I assume when the fireplace industry named them “Vent-Free” the move was to play upon the term “free”.
I’d like to offer you this opportunity to watch a short video (with Quiz) and to read this article by Dr Allison Bailes. I often quote Dr Bailes here on Real Estate Reality and do so again:
Yeah, they may have fancy technology built into them now (oxygen depletion sensors and catalytic converters), but the bottom line is that the risks can outweigh the benefits. It’s not that hard to build a chase and cut a hole to install a direct vent model, so why take that risk?