Fire & Life Safety: How Many Lights Can You See?

Feb. 6, 2014
A redundant strobe light installation caused headaches for this hotel

I recently ran into someone who had this story regarding an overabundance of strobe lights in a hotel room setting:

We recently inspected a new two-story hotel where each room had its own door opening directly to the outside; in other words, there were no interior hallways. The smoke alarm installed in the handicapped guest room sleeping area was equipped with a built-in 177 candela strobe light and was wired to a second strobe light inside the bathroom. In addition, there was also a fire alarm system strobe light in the bathroom, and another 110 cd. horn-strobe 24 inches down from the ceiling in the sleeping room, right below the smoke alarm. The local fire department inquired as to what was going on with all these strobe lights. It seems the electrician installed the 110 VAC smoke alarms while another company had the contract for the fire alarm system.

First of all, there is no IBC requirement to install a fire alarm system in these types of sprinkled hotels/motels, as long as the guest rooms have the proper fire-rated separation between units. Only hotels and motels having interior corridors must have a fire alarm system to ensure the interior halls serving the guestrooms remain safe exit paths for those exiting their rooms. The single station/interconnected smoke alarms are required regardless of whether the building has interior hallways or not.

Smoke alarms having ADA-compliant strobe lights would also be required in the “sleeping areas” of the designated hearing impaired guest rooms. None of the building codes, nor ADA, require the installation of strobe lights in the guestroom bathrooms. These superfluous bathroom strobes have brought the whole redundancy issue to light (pun intended).

Synchronization Issues

After delving further into this situation, I found that the fire inspector brought up compliance with the rule that requires synchronization of three or more strobe lights in “the field of view.” Technically, in the above-described scenario, there are potentially four strobe lights within the field of view, which suggests — per NFPA 72 — that they be synchronized. In fact, the two fire alarm system strobe lights were synchronized to each other, and the other two smoke alarm strobe lights were synchronized to each other — meaning it would be impossible for someone to witness three flashes per second, which is the intent of the rule. Therefore, a discussion with the code official could be had regarding compliance with the letter of the law, vs. the intent of the law.

While you are pondering how that would go, consider that this may have been prevented by an experienced plan reviewer bringing this situation to the attention of the building owner or the architect/engineer of record. The IBC’s building and fire codes require that plans first be presented to the architect or engineer for them to approve before plans are submitted for the permit.

The electrical contractor and the alarm contractor were both dutifully fulfilling their contract and cannot be held responsible for the overall design of the building; however, another professional could have spotted this redundancy (i.e. supplemental work) long before the inspector started questioning the combined flash rate. And, the fire department might also be wondering how the guests will respond if half the strobes are flashing in their room and half are not.

If the strobe light synchronization issue cannot be determined to be acceptable, there are only two remedies left, and neither of them are going to make the property owner happy. Someone is going to either pay for the removal of redundant equipment, as well as the covering of holes where extra strobe lights used to be; or the system must somehow be reconfigured. Seeing that the fire alarm system devices are actually supplemental, the system strobes could be removed; but, to keep the building’s fire alarm system operation compliant, the fire alarm system strobe light from the bathroom could be removed and the sleeping room horn-strobe replaced with a horn only.

Then, the ADA guest room’s strobes could be wired into the fire alarm system’s NAC, so that a general alarm would cause the guest room’s two remaining strobe(s) to flash when the guest room’s fire alarm system horn sounded. For code compliance, activation of the guest room’s smoke alarm would cause the smoke alarm to sound and flash along with the supplemental bathroom strobe. After the guest(s) has fled to the outside, activation of the sprinkler head in that guest room would cause the supplemental fire alarm system to alert the fire department as well as alert the other guests/occupants.

The smoke alarm’s installation instructions would need to be consulted as to how to properly wire the strobes for this dual use. Lastly, the holes where the system strobe light(s) used to be would have to be covered over. If an addressable relay is required to activate the two remaining strobes, the bathroom’s old fire alarm system strobe electrical box could be used to mount this relay — which would mean no patching or covering unneeded boxes.

Greg Kessinger is SD&I’s fire alarm and codes expert and a regular contributor. Send him your fire & life safety questions at [email protected].