direct vented vs vent free

benefits (other than the cost) for a vent free propane heater (rinnai) vs a direct vented heater?

what are we talking about...gas logs?

What kind of heater?

If you are talking about water heaters ( Rinnai?) you will have to explain "vent free" because I have not seen anything you can run without a vent/

There are gas space heaters that are called "vent-free", but I would not have one. Their exhaust is not good for breathing, and they consume oxygen that is. In my own opinion, free-standing and/or non-vented heaters burning *any* kind of fuel simply do not belong in the house.