Product: Smoke Alarm
WiFi smoke alarm   (+3)  [vote for, against]
A smoke alarm that notifies nearby smoke alarms

The idea is for a smoke alarm that can broadcast a short-range signal to trigger nearby smoke alarms when it's activated. The power (range) and frequency used would be user-selectable. Suitable for retro-fitting apartments or homes with bedrooms upstairs and down.

Ancillary products could work off the same signal to automatically call the fire department, flash lights, activate exterior alarms or shake beds.

(The term "WiFi" is used for convenience)
-- phoenix, Jun 07 2003

(?) EMS Group
[Shz, Oct 04 2004, last modified Oct 21 2004]

Smoke Alarm Article: NBC6
Interesting report. [Cedar Park, Oct 04 2004, last modified Oct 21 2004]

Very low power consumption wireless protocol for home security, safety and convenience uses; they anticipate a set of batteries lasting several years. [Cheradenine, Oct 04 2004, last modified Oct 21 2004]

Intelligent Smoke Alarm Technology http://www.halfbake...20and_20Egg_20Timer
Analyses smoke, selects appropriate alert mode. [egbert, Oct 04 2004, last modified Oct 05 2004]

(?) First Alert ONELINK® Wireless Smoke Detectors http://www.firstale...nelink_wireless.php
Looks like someone finally got around to baking this idea. [phoenix, Aug 04 2009]

//the same signal to automatically call the fire department//: I picture fire trucks arriving at my place every time I use the oven.

The [link] has an interesting report. Studies find that smoke detectors don't wake some kids. They're developing alert devices that play recordings of parent's voices, which apparently work much better. The networked part of this idea is apparently in the process of being baked.
-- Cedar Park, Jun 08 2003

[Cedar Park] My point. If the smoke alarm goes off upstairs - where the kids sleep - the parents my be completely unaware. Having all the alarms in the house trigger helps ensure someone will take notice.

[Shz] Thanks for the link. It seemed like too good an idea for me to have been the first to think of it. While the product in your link looks institutional rather than commerical and doesn't have the configurabilty I intend, I'll abide if a moderator marks this for deletion.
-- phoenix, Jun 08 2003

The only possible problem I can see with this idea is that, because the detectors would also have to include a transmitter and receiver, a standard 9V battery would not last a year. These systems would have to be hard-wired.
-- Cedar Park, Jun 09 2003

In the UK new builds must have a mains operated smoke alarm on every floor. There are provisions for battery back-up to be included. If there is more than one in the dwelling, they must be linked. A number of alarm companies provide for linking to the local fire service, however a lot of fire services will and do charge for false alarms.
-- oneoffdave, Jun 09 2003

prob: the fire alarms in adjacent houses along a terraced street would all go off in a mexican wave - like a line of dominoes. the fire brigade would not be sure which house was in trouble.
-- po, Jun 09 2003

There's a spec called "ZigBee" designed for this sort of thing; though it's been sitting around being not-implemented for a while now, it seems they're gradually making progress on it and expect to start launching products this year.
-- Cheradenine, Jun 09 2003

I think you could solve the problem mentioned by [po] and by a simple change that would have other beneficial effects. Instead of each alarm going off simply because it knows a nearby neighbor detected smoke, each alarm would go off only if 2 or more nearby alarms (possibly including itself) were actually detecting smoke.

You sell them in packs of 4 and tell people the warranty is void unless you install all of them spread out evenly in a single domicile, even a tiny one.

This solves two problems:

First, [po]s' scenario of the "mexican wave" cuts off right at your immediate neighbors, and goes no further, because the WiFi wouldn't reach farther than that. Homes attached or very close to the one with smoke in it would get warning, but it wouldn't go further unless those houses also got smoke.

Second, the incessant problem of smoke alarms going off because of simple burnt toast and the like is reduced. The smoke would have to reach two of the sensors before any of them would go off.
-- krelnik, Jun 09 2003

That's an interesting solution, but I hasten to add I included a variable range capability in my original spec. If you live in an apartment or condo, I don't think you'd mind being woken if your wallmate's flat is on fire.
-- phoenix, Jun 09 2003

//I don't think you'd mind being woken if your wallmate's flat is on fire//
I agree completely. The 2-or-more scheme allows that to happen, while not allowing the mexican wave to pass any further than the maximum transmission distance from the two sensors that are actually going off in your house.
-- krelnik, Jun 09 2003

//The smoke would have to reach two of the sensors before any of them would go off.// There slight problem with this is that ideally you'd want to be awake and start evacuation as soon as the smoke reaches the first alarm. Waiting for it to trip the second sensor could be fatal if the fire starts in the upper story of a 2 story building. A 'day' and 'night' setting might be the best compromise. 'Day' would require both to be tripped, 'night' only one.
-- oneoffdave, Jun 10 2003

[krelnik] But requires two or more detectors in the vicinity of the fire. By the time the smoke reached the second alarm, it might be too late. Alternately, if you're going to put smoke alarms close enought together to ensure they sense the same fire, why not just rely on one to begin with? We agree in prinicpal, if not in scope. [oneoffdave] has a good compromise.
-- phoenix, Jun 10 2003

Well perhaps I (and po?) were making an incorrect assumption about your original design.

