I have a summer place with a ventless gas stove/heater . Rub it for very long and the humidity rises and anyone with sinus or breathing issues starts to feel in comfortable . We will use it the morning for 20 minutes or so to the chill off and sometimes decoratively at night for 30 to 46 minutes but we always open a window. If I retire there it will get replaced with a vented unit first thing . I vote no from experience.