.
MR Credit #4 – Materials and Resources
This credit requires that 10% of the dollar value of permanently installed project materials consiste of recycled content. The recycled content value of a material is determined by its adjusted recycled weight (=100% post consumer component weight + 50% pre-consumer component weight) multiplied by the total dollar value of the assembly. Since many types of Photoluminescent Exit Signs are made primarily of metal with high recycled content, these exit signs will contribute handsomely toward this credit.
ID Credit # 1.1 – Innovation in Design: Significant Environmental Benefits
There are two avenues available to obtain Innovation in Design points. Using Photoluminescent Exit Signs works best with the avenue whereby the project team demonstrates a comprehensive approach toward employing a product or technology that has significant environmental benefits not addressed or credited to other LEED categories.
The comprehensive approach targets optimizing the benefits and tradeoffs of an innovation proposal throughout its lifecycle phases: design, procurement, construction, operational and decommissioning. The advantages of Photoluminescednt Exit Signs span all the lifecycle phases with the following environmental benefits:
Fewer Building Materials Required – Reducing activities that pollute air and water, destroy natural habitats and deplete natural resources. Photoluminescent Exit Signs are not electrically powered and therefore do not require the associated metal conduit, wiring and switching equipment that Led exit signs need.
Energy Efficient – Reducing Emissions of Global Warming Ingredients.
Photoluminescent Exit Signs operate on nearby ambient light and are not direct users of electricity like LED exit signs. Therefore, the project will enjoy energy savings, and depending upon the generation source, a corresponding reduction in greenhouse gas emissions, acid rain and radioactive waste.
No Radioactivity. Photoluminescent Exit Signs do not contain radioactive material like tritium exit signs. This author’s opnion is that building products that contain radioactive material have no place in any facility where there are better, sustainable technologies and they sure the heck should not be in LEED certified facilities.
High Percentage of Recycled and Recyclable Materials. Many Photoluminescent Exit Signs are made of recycled aluminum or steel which can be recycled again at decommissioning/disposal. A few components on an LED exit sign can be recycled including batteries, circuit boards and possibly some metal parts. Recycling tritium exit signs can be done only in facilities licensed by the NRC and consists mainly of recovering radioactive material for reuse or disposal. The plastic housings and internals of tritium exit signs are typically not recycled.
No Hazardous Materials or Wastes: Photoluminescent Exit Signs contain no toxic or hazardous materials and are not regulated in any way. Both LED and Tritium exit signs contain hazardous materials whose disposal is regulated. Specifically:
LED exit signs have printed circuit boards (always) and battery back-up packs (usually). These are now considered “universal wastes” by the EPA and are not permitted in municipal landfills.
Tritium exit signs are radioactive and mandated by the Nuclear Regulatory Agency to be routed to a licensed recycle/disposal facility when they expire.
Longer Lifespan. High quality Photoluminescent Exit Signs are rated for a minimum 25 year life span. This is considerably longer than most LED and Tritium exit signs. LED exit sign batteries must be replaced every 3-4 years and their light bars are nominally rated for 50,000 – 70,000 hours (6-8 years). Tritium exit signs are rated for 10, 15 and 20 years but few signs over 10 years are used due to their high cost.
Less Maintenance: Photoluminescent Exit Signs require far less maintenance attention than LED exit signs. Most building codes require that LED exit signs and their backup power supplies be tested monthly and annually – a manpower intensive activity periodically requiring change-out of parts. Photoluminescent Exit Signs have no parts to replace and maintenance consists of dusting and verifying proper operation of nearby charging lights.
For more information on LEED certification, view the following links:
Canada Green Building Council – www.cagbc.org
Accelerates the design and construction of green buildings in Canada
U.S. Green Building Council – www.usgbc.org
Committed to expanding sustainable building practices