Just like wood vented gas logs produce co carbon monoxide emissions.
Vented versus unvented gas logs.
If you re looking to add a supplemental efficient heat source to your home you may want to go with a vent free gas log set.
Vented gas fireplaces are not as flexible as ventless gas fireplaces in order to install a vented gas fireplace you must use a chimney or an exterior wall.
They put out a constant rate of heat.
Vented gas logs offer the most realistic flame.
The fire wraps around the logs like they would in a real wood fire and the yellow flames are generally taller than those in ventless sets which adds to the realism.
Unlike vented these logs do not require a chimney or flue to operate allowing more heat to stay in your home.
Vented gas logs are ideal if you value ambience over efficiency or if you have an existing wood burning fireplace that you want to convert to gas.
This is so that it can both take in air from the outside and then vent out the by products from the flames inside the fire box.