Carbon Monoxide poisoning

Jan 16, 2006 17 Replies

Carbon Monoxide poisoning



these alarms you can buy appear to hang from the ceiling as I understand it, carbon monoxide is heavier than air so surely would sit on the ground i.e. bit late if the gas reaches the ceiling am I barking mad or have a point here?


^^^^^^^^^^^^^^^^

Woof! (AFAIK)

"Vass" wrote

See:

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S

Where did you get that idea/

They are not intended to mount on the ceiling but on the wall near to the gas appliance.

sponix

must have lost my presence of mind... apols..

"Vass" typed

It's lighter than air and gases diffuse and mix fairly thoroughly anyway.

True, but only just. Molecular weights are:

CO = 12 + 16 = 28 N2 = 14 + 14 = 28 O2 = 16 + 16 = 32

Air is (effectively) 80% N2 and 20% O2, average molecular weight 28.9.

-- LSR

I suppose it must be...otherwise it wouldn't go up chimneys/flue pipes.

sponix

But won't all the nitrogen float to the top? LOL!!

Phil.

snipped-for-privacy@gmail.com wrote:

No - but for some reason your post has. Replies should be heavier than the quoted article.

-- LSR

I have read through the replies... um ... not a lot of light....

CO is very much the same density as air, obviously hot CO will convect upwards but essentially once mixed with air it stays mixed. The N2 and O2 components of air don't separate out by themselves and neither will CO.

CO is extremely toxic just 0.4% is fatal in minutes and even 0.1% can be fatal with a long exposure time.

CO is produced when fuels containing Carbon have insufficient air(oxygen) to properly burn. If any flame is yellow like a candle, be it from coal, coke, oil, gas, paper, wax, wood or garbage then soot (carbon) and CO are being produced.

There is really no reason to install a Carbon Monoxide detectors in the home, but there again there is no harm. You can get simple non-electronic orange spot cards "dark spot is danger" for much less cost and to much the same purpose.

Open flued and flueless gas appliances, and even an open fire grate all carry a CO poisoning risk. This risk can be brought to a safe level (i.e. where other aspects of life are much more risky) by

1) Never blocking any vents provided for gas appliances and open fires. 2) Having the gas appliance regularly checked.

The spot cards don't give an audible alarm. Unless you happen to notice them, they're of limited use. CO alarms will work if an appliance develops a fault or it's air supply becomes unexpectedly restricted by whatever means. They are also being used to detect fires I'm told. I would always favour a smoke alarm for this though. I have heard the detection ability of domestic CO alarms questioned. Of course the questioner was a sales person for a more sophisticated comercial variety but I do wonder how good the really cheap ones are especially when it's so difficult for a householder to test them. I agree that having gas appliances checked is always advisable but a CO alarm is a valuable second defence.

John

You are thinking of carbon dioxide, which is about 2.5 times heavier than air.

Colin Bignell

snipped-for-privacy@email.com (sPoNiX)typed

No, it's heat and convection that do that.

I suspect that in the large majority of cases where a domestic appliance produces dangerous amounts of CO it is as a result of prolonged and gradual deterioration, rather than sudden failure. In this situation the spot cards should be adequate.

Many US Cities now require CO alarms fitted in all domestic residences and not just new build.

If you have fossil fuel appliances installed it is prudent to fit a Kitemarked CO Alarm. There was even a case some years back where an all electric home had a CO event caused by chemical recation in storage heaters!

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