# Smoke detectors and reaction time



## Red Squirrel (Jun 29, 2009)

I was doing a test of my alarm system and burned some paper inside a pop can to produce smoke, I punched some holes near the bottom for air. 

This was producing quite a bit of smoke, but it took a good half hour before the detector kicked in. I had to close all the doors around to force the smoke up, and even then it took a while, then I held it up to the detector, put it back down and finally after another minute or so it kicked in. At this point my eyes were starting to burn and I had to go take a bit of fresh air. Just to give an idea how much smoke there was. 

I asked them about it and they said it's normal as paper produces mostly carbon monoxide so it was not being detected as well by the smoke detector. Though, I kinda question that because my CO detector never went off and is literally next to where I placed the water bowl that had the can in it. 

They also said I can buy a special can for testing smoke alarms, but I rather just do the real thing and simulate a possible real life situation, obviously a bit unsafe, but I'm here to deal with any issue that happens. Should I be worried that this detector is not adequate enough or do you think it's fine?


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## iminaquagmire (Jul 10, 2010)

There are two different types of smoke detectors. The basic ionization detector is better for fast, flaming fire. Slower smoldering fire is better detected with a photoelectric detector. It is certainly not uncommon for ionization detectors to not go off for 30 minutes or more in some cases. That is why its recommended that one have both kinds installed. The easiest way to do this is a combination unit.

I've been told that the fake smoke isn't good because it can leave a residue on the inside of the detector. Make sure the inside of the detectors are clean by either a quick shot of compressed air or a vacuum. Also, detectors generally have a lifespan of about 10 years. CO detectors should be replaced every 5.


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## pacowilson (Dec 5, 2011)

For the testing of smoke detector, you can ask somebody who smoking cigarette to do the test.

The density of smoke must reach to the trigger level value. Different models and types of smoke detector may with different value.


If you can not make sure about the smoke detector, you also can install the heat detector for fire prevention.


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## user1007 (Sep 23, 2009)

Just saw this post. Just before Christmas a guy a few doors from me fell asleep on his sofa with a cigarette. He had disabled his central system smoke alarm because he kept setting it off. Nobody noticed his place was on fire until flames were swpotted from across the street. The hall smoke detectors went off about the same time. He ended up one crispy critter and died (hopefully never coming around again) about 8 hours later with most of his skin charred off). 

The fire department responded in an impressive manner but did not want to worry about people wandering around so asked us to stay put. They had the fire out in about 10-15 minutes after arrival but the hall was completely filled with smoke for nearly an hour even with huge exhaust fans in the hall windows and exits. Even trying to seal my door with a wet towel, more than enough got in my place to make my eyes burn and tear and set off my smoke alarm. Fortunately it was warm enough I could open a window once the fire was out.

In addition to having to gut and and rebuild a super nice unit the building is going to have to paint the halls on this floor and replace the carpeting. The stench was awful for awhile waiting for insurance adjusters and all before clean-up could start. And all because of a disabled smoke alarm, a fool smoking when he knew he could fall asleep, and sofa materials that go up in flames in seconds. Everybody should watch one of the YouTube flicks showing how fast sofa fabrics, cushions and draperies not treated with fire retardants ignite. 

I didn't really freak out but this is the closest I have ever come to being involved in a fire. Fortunately the firewalls between units held and there was surprisingly little adjacent damage. Even water seemed to bypass the unit underneath and flow to the 7-11 in the corner of the building on the ground floor. A mop and some new ceiling tiles and they were back in business. 

Total irony? Maintenance for the building got the idea they should add battery backup smoke detectors near the central alarm system ones. The central one in my unit did its thing faithfully and blared for 45 minutes. The battery one next to it tests fine when you push the button but never did go off! So it is important to actually test the things somehow.

I hope somebody will post a coherent way to do that? As mentioned, the battery unit squeaks when you press the test button and the battery was fresh. It did not respond to the smoke and it consisted of everything imaginable.


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## Red Squirrel (Jun 29, 2009)

Wow got lucky there.

And yep, that's why I wanted to test with real smoke. You can press the button, or even buy cans that make smoke (though I'm guessing those are good) but nothing beats a real life situation test. 

Though next time I do this test I'll use something other than paper. I also realized how I do need a smoke detector in the lower level, near the kitchen perhaps. If something was to start on fire in that area of the house it would take a while to get to the smoke detector. 

Almost want to get another that is part of my alarm system. The monitoring gives good piece of mind that if something happens and I'm not home I'll be notified and if they can't reach me they send the fire department. They also have CO detectors too.

I've been working on a hvac control system so I'll have temp sensors around the house. I will probably add a feature to my app to send me a notification if it detects a sudden increase in heat on any of them, as it could also be another indicator for a fire.


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