Your city’s fire department has concluded an inspection of your building and it passes with flying colors except one: your outdoor atrium is missing a few exit signs at key points. There are no available electrical conduits, so after a quick Google search you discover battery operated exit signs and conclude this must be the solution.
The short answer is no. Though most commercial exit signs today use energy efficient LED strips (which consume less than 3-5 watts of electricity) even a fully charged, heavy duty battery would keep the sign lit for only a day at most.
Exit sign batteries are only meant for emergency situations. When your building’s AC electrical power is working normally, these plastic exit signs draw power via wiring either embedded within the wall or in an exposed aluminum raceway.
The sign stays illuminated as long as there is an AC feed running to it. In this mode the battery will be on standby, trickle charging at full capacity with minimal memory loss. When AC power fails a surge protector cuts off power to the sign and the switching circuits automatically change over to emergency battery power.
Hence, it is a battery operated exit sign but not in the sense that the layman might infer from a quick search on the Internet.
Though battery operated exit signs may not exist, these non-electrical alternatives will do the job just fine. Best of all, photoluminescent and self-luminous exit signs require no maintenance during their operational lifespan.
Some pre-1960 buildings may still have backup generators or central batteries still in operation. Back in the day, exit signage and emergency lighting, which used incandescent bulbs instead of LEDs, were linked in a parallel circuit on each floor. Emergency units of this time had no battery, and would rely on these standby power sources to allow occupants enough time to find the egress points.
Some modern buildings still use this AC-Only method, but in greater emergencies like an earthquake or hurricane these circuits could be compromised. By having a dedicated battery in each unit you greatly reduce this possibility.
However, battery powered signs should not be mistaken as stand-alone units.
Self Powered Exit Sign – aka ‘self luminous’, these signs contain a glowing green hydrogen gas called tritium. Though tritium has a very small radioactive background signature, it is perfectly safe and requires no electricity or ambient light to remain illuminated. These signs last up to 20 years and require no maintenance.
Glow In The Dark Exit Sign – aka ‘photoluminescent’, this is the perfect tritium sign substitute for customers that want a cheaper, non-toxic alternative. So long as light falls evenly on the sign’s glowing substrate when the building is occupied, these signs will comply with all local, state and UL guidelines.
Call 800-480-0707 to learn more about our selection of tritium and glow in the dark exit signs. We're ready to get you back on the road to compliance!
By Aaron Downes