I was assuming that if this alarm "heard" another one going off through WiFi, it would go off, whether or not either one of the two involved actually was the one who sensed the fire. I.e., if alarm A senses smoke, it goes off, and passes that to alarm B nearby. Now alarm B goes off (even though it doesn't sense smoke) and passes that to alarm C. Now alarm C goes off.....and so on. Hence the "mexican wave" scenario where the chain of buzzing alarms could far outpace the actual danger.

That was the problem I was trying to solve, but you tell me whether that was a poor assumption I was making.
-- krelnik, Jun 10 2003

Surely the whole point of an alarm is to allow you to outpace the actual danger? If I lived in a terrace, I'd be happy enough if my alarm warned me that the next door neighbour's house was on fire. Usually the whole row turns out into the road as soon as the Firemen arrive anyway.

I'd have to agree that being turfed out of bed at 1am due to the students next door over-grilling the pizza is not too endearing a prospect. Maybe my spectral analyzer technology would come in useful here? (see link).
-- egbert, Jun 10 2003

//whole point of an alarm is to allow you to outpace the actual danger?//
Well, there's outpace and there's outpace. If this weren't designed properly, and everyone in my area bought them, then that burned 1am pizza could potentially wake up not just your neighbors but the entire town.
-- krelnik, Jun 10 2003

Yes, I got that the first time. Hence the suggestion for spectral analyser technology.
-- egbert, Jun 10 2003

I hope that is carbonated ketchup with your eggy, eggy!
-- po, Jun 10 2003

[krelnik] My idea originally included a method for determining if a signal was from a "source" or a "repeater". It is an important aspect of the idea and I neglected to include it here. Thanks for pointing it out and sorry for the confusion.
-- phoenix, Jun 10 2003

Yeah, the other huge problem with my "two or more" scenario is human nature. Its hard enough to get people to buy even one smoke alarm for each floor, much less the two or three per room it would take for that to work. Some people would look at you like you were covered with ants if you suggested that.

However, if you combined the WiFi idea with your other idea about bundling a smoke alarm in other devices, it could work, because the alarms would be naturally ubiquitous. Just buy this particular brand of light bulb that has a smoke alarm built in.
-- krelnik, Jun 10 2003

How about a grill with a smoke detector that sends a temporary "stand down" signal to the other smoke alarms? It could incorporate a thermal trip to re-activate in case the grill does actually catch fire.
-- egbert, Jun 10 2003

Cool idea! I have a friend who just installed a range-top grill in his condo, that would buy that in a second. Everytime he grills meat, his smoke alarm (which is only about 10 feet away) goes nuts.
-- krelnik, Jun 10 2003

I just had this idea this weekend, not surprised I'm 6 years behind the curve. I think it's an excellent idea, and I'm adding a bun.
-- Noexit, Mar 09 2009

The 'Mexican Wave' smoke alarm would quickly cause every alarm in the city to go off. The fire service would then rush to the only house with no alarm sounding (because the alarm has melted in the inferno).
-- hippo, Aug 04 2009

It would be no big deal to "key" the alarms such that they only talk to the ones you want. This could range from every one in a highrise, to the two in a small house.
Either sell them in matched sets, plug in programmable at the store or simply have a program button that links units together if they are pressed within a 10 minute or so window (may be difficult in a large building, possibly have each successive press extend the window?) If you and your neighbors happened to be re-programming your smoke detectors at the same time, this might be a problem, but that isn't real likely.
The first pressed program button could also be set to detect surrounding signals and deliberately use a different code, minimizing the number of different codes actually required.
-- MechE, Aug 04 2009

Ganging your smoke alarms with the neighbours' sounds like a very good idea [+]
-- FlyingToaster, Aug 04 2009

Clever idea, but less fun than a wushu smoke alarm.
-- wagster, Aug 04 2009

This sounds like a great idea, but then your neighbor burns the toast at 4am.
-- MechE, Feb 09 2011

random, halfbakery