Ventless Gas Logs release heat (and moisture) into the same room where the vent-free fireplace is installed and recirculate the same air back into the room. Vented Gas Logs burn similar to real wood and need a chimney vent pipe that allows air to escape outside the home rather than back into the room.

How do non Vented gas logs work?

The ventless fireplace works in a U-shaped path. Oxygen is taken in from the room and typically enters through the bottom of the fireplace. The regulator mixes the air with gas to produce the fire. There's usually a vent at the top that releases air back into the room.

Do ventless gas fireplaces give off carbon monoxide?

Ventless fireplaces produce small amounts of nitrous dioxide and carbon monoxide which can be deadly in large doses. ... In addition to carbon monoxide, ventless fireplaces also produce a high levels of water vapor. The increased level of water vapor in the home will increase humidity, increasing the risk of mold growth.