I've searched through the sub and read the previous posts but they're several years old and locked for responses.

I'm looking at converting out existing wood burning fireplace (which drafts poorly) to a gas insert and debating the direct vent vs ventless options. The ventless is a lot cheaper and much more efficient which is why I'm considering it. I've read plenty of articles debating both sides of the health issues related to CO but I'm looking for opinions from people who actually own and use their ventless fireplaces.

I'm aware of the potential CO issues and moisture that these things create but I'm just trying to get a feel for how serious they would be for our home.

We have a 1960s era 2 story house, which is hardly air tight and the existing fireplace is in our great room which is open to the kitchen. Total square footage for the combined rooms is ~500sqft. I'd be looking at a 25k BTU unit which would only be used occasionally and not as a primary heat source. How much of a concern is the CO in a room that size? Should I be concerned running this thing for a couple hours once a week or so?

Some factors we have that may help mitigate the CO isssue: We have a gas range in the same room with a 900 CFM hood installed and properly vented to the outside. If the CO detectors were to ever go off we could clear the room pretty quickly. We also have a brand new 96% efficient furnace with variable blower that runs on low 95% of the time to circulate air. I'm not concerned with the moisture aspect because we're in Ohio and our house is typically very dry in winter. Humidity in the house is around ~20% if we don't use the humidifier. I'm actually thinking the ventless fireplace could help here.

Who has one of these? Am I crazy to have one installed instead of spending the extra money for the direct vent?