The byproduct of burning mercaptan is sulfur dioxide which smells more like burnt matches mixed with rotten eggs.
Vent free gas log odor.
This is a physical property which cannot be eliminated but can be diluted.
A vent free appliance requires room air to operate.
The burning of gas produces a natural odor of combustion.
Allow the gas logs to cure.
Vent free gas log odors.
A stale air smell can be created when airborne particulate is drawn into the gas log set as it operates see how to clean the unit below.
Vent free gas log will not produce an odor unless the air it takes in has an odor.
Rasmussen does not use paint based coloration as the paint can burn away and cause odors which is especially noticeable in vent free sets.
Include other odors produced by impurities in the gas supply and you have the distinct smell ventless logs produce.
In reality the cause of these odors is airborne contaminants.
Some people who purchase vent free gas logs complain of an odor that occurs while burning the appliance.
When the room air gets mixed with dirty air it can smell like a petroleum based product.
This time period is called curing and it causes an unavoidable odor.
People worry that this is due to poor air quality in the room due to the lack of ventilation.
Rasmussen uses inert ceramic stain mixtures which do not create any odor when burned.
According to magic sweep corporation when a newly installed unit first is turned on there will be an odor for approximately four to eight hours if the vent free fireplace has gas logs.
If you think the odor could possibly be coming from an airborne odor eliminate what you think is causing the odor and let the air settle for a hour or so and try burning the log set again.
After about eight hours the smell should stop.