Author Amy Anderson
A smoke alarm milestone birthday party!
No kidding, I’m passionate about fire protection! To prove it, I could tell you stories about the damage I have seen from various failures from freezes to fire pump cooling to what happens when a fire hydrant’s weep holes are clogged…. But instead, I will tell you about smoke alarms!
Although it’s still new in my head, my home just turned 10 years old. The decade has seen the replacement of two household appliances and at least one HVAC repair… now what? A paint and décor refresh? Maybe, but that’s not what the fire protection engineer is thinking! It’s time to replace the smoke alarms!
Aside: strictly speaking, in the world of UL and NFPA, smoke alarms and detectors are not the same thing. (Yes, I know what the aisle sign at the home improvement store says!) A smoke alarm is a stand-alone device with a sensor, control components, and an alarm notification appliance all together in one unit, and it’s powered from a battery located inside the unit or obtained at the point of installation (hard-wired). A smoke detector is a one-job device that only does smoke-detecting; it must be connected as part of a fire alarm or building alarm system for noise to be made and other magic to happen. Detectors get their power via the alarm control panel. This article is all about smoke alarms.
There have been some important and interesting advances in the smoke alarm standard and technology in the past few years that make replacing or upgrading smoke alarms worth looking at, even if they’re not yet 10. Especially if you have had trouble with nuisance alarms, read on…
Today’s home fires burn hotter and faster than those of decades ago due to an increase in lightweight construction, open floor plans, and synthetic materials in the contents of a home. Escape time is but a fraction of what it once was. Fires will reach flashover 8 times faster(and that’s from a report dated 12 years ago: New Science Fire Safety Journal, Issue 1, UL, 2012).
The standard that most smoke alarms are built to in the US is UL 217, Smoke Alarms. In 2018, UL released important technical changes to that standard. Included were new criteria to reduce nuisance alarms. This is a notable change, because nuisance alarms, especially those due to cooking, are the #1 reason why residential occupants disable their smoke alarms. Smoke alarms were not operating or were intentionally disabled in almost half (46%) of home fires.
Also included in the updates to UL 217 are new fire tests that alarms have to respond to. These include a flaming polyurethane foam test and a smoldering polyurethane foam test. These are intended to ensure alarms have a sensitivity to flaming and smoldering fires involving materials representative of today’s homes’ contents.
Look for alarms that are UL Listed, UL Certified, or that were tested to UL 217 and labeled by a reputable third-party organization like Intertek. The labels may look like one of the three in the image below.
Different markings on new smoke alarms that indicate they have been certified to be in accordance with UL.
Technology
10-year batteries
There are 10-year batteries available, even as back-ups for hardwired smoke alarms. Never have to change a battery over the life of the alarm? Yes, please! *Alarms still need to be tested according to manufacturer’s instructions, even if you never have to touch or change the battery.
Wireless Interconnect
Interconnected smoke alarms are a good call for increased fire safety. With interconnected alarms, if one goes off, they all go off. This increases your time to escape with earlier warning, and means that wherever you are in the house, you are notified. It used to be the only way this was done was with hard-wired alarms. Hard wiring is harder to pull off for a retrofit situation. With wirelessly-interconnected smoke alarms, you can have the benefits of interconnection without the wiring project.
Smart Alarms
For the techno-savvy with smart homes outfitted with the likes of “ringers” or “nesters,” there are smart smoke alarms and alarm listeners. The app on a subscriber’s phone can be notified of an alarm. On some, a false alarm can be silenced from the phone app.
Other Considerations
If there are fuel-fired or fuel-burning appliances (ranges, dryers, furnace, fireplaces…), don’t forget about carbon monoxide detection. Carbon monoxide (CO) alarms are available either as stand-alone alarms or combination smoke and CO alarms.
Does anyone in the residence have a hearing impairment? There are alarms equipped with strobes or alarms that can be interconnected with a strobe. There are also devices that listen for a smoke detector; if a nearby smoke alarm sounds, the listener activates a light and vibration for a bed or pillow.
Two rows of smoke alarms; older on the left to newer on the right. The main advances over the years have been on the circuit boards and microprocessors and are harder to see. The largest round objects are the sounder and detection unit(s). Spot the alarm with two detection units! It is a combination ionization and photoelectric type smoke alarm. All of the others are ionization-type smoke alarms.
So have a look at your smoke alarms. The manufacture date can be found on the back. If it has no date, it is most assuredly at least 10, if not 20+ years old; replace it!
NFPA Fire Prevention Week™ is coming up October 6-12, 2024. This year’s campaign is “Smoke alarms: Make them work for you!™”
If you have a fire case or loss where smoke alarms may have been at issue, call fire protection engineer Amy Anderson!
Amy Anderson, PE, CFEI, has a Bachelor of Science in Chemical Engineering from Clemson University and is a licensed Professional Engineer in Fire Protection, as well as a Certified Fire and Explosion Investigator. Amy has over 20 years of engineering experience including property loss prevention engineering specializing in fire protection, chemical and pharmaceutical facilities. She has partnered with clients to identify, assess, avoid, and reduce risk at their commercial and industrial properties. Additionally, she has assisted with the development of building and fire protection specifications, reviewed plans and performed site visits. She has reviewed project documents for compliance with applicable standards – construction, fire protection, process, and combustible dust hazards. Amy is a member of the National Association of Fire Investigators, the Society of Fire Protection Engineers, the National Fire Protection Association and the American Institute of Chemical Engineers.
