Carbon Monoxide?

[TonyBuckley]

Where is the best place for an alarm to go? I have one (portable) and move it around depending what I am doing.

Is it best up high, or low down, or doesn't it matter.

Dangled just below my nostrils seems the ideal place.

 

[charles_reed]

Probably resulting from the recent tragedy of a couple who died in a narrowboat,

However, on that occasion, it was a solid-fuel heater.

Quite a common incident:-
http://www.lancashiretelegraph.co.u..._monoxide_alarms_after_tragedy_on_narrowboat/

If one really wants to be morbid http://www.co-gassafety.co.uk/deaths.html
Statistically very infrequent for boaters, so on a par with death by lightning strike in the UK.

 

[coopec]

Dangers of portable gas heaters
in a confined space

Extreme caution should be used when thinking of using a gas, dual fuel, a kerosene heater, heat beads or even a stove for that matter inside an enclosed area such as a tent, camper trailer or caravan to keep warm on a cold night camping. Please make sure you have all windows open so the fumes will not build up.

Carbon monoxide is a colourless and odourless gas, slightly lighter than air. It is formed whenever any carbon-based substance, which is most substances, is burned with an inadequate supply of air. Even when there is adequate air, carbon monoxide is produced if the burning reaction is only partly complete. Burning anything in a small enclosed space presents two main dangers.

The first and most serious is carbon monoxide poisoning. Even in small amounts, carbon monoxide is deadly to all warm-blooded animals. A 0.2% concentration can kill within 30 minutes. Carbon monoxide kills like this. Haemoglobin in the blood normally transports all-essential oxygen throughout the body. Unfortunately haemoglobin is massively addicted to picking up carbon monoxide. If there's any around, haemoglobin will grab 250 parts of carbon monoxide for every one part of oxygen. This rapidly deprives the brain and everything else of that vital oxygen. There are only minor indications: headache, nausea, fatigue and then unconsciousness. If you were asleep at the time, the odds are against your ever waking up again. Carbon monoxide is rightly called the 'silent killer'.

The second hazard is direct oxygen deprivation. Just by breathing we contaminate the air. We take in about a half a cubic metre of air every hour and convert about 4% of that into carbon dioxide. As a result the exhaled carbon dioxide level rises and the available oxygen level falls. The latter can however drop from its normal 21% or so, to as low as 15% before symptoms such as fatigue set in. Oxygen deprivation through this cause can be serious in an unventilated space – heated or otherwise.

 

[sailorman]

Where is the best place for an alarm to go? I have one (portable) and move it around depending what I am doing.

Is it best up high, or low down, or doesn't it matter.

Dangled just below my nostrils seems the ideal place.

on a bulkhead just down about 150m/m from the deckhead

 

[coopec]

on a bulkhead just down about 150m/m from the deckhead

Sailorman

That makes sense as carbon monoxide is slightly less dense than air so presumably it would collect about the deck. Just something I found out while researching my question is that you must install smoke alarms AND CO alarms.

My Question. The LPG gas we use in Australia is heavier than air so the gas alarm has to go down in the bilge adjacent to the gas stove?

 

[Colvic Watson]

on a bulkhead just down about 150m/m from the deckhead

Leaflet with mine said not to put it that close to the ceiling. It's a dead space in convection currents where the air doesn't change much so less chance of detection.

 

[Giblets]

Normal positioning is about 1500 above floor level.

 

[coopec]

QUOTE Installation locations vary by manufacturer. Manufacturers' recommendations differ to a certain degree based on research conducted with each one's specific detector. Therefore, make sure to read the provided installation manual for each detector before installing.

CO detectors do not serve as smoke detectors and vice versa. However, dual smoke/CO detectors are also sold. Smoke detectors detect the smoke generated by flaming or smoldering fires, whereas CO detectors can alarm people about faulty fuel burning devices to prevent carbon monoxide poisoning. Carbon monoxide is produced from incomplete combustion of fossil fuels. In the home CO can be formed, for example, by open flames, space heaters, water heaters, blocked chimneys or running a car inside a garage.UNQUOTE

 

[Poignard]

Out of interest the worst section of the cooker for producing CO is normally the grille.

