What you should know before you buy vent-free gas logs. A ventless appliance of any kind will have an efficiency rating of 99.9% because they burn so clean. A vent-free gas log is fairly simple in the way they work. By deliberately mixing the gas going into the burner with oxygen from the room will create a complete combustion therefore resulting in an efficient clean burn. This technology dates back to 1980 when the first vent-free space heaters were injected. Since then manufactures have rolled this into gas logs, fireplaces and even fire pits with safety in mind all vent-free appliances are equipped with an ODS (oxygen depletion sensor) that will automatically turn the gas off if the pilot light does not since adequate oxygen in the air for the appliance to burn properly.
Being in the Hearth, Patio and Barbecue business for over 20 years I have sold thousands of vent-free gas logs and fireplaces and the largest complaint I get is that they are putting out too much heat and that the customer can only use their gas fire logs for a few hours before they run them out of the room. This is why you need to consult a professional before purchasing you gas fire logs and let them size the set for your room size. Going to the big box store and asking who ever in standing closest to the fireplace section does not count ask asking a professional about installing your gas log. Some customer complain about their vent-free logs putting off an odor and that goes back to burning clean. The only way a vent-free gas fire log will put off an odor is if they air in the room that it is breathing has an airborne odor such as household cleaning products, air fresheners or anything with an odor. If you remember that unit requires oxygen from the room air to burn clean and when the burner is consuming that room air with the airborne odor it will take that odor into the burner with the oxygen and burn that odor with the oxygen creating a foul odor that smells like kerosene to me.
Something else you should know if you own a vent-free gas log is about complete and incomplete combustion. A complete combustion is when the gas log is getting the proper gas and air mixture and the flames from the burner are not impinging upon the log sitting on top of the burner. An Incomplete combustion is when the burner is not getting the proper gas and air mixture due to clogged air intake or improper size gas line running to the gas log. And the most common incomplete combustion is when a log on top of the burner is misplaced and coming in contact with the flame. This will cause the incomplete combustion and with that will cause the gas log to soot. Make sure none of the logs are coming in contact with the flame and that they are all positioned as shown in the owner's manual to be safe.
A few simple things to look for when buying gas logs is to ask about the warranty. Make sure the warranty covers parts and labor for at least 3 years if not more. All of the fire logs we sell will last 10 plus years because they made in the USA with quality parts and tested before they leave the manufacture. You will also have a choice of control options such as manual control, remote ready and electronic ignition. The manual control means just that, you have one know that you turn from low, medium and high. Remote ready means that you can add a remote or wall switch but the unit does not come with one. With a remote ready you can add a simple on / off remote or a thermostat remote that will turn the log on and off at the temperature you have it set at. The newest trend in gas logs is the electronic ignition, this control will allow you to light the pilot light from the remote and also adjust the flame height from the remote. Also know that gas logs are made from ceramic refractory or ceramic fiber. The ceramic refractory is concrete based and the ceramic fiber is fiber based light weight. They both have their advantage because the fiber log set do not expand and contract due to heat and most of them have a little better detail. I like the concrete logs because the hold heat when you turn the burner off and they do not absorb household odors like the fiber logs. You can also wash a concrete log and you can not a fiber log.