Smoke Detector Sensitivity.

[house92]

I have a couple of battery-powered smoke detectors that have been up since the 1980s. One is about 12 feet from the oven, and it will occasionally set it off. I can also blow out a match underneath, and that sets them off. Some might call that sensitive, but it’s what I am accustomed to.

A few weeks ago, I ordered a couple more battery-powered smoke/co alarms to put in other areas; they were two for $30. The light and test button works perfectly. Yesterday, I decided to give it a test and blew out a large candle a few inches from it. It put off a lot of smoke, but to my surprise, the alarm didn’t immediately go off. I actually had to light and blow out again before it went off.

Does this sound typical with modern detectors? I have read that some are designed not to give false alarms, which I assume means they are less sensitive, but I like them sensitive. Will they work appropriately if there is a real fire, or does the room have to be burned down around you before it goes off? Does it sound like
My new ones are normal or defective?

 

[pjones]

Sounds about right for an ionization type alarm. They are better at detecting hot and fast fires. The components are cheeper to produce therefore cheeper to buy the device. These are the most commonly sold units in stores.

Photoelectric type alarms are faster at detecting the slow smoldering fires (most typical type fires in homes) but are less commonly found on the shelf.

It’s good to have both type sensors. Some detectors have dual sensors built in. Be careful though if the package says dual sensor because not all of them are photoelectric/ionization units, some are ionization/carbon monoxide combo units.

 

[house92]

Ionization may be more common some places, but all I see here is a large number of photoelectric types. You mention the smoldering fire that is most typical in home fires. Could you describe a smoldering fire? How is that different from fires the ionization types detect?