SteveAE wrote:
...For fear of starting the vented vs. non-vented debate...here is my answer.
Here's the short version of the debate:
"I've run my unvented combustion heater for years, with a window cracked and lived to post about it"
vs.
"It makes CO2 and CO and people have died from using them incorrectly" (And that's why "just crack a window" isn't good enough for the directions).
Both are correct.
There seems to be a lot of strong opinions on the topic, and I expect this short summary will not satisfy those with the strong opinions.
I would consider what the consequences are of dismissing either of the two sides of the argument.
