Carbon monoxide. Heating.

[Machpoint005]

And all that reduces false positives, and false negatives ... provided that you look at the display.

[mross]

For example, if your stove emits CO when kept in overnight when damped down and the weakened draw is less able to pull fumes up the chimney and the lower combustion temperature makes it more likely to produce higher quantities of noxious gas, you can see from the display that this is happening. Also, if you repeatedly get small releases of CO when, say, stoking the fire, these may not trigger an alarm but will show up on the display.

What sort of CO readings are you seeing? I would have thought any CO released would be diluted quickly as it ,a) disperses and is diluted by ventilation? CO does take some time to build up in the blood. Which make/model detector do you have? I've never seen any reading but zero when the door is closed.

[Sea Dog]

What sort of CO readings are you seeing? I would have thought any CO released would be diluted quickly as it ,a) disperses and is diluted by ventilation? CO does take some time to build up in the blood. Which make/model detector do you have? I've never seen any reading but zero when the door is closed.

I usually see 0ppm, but have seen the odd low figure recorded here and there. Something like 19ppm rings a bell, but I wouldn't swear to that. Most likely as a result of a bit of blowback with an open stove door? Of course, a leaky door seal or similar ought to be revealed by regular readings.

 

CO takes no time at all to build up in the blood - it's far more readily absorbed than oxygen and if that took some time to build up in the blood we'd all be dead! Once absorbed, it isn't readily released by haemoglobin like oxygen is. Herein lies the problem: we only have a limited supply of red blood cells which are replaced quite slowly. If a goodly number are effectively useless due to absorbing CO, the bloodstream can't deliver sufficient oxygen to the important organs.

 

I have the Fire Angel model someone provided a link to earlier. At home there's one near the gas boiler and one near the woodburner.

[mross]

I did some research and you are right that CO bonds to haemoglobin quickly. It is released slowly with a half-life of six to eight hours. Workplace safety regs limit exposure for an eight hour day to 50 ppm (35 ppm in USA). My point being that readings of this range won't harm you if they are of short duration. Obviously, when the fire's door is not open the reading should be zero or 1ppm (to allow for some sensor drift). Personally, I like to understand risk but not seek to eliminate all risk at expense of pleasure and relaxation. Some activities will double the risk of cancer (just as an example) but if the risk doubles from, say, one in a million to 2 in a million that's still a pretty small risk.

[NMEA]

That's true, of course. I don't think we need to satisfy anyone as regards CO alarms on our boats though, do we? Certainly not the BSS and my insurer doesn't ask for CO alarms either. Perhaps when alarms certified for use in boats are more readily available we will see them mandated, and I would welcome such a move. I can certainly see why a professional fitter would go the extra mile to fit an alarm to the marine standard though, and I would expect nothing less.

Your relatives or the relatives of people who die or become ill may again take a different view of an inappropriate or faulty device device, if it's aproved for use on boats there will be less of an issue. Its all about minimising risk and exposure in my view, but then again my risk and exposure is greater than most.

[mross]

The official advice, if you have a part 1 detector is to keep it, but get a part 2 device when you next renew it. So I think that gives you an 'out' in law.

[Sea Dog]

Your relatives or the relatives of people who die or become ill may again take a different view of an inappropriate or faulty device device, if it's aproved for use on boats there will be less of an issue. Its all about minimising risk and exposure in my view, but then again my risk and exposure is greater than most.

We're in danger of violently agreeing here! I concur entirely with your premis, tempered by (as mross points out above) the current advice that the non-marine one is acceptable at present but should be replaced in the fullness of time. Actually, there is no compunction to fit any CO alarm in our boats as far as I'm aware. My view is that the part 1 device I've selected is better than the best currently available part 2 device. When a better part 2 device is available I'd be delighted to change to it. Likewise, if I was in a seagoing vessel, I'd fit a part 2 monitor now.