Why is that?

 

[prv]

My Question. The LPG gas we use in Australia is heavier than air so the gas alarm has to go down in the bilge adjacent to the gas stove?

That's correct, for an alarm meant to detect leaking LPG. Not to be confused with an alarm for detecting carbon monoxide, or a smoke alarm. I suppose to be thorough, one ought to have all three. Our boat has LPG and CO alarms, but not smoke.

Pete

 

[caiman]

There was a family killed whilst on their boat in the Lake District last year.Two young men died aboard their fishing boat in Whitby this year.Both incidents are suspected/confirmed Carbon Monoxide poisening and are being investigated over on the MAIB site where they have published a 'flyer' showing a badly burning grill.Well worth a read.Prehaps someone could post a 'link' ?
Cheers

 

[Giblets]

Why is that?

The majority of grilles on leisure/marine cookers (and some domestic ones as well) work by the flames impinging on an expanded metal fret of some type which then heats up and thus does the "grilling". This fret can quite easily become distorted or damaged without being noticed and thereby affect the flame picture/configuration leading to incorrect combustion and the production of very high CO ppm. I have tested both leisure and domestic grilles for CO over the years and have quite regularly had readings well in excess of 500ppm CO.

 

[AntarcticPilot]

Worth noting that paraffin pressure stoves are much worse at producing CO (in-house tests done where I used to work; sadly not published). Even a well-adjusted, properly burning paraffin stove produces CO in safe but worrying amounts - even putting a pan full of ice over the flame can cause excessive CO production if the pan is too close to the flame. A badly adjusted one can be and has been utterly lethal. Propane and Butane are much safer in that respect.

 

[TonyBuckley]

My hob burns very yellow. Grill is safe as it doesn't work at all lol.

I need to find a way to clean the hob jets and get it back to nice and blue!

Window leak above the hob does not help!

 

[BSSOffice]

...even putting a pan full of ice over the flame can cause excessive CO production if the pan is too close to the flame. A badly adjusted one can be and has been utterly lethal. Propane and Butane are much safer in that respect.

LPG stoves are also affected by heat being removed from the combustion process and can quickly produce 400ppm - the alarm triggering territory - but this is usually brief. [Reducing the heat in the flame reduces the combustion efficiency.]

The trick is not to put too large - too full pot of cold contents (potatoes to boil) on the stove, nor to leave it unattended. Having good ventilation is already mentioned also key.

Some people have asked about placing alarms - this is what the CO alarm manufacturers association advises http://www.boatsafetyscheme.org/stay-safe/carbon-monoxide-%28co%29/placing-co-alarms/

And somebody mentioned the number of deaths - that is over 30 on boats in the past twenty years. [depending on inquests - Five in the past year]

See also http://www.maib.gov.uk/publications/safety_bulletins/safety_bulletins_2014/safety_bulletin_1_2014.cfm and
http://www.maib.gov.uk/publications/safety_bulletins/safety_bulletin_2013/safety_bulletin_2_2013.cfm

 

[Seajet]

I got my Co alarm thru Amazon,they have a selection and as always good value.

Kidde 7DCO CO alarm 10 year guarantee, LCD display of level, audio alarm & light, with Duracell batteries about £20.

 

[Poignard]

The majority of grilles etc

Thanks Giblets, I never knew that.

 

[Andrew G]

Isn't CO from a leaky engine/exhaust a more frequent cause? Andrew (Brut has CO, gas and smoke detectors)

 

[nigelmercier]

I even bought one for home: http://amzn.to/1il5ZIB

I got my Co alarm thru Amazon,they have a selection and as always good value.
Kidde 7DCO CO alarm 10 year guarantee, LCD display of level, audio alarm & light, with Duracell batteries about £20.

This, as above: http://amzn.to/1il5ZIB

 

[Sandy]

Normal positioning is about 1500 above floor level.

How high is your bunk?