Op-Ed

Support for Photoluminescent Exit Signs

With thousands of safe and economical photoluminescent (PL) exit sign installations in buildings throughout North America, we at Active Safety initially wanted to tar and feather Alex Wilson for the inaccuracies and misconceptions in his feature article “The Evolution of Exit Signs (and Why the Latest is a Bad Idea),”

Vol. 15, No. 11. But after fielding scores of phone calls from A&Es [architects and engineers] for the past few weeks, it is clear that the misperceptions contained in the

EBN article are shared by numerous A&Es.

Now, after sending out countless sample signs and catalogs, we look at the

EBN article—wrong as it may be—as a fantastic opportunity to introduce this highly sustainable technology to more green building advocates. Thank you

EBN. Alex, you can step away from that pot of tar.

As

EBN points out, because of the lighting parameters necessary to support PL exit signs, they may not be the best option for every application. However, experienced A&Es are usually able to configure the lighting fixture schedule and location plan to use PL exit signs in a majority of locations that require exit signs. It’s not that difficult to engineer PL exit signs, but it is a diversion from standard practices and therefore avoided by many A&Es. However, PL exit sign use is growing as stakeholders recognize the safety, economic, and environmental advantages that PL exit signs have over LED and radioactive tritium exit signs: near failsafe, less expensive, non-electrical, no radioactivity, longer lifecycle and possible contribution toward three LEED® credits.

The inaccuracies in the

EBN article could have been avoided by checking with UL, the NFPA [National Fire Protection Association], fire marshals, or A&Es with PL exit sign experience. We sincerely hope that

EBN will formally make the following corrections:

•There is no UL or any other building code that requires facilities using PL exit signs to turn on lights charging the signs before occupancy.

•Properly engineered, PL exit signs can be installed in locations with low-wattage compact fluorescent downlights, occupancy sensors, and timers.

•The energy to charge a PL exit sign will never exceed the energy to power an LED exit sign—unless you add an additional lighting fixture.

With additional research, we’re sure that

EBN will recognize that PL exit signs are a revolutionary sustainable product. Accordingly we suggest that

EBN consider re-listing PL exit signs in

GreenSpec

Michael O’Connell, Sales Engineer

Active Safety Corporation

Murray, Utah

Editors’ response

Thank you for the letter—after receiving it we explored this technology further. We were indeed incorrect about a UL or code requirement to charge photoluminescent exit signs for one hour prior to occupancy, though that possibility was debated in code meetings and is recommended by some code officials—as argued in an article in the September/October 2003 issue of IAEI (the magazine of the International Association of Electrical Inspectors).

However, we stand by the primary argument made in our feature article: that in a well-designed, energy-efficient building interior there may not be the NFPA-required five footcandles of illumination on photoluminescent exit signs. Several of the best lighting designers in the country clearly demonstrated this reality to

EBN using sophisticated computer modeling—and the light levels weren’t just a little shy of the recommended level, but in some cases failed to achieve even two footcandles at typical exit sign height. In other words, we remain concerned that additional lighting fixtures

will be required to satisfy the five-footcandle illumination requirements, or that the lights will have to be on longer to ensure that the exit signs are adequately charged. Innovative lighting designs like those modeled for our article save much more than the two to three watts required by an LED exit sign, the technology that we recommend for most situations.

Published January 2, 2007

(2007, January 2). Support for Photoluminescent Exit Signs. Retrieved from https://www.buildinggreen.com/editorial/support-photoluminescent-exit-signs

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