Pete,
The inverter paraffin heaters I mention don't put out water vapour and only give off a slight wiff for a minute when lighting and extinguishing.  Any heater (gas, paraffin or log) will use oxygen from the room.  It's needed for combustion so some form of ventilation is required.
Log fires with back boilers can be used for a form of central heating but the general opinion is that "cheap" log burners (with or without back boiler) are a waste of money.