 

I'm very familiar with risk assessment and, not having the onus of supplying to the public, I believe I have fitted the best devices available to me, the additional lcd display of any CO presence being a valuable addition to the binary Safe/Danger information provided a standard alarm. If I were fitting them as a business, however, I'd take the part 2 route every time for the very reasons you rightly identify. The difference lies between risk, with which I am satisfied, and exposure which, of course, the professional fitter must also mitigate.

 

If push came to shove for legal or insurance reasons (hence now exposure is in play) I'd supplement what I have with currently available part 2 devices until such times as the part 2 ones also monitor CO levels below the alarm threshold. I'm sure that's not far away anyway, which is why the advice allows for part 1s for the time being whilst the part 2 market catches up.

 

Perhaps we could do water mist extinguishers next!

 

In the meantime, everyone really should have good CO alarms in their boat.

[ditchcrawler]

 

 

If push came to shove for legal or insurance reasons (hence now exposure is in play) I'd supplement what I have with currently available part 2 devices until such times as the part 2 ones also monitor CO levels below the alarm threshold. I'm sure that's not far away anyway, which is why the advice allows for part 1s for the time being whilst the part 2 market catches up.

 

I think mine does but it and the paperwork are on the boat. As from a legal insurance point of view I don't believe it would be a problem as I don't fit them for others, I don't rent my boat out. As you say, on that basis if you had a fire the insurance company could turn round and refuse to pay because you hadn't fitted a water-mist to protect the boat, or if it was nicked you didn't have a tracker fitted.

[Naughty Cal]

http://www.ybw.com/news-from-yachting-boating-world/three-rescued-after-carbon-monoxide-leak-cardiff-yacht-club-44331

[ditchcrawler]

http://www.ybw.com/news-from-yachting-boating-world/three-rescued-after-carbon-monoxide-leak-cardiff-yacht-club-44331

I wonder what the source?

[fudd]

After reading this post, I thought I'd check my alarms. I have 2 fire angel co alarms. I opened my stove door and balanced them in the fumes. Apart from stinking my boat out, there was not even a squeak from either of them. One of them is brand new.

[WotEver]

After reading this post, I thought I'd check my alarms. I have 2 fire angel co alarms. I opened my stove door and balanced them in the fumes. Apart from stinking my boat out, there was not even a squeak from either of them. One of them is brand new.

Easiest way to check them is with an incense stick (what we used to call Joss sticks). If you don't have one, light a match and when it's fully alight blow it out and hold the smouldering end under the detector.

[Machpoint005]

After reading this post, I thought I'd check my alarms. I have 2 fire angel co alarms. I opened my stove door and balanced them in the fumes. Apart from stinking my boat out, there was not even a squeak from either of them. One of them is brand new.

 

As I understand it CO results from incomplete combustion, so this experiment may just be showing that the fire is burning its fuel properly.

Or that the CO is going up the flue just as it is supposed to?.

[fudd]

I'll try the joss stick approach.

Cheers. Steve P.

Tried it. Not a jot of anything.

Tried it. Not a jot of anything.

[mross]

Remember that at 300ppm it takes three minutes before the alarm is required to sound. Some CO detectors have a test mode that removes this time delay. Please, could you tell me the make and model and I will find out for you.

 

Edited to use figures from FireAngel

Edited November 15, 2016 by mross

[fudd]

Remember that at 300ppm it takes three minutes before the alarm is required to sound. Some CO detectors have a test mode that removes this time delay. Please, could you tell me the make and model and I will find out for you.

 

Edited to use figures from FireAngel

They are CO-9X-10s.

They sat in the smoke and fumes for 15 minutes.

[mross]

Here is the manual. There is a special test mode on this unit. See 'annual sensor testing'. I think you will find this test will give you confidence that it is working properly.

[fudd]

Thank you. I will test them when I'm on the boat next.

Steve P

[mross]

Please update here when you have tested them, thanks.

[fudd]

Will do.