What is the source of CO when using things like BBQs?

I am wondering because I don’t understand why my woodburner doesn’t kill me, but there are horror stories of people – both stupid and not-so-stupid – being killed by emissions from BBQs used (or allowed to cool down) indoors.

Furthermore, I grew up with a ‘JennAir’ cooker in my house, which had a grill on one side of it. Would that not have produced carbon monoxide in quantities enough to kill?

What is the difference between all these fire-based sources of heat?

I don’t understand why my woodburner doesn’t kill me,

I assume you have attached a flue to your woodburner which allows the products of combustion to leave the house?

and a sufficient supply of fresh air, hence stoves over 5 kW requiring a vent to outside to be installed.

Carbon Monoxide is produced when things burn in enclosed spaces where oxygen is limited. Your stove will produce CO but as above will be vented through the flue.

Okay, I get that bit, but what about the cooker I mentioned?

Ours looked similar to this:

with the BBQ-type grill on one side. Of course, there was a fan in the middle, but we didn’t always turn it on, and what’s more, it visibly did not capture all the fumes in any case.

Also, there was a tragic story of a man who went camping with his girlfriend, and brought what he thought was the already-cool BBQ inside the tent as it was starting to rain.

In any case it killed his partner and almost killed him.

So I assume it is the heat and not the flame per se. Would I be right?

But if that’s the case, is the solution just venting? Because presumably you can’t vent heat. And wouldn’t a BBQ cool enough to touch have expended enough heat that it wouldn’t need venting?

And wouldn’t a BBQ cool enough to touch have expended enough heat that it wouldn’t need venting?

The story preceding this part of your post implies not…

It’s incomplete combustion where there’s insufficient oxygen – if there’s enough oxygen atoms for the carbon ones it will grab two each(carbon dioxide) – if not it will have to make do with one each (monoxide). so it’s neither the flame nor the heat as such that CAUSE the problem.

Although flames can give you a clue (reflecting incomplete combustion) – remember Bunsen burners at school? wee collar at the bottom closed so no air getting in: orange flame. Collar open and air getting in: hotter, fiercer blue flame.

Incomplete combustion.

With a good air supply, combustion should be complete and you end up with C02, without enough air (oxygen) for the fuel to combust properly, you end up with C0 – i.e. half as much oxygen in the resulting gas molecules.

Your woodburner can and will produce C0 and potentially kill you, particularly if you shut it right down and let it burn slowly, as this results in incomplete combustion.

Having a suitable air supply (i.e. draughty room or vent brick for over 5kW), as stated above, a well ventilated room/property, and a well sealed stove and flue can prevent it though. Best advice really is not to shut stoves down too much.

Since 2010 it has been a legal requirement of The Building Regulations to install a C0 detector in the same room as any new woodburner. That should help warn you………

Flameless combustion is possible. Flames are a side effect of combustion

Ah! Starting to understand now…

Flameless combustion is possible. Flames are a side effect of combustion

aren’t flames caused by gasses combusting as they rise?

(hence why pure carbon just glows)

Flames are just visible gasses are particles resulting from the combustion. The reaction can take place without visible flames, within cooling lumps of charcoal for example.