Smoke Alarm

[spiidey]

We have two "Dicon 670MBX Ionization Type Smoke Alarms" in our house.

We were replacing the battery in one of them and noticed the following wording on the inside of the alarm:-

"Date of Manufacture Apr 15, 2005
Date of Replacement Apr 15, 2015"

What does "replacement" mean - the entire alarm fitting? Is this standard practice - for an alarm to be replaced every 10 years?

 

[bernardgreen]

Yes it is replacement of the whole device. The ionising source, a radioactive material, decays with time and the sensitivity of the sensor reduces as the amount of radio-activity reduces.

The amount and type of radiation that gets out of the sensor is harmless even when new.

 

[spiidey]

Yes it is replacement of the whole device. The ionising source, a radioactive material, decays with time and the sensitivity of the sensor reduces as the amount of radio-activity reduces.

The amount and type of radiation that gets out of the sensor is harmless even when new.

Thank you.

So how difficult is the change over?

Is the following product suitable for a direct change over:-

http://m.screwfix.com/p/brk-670mbx-...4LVJskrJH9SVMFUragNfr7RjVMUaaQYcYihoC4Xfw_wcB

And if so, is it simply a case of taking the plug with the blue/brown cables out of the existing alarm and plugging this into the replacement alarm?

Or is it far more technical?

 

[PrenticeBoyofDerry]

Where are these alarms located? as Ionization Smokes are often located in the wrong areas of properties.
And if replacing you maybe best suited with optical ones.

 

[spiidey]

Where are these alarms located? as Ionization Smokes are often located in the wrong areas of properties.
And if replacing you maybe best suited with optical ones.

Two smokes:-

One in hallway downstairs (hallway in middle of lounge (left hand side) and family room (right hand side).

Second smoke in landing upstairs.

Plans in linked schedule (to identical house in terms of layout).

http://www.gsbproperties.co.uk/pdf/LaidlawGardens20086.pdf

 

[PrenticeBoyofDerry]

They should be both optical smoke alarms then.

http://www.aico.co.uk/What-works-where.html

 

[JohnW2]

They should be both optical smoke alarms then. http://www.aico.co.uk/What-works-where.html[/QUOTE]
I see that they don't recommend ionisation detectors in most locations (which may well be fair enough), except, as an option, in bedrooms. I have to say that rather surprises me - what do you think?

Kind Regards, John

 

[ban-all-sheds]

The amount and type of radiation that gets out of the sensor is harmless even when new.

Depends on how many you can get hold of.

http://en.wikipedia.org/wiki/David_Hahn

 

[bernardgreen]

Ah yes, the ultimate in DIY alternate home energy production. Thank you BAS.
From click here

Americium dioxide, AmO2, was first offered for sale by the US Atomic Energy Commission in 1962 and the price of US$1500 per gram has remained virtually unchanged since. One gram of americium oxide provides enough active material for more than three million household smoke detectors.

More useful information about radio active smoke alarms can be found here

http://www.llrc.org/smokedetect/smokedetectpage.htm

Other sources ( information and radiation ) are available.

 

[PrenticeBoyofDerry]

I see that they don't recommend ionisation detectors in most locations, except as an option, in bedrooms. I have to say that rather surprises me - what do you think?

I think, I am surprised that you are surprised!

I would personally fit multi-sensors in bedrooms.

 

[JohnW2]

I see that they don't recommend ionisation detectors in most locations, except as an option, in bedrooms. I have to say that rather surprises me - what do you think?

I think, I am surprised that you are surprised!

Maybe you have misunderstood the reason why I am surprised....

I would personally fit multi-sensors in bedrooms.

So probably would I - i.e. taken with the other recommendations, that would mean that I wouldn't use ionisation detectors anywhere. However, if I were forced to single out one type of room in which I felt that ionisation detectors might be an acceptable alternative to multi-sensor ones, I don't think it would be bedrooms. That's what surprised me - but maybe I'm missing the logic in that.

Kind Regards, John

 

[PrenticeBoyofDerry]

The fact that Ionization alarms react best to rapid fires, rather than smouldering fires. Would lead me to think, that having those in an area where you sleep, would be a fair option.

 

[JohnW2]

The fact that Ionization alarms react best to rapid fires, rather than smouldering fires. Would lead me to think, that having those in an area where you sleep, would be a fair option.

Well, my surprise resulted from the fact that I don't think that I would think like that. AFAIAA, most fires do not start in bedrooms, and most people who 'die in their sleep' as a result of fires do so because of smoke entering the bedroom from elsewhere (more like a 'smouldering fire', I would have thought) rather than because of a 'blazing fire' actually in the bedroom. However, maybe my assumptions and/or reasoning, are wrong.

Kind Regards, John

 

[PrenticeBoyofDerry]

Well in that case, a smouldering fire would have already been detected by the opticals in hall/landing.

 

[JohnW2]

Well in that case, a smouldering fire would have already been detected by the opticals in hall/landing.

True. I suspect the truth is that it doesn't make much difference, but I would (like you) personally be more inclined to put an optical (or multi) in the bedrooms (if they had sensors), as well as everywhere else (apart from kitchen).

Kind Regards, John