Carbon monoxide from wood burning fireplace open/closed?

[Jotel me this]

I have a Xtrordinair 44 fireplace that has to be operated with the doors shut. The manual says to check the gaskets to ensure a good seal (better burn) but also to minimize CO poisonings. Question is..

Ive lived my whole life with an old school wood burning fireplace that uses just a screen to protect from sparks. Open flames burning away, throw logs on, and enjoy the night.

If a completely open fireplace is ok and safe... which produces CO.. which has no protection against CO from entering the house, why do certain fireplaces have to be shut to protect against CO poisoning?

 

[bholler]

I have a Xtrordinair 44 fireplace that has to be operated with the doors shut. The manual says to check the gaskets to ensure a good seal (better burn) but also to minimize CO poisonings. Question is..

Ive lived my whole life with an old school wood burning fireplace that uses just a screen to protect from sparks. Open flames burning away, throw logs on, and enjoy the night.

If a completely open fireplace is ok and safe... which produces CO.. which has no protection against CO from entering the house, why do certain fireplaces have to be shut to protect against CO poisoning?

Because their flue is much smaller to make them work efficiently. That means with the doors open that flue won't be able to properly exhaust everything.

Co can also be a problem with open fireplaces if draft stalls at the end of a fire, if there isn't adequate makeup air, or it is poorly constructed.