Carbon Monoxide alarms

[jakespop]

When recommending Part 1 and part 6 systems, are there combined CO and Smoke alarms available and recommended? A recent case locally has raised concern especially in bed sits and similar.

[AnthonyB]

Kidde have produced dual smoke/CO alarms for a while, but the one's I last saw were single station battery only ones, no dual supply or link facility.

[colin todd]

You can get co/smoke multi sensors

[kurnal]

I may have misread the original posting but I took the posting to be about the potential for combining both life safety detection of CO and detection of fire within a single detector. I think we will all agree that multi sensor heads as part of a fire alarm and detection system should only be used for the detection of fire.

Are the parameters for a CO (life Safety) detector the same as those for a  CO (combustion gas) fire detector? I was under the impression that the alarm thresholds for each purpose were  very different but would be pleased to be corrected.

The life span of a life safety CO detector is generally a maximum of 7 years according to most manufacturers. The typical life span of a smoke fire detector is 10 years.

If the two purposes  were combined in a single head presumably the whole thing would need to be replaced at 7 years, which if part of a large system could be a significant cost burden. It would also need to give a very differnt alarm signal to differentiate between the two purposes.

Although programmable, I believe the default for most systems with multi sensor heads would be to give just a pre alarm in the presence of CO only. Sorry if I have gone off at a tangent and the only reason for the OP was the control of unwanted signals.

[jakespop]

Thanks Kurnal. Yes the original posting was enquiring about possibility of combining in one detector. It seems more satisfactory to have a single stand alone CO detector as well as smoke/heat detectors from what you say and which is what I suspected. Thanks.

[SamFIRT]

As a matter of interest what are the threshold limits for activation of a life risk CO detector as opposed to CO detectors used to raise awareness of fire? Anyone know?

[kurnal]

From what I can glean on the web,

The European Standard for carbon monoxide alarms  EN50291
 
Main alarm requirements:
 
1- at 30ppm CO, the alarm must not activate for at least 120 minutes
2- at 50ppm CO, the alarm must not activate before 60 minutes but must activate before 90 minutes
3- at 100ppm CO, the alarm must not activate before 10 minutes but must activate before 40 minutes
4- at 300ppm CO, the alarm must activate within 3 minutes


Whereas a typical CO fire detector alerts at 40ppm. Source http://www.tycoemea.com/english/pdf/datasht/fire/PSF094A.pdf
 

[Midland Retty]

As many have already said combined CO/Smoke detectors are available on the market, and have been for a while.

Their sole purpose is to detect fire, they are not designed to warn of possible carbon monxide poisoning.

A Carbon Monoxide (Fire) detector should not be mixed up with a Carbon Monoxide Alarm (which alerts people to carbon monide poisoning)

[AnthonyB]

Yes, I agree they are different beasts - however I misread the original question and thought it related not to CO fire detectors, but CO life safety detectors.

The Kidde unit I referred to is a domestic use device that has an ion smoke chamber for fire and a CO detector for life safety against CO poisoning from gas appliances in the one unit and uses voice alarms as well as different tones to identify the different warnings

[Gel]

For info this product type can gain UL Approval for a combined smoke & CO alarm, but
in UK there is a conflict with IP ratings so that one combi alarm cannot achieve BS Kitemarking
to the smoke EN 14604 and CO EN 50291 Standards.

There has been a frustration on this for some years, but there may be some movement in short term to
remove the IP rating from battery CO alarms; in US they also have hard wired variants too.

In a fire situation, the alarm will always give priority to the danger of fire; Kidde's has advantage
of being only UK one where there is a voice warning so resident totally clear as to what danger has
set off alarm.
Some FRS have used these for boat safety initiatives.