[fuligo]

Dumb detectors can have the same problems. I'm not sure if they get contaminated or suffer some kind of other breakdown, but I had to switch out two smoke detectors in recent time due to their propensity for going off on a whim. Of course, normal smoke detectors don't come with the Nest's hefty price tag...

[mscman]

Where were your faulty detectors? My ex-girlfriend's dad used to do testing for a smoke alarm company a while ago. I learned an interesting thing from that. You know what they use to simulate smoke when they test smoke detectors? Hair spray. The fine mist is actually pretty good at tricking the sensor into thinking there are smoke particulates in the air. This also leads to an interesting failure scenario for many home smoke alarms: those close to bathrooms or in women's bedrooms tend to get gunked up with hairspray.

[Casseres]

Hairspray is a bad idea IMO. It will leave residue behind. There are cans of fake smoke you can get at the hardware store. I worked on ships and tested smoke alarms that way.

[Spooky23]

There are different detectors for different applications. Usually the issue with false alarms is the wrong alarm + poor placement.

Ionization smoke detectors have a high false-positive rate in areas like kitchens where you have a lot of particulate matter. Use a photoelectric there.

http://www.consumerreports.org/cro/co-and-smoke-alarms/buyin...