Not all Smoke Alarms are created equally

Fox News (Memphis, Tennessee) produced a news story that gives light on the differences between Ionisation and Photo Electric smoke alarms. They also carry out an experiment to illustrate the performance of smoke alarms.

In my view the experiment was VERY POORLY conducted and full of inaccurate statements. For example they tried to demonstrate a SLOW SMOULDERING fire by setting fire to news paper and timber a tin bucket. This is NOT a slow smouldering fire!!!

Then they conducted a FAST FLAMING fire using a pan fire with a likely alcohol or petrochemical accelerant.

While it?s easy to criticize the story, the message is important. The following is a copy of the story and the associated video.

MEMPHIS, Tenn. - Every year, about 3,000 people die in house fires and firefighters say most could've walked away if only they had a smoke detector. But FOX13 I-Team reporter Curtis Jay found that not all smoke detectors work the same.

They're not all created equal. You probably don't think much about which smoke detector is in your home or which one you should buy, but you may want to take a second look at your first line of defense.

"The photoelectric picks up heavy smoke or smoke particles from heavy smoke like a smoldering fire, whereas ionization picks up particles from the heat intense, or what we call a clean burning fire," said Jody Dwyer, Germantown fire marshal. "They both do the job, just in different ways."

For a test, FOX13 went to a local hardware store and bought a couple of smoke detectors to see which one worked the best.

With the help of the Germantown Fire Department, firefighters first started a slow burning fire, the most deadly kind.
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In just 15 seconds the ionization detector went off, but it was nearly a full minute later that the photoelectric smoke detector went off.

That was a surprise, since the photoelectric detector is supposed to go off quicker in slow moving fires. That obviously was not the case.

It was a significant length of time, especially when every second counts.

Next, the firefighters started a fast burning fire. The temperature reached nearly 400 degrees. The ionization detector went off in 10 seconds and it claims to be more effective in fast flames.

The photoelectric alarm went off in 23 seconds, a difference of 7 seconds.

In both small and big fires, the ionization smoke detector worked the best in our unscientific tests. But the delay between both methods was a surprise even for some firefighters.

But no matter what, Dwyer warned that just having a smoke detector is better than having none.

"So the important thing is to have a working smoke detector,: said Dwyer. "I think our longest time was, on any smoke detector, 1:10. That's plenty of time for you to wake up and get out and save your family and yourself.

However, Dwyer said that a dual sensor smoke alarm was the best kind to buy. The dual sensor smoke alarm will typically cost about ten dollars more.

If you don't know what kind is in your house, it should say on the front or the back of the smoke detector.

Source: Fox News Memphis - Not all Smoke Alarms are created equally