Ventless gas fireplace logs with ceramic gas logs and alternative fires.

What is a vent-less gas log?

birch log gas fireplace, vent free installation for ventless gas fireplace logs

Basically, when you shop outside for gas logs, you’ll find there are two major types. Vented gas fireplaces vent to outside like a wood burning fire place while ventless gas fireplaces will burn with little or no ventilation. Burning gas or wood produce few dangerous lethal compounds like carbon dioxide which is obviously harmful to the green earth and carbon monoxide which is dangerous to carbon-based life forms (you and me!). Vent-less gas logs are designed to produce a hot flame that results in nearly complete fuel combustion through which the release of carbon dioxide, carbon monoxide and other results of burning gas is decreased to a safe amount.


Generally ventless gas fireplace logs are equipped with oxygen depletion Sensors (ODS) which function to turn the gas off when the carbon monoxide increases to a threat level in the room.  In addition to ODS vent gas fireplaces also use a fixed position for logs, shapes, glass, fire balls and anything else in the fireplace.  By minimizing the space where flames touch solid objects, carbon is not created by the burning gas.  To help with the lowered carbon output the BTU is rated below 40,000 BTU for unvented gas fireplaces.  A thermocouple holds the gas valve open when it is hot so that if the flames or the pilot go out the gas valve closes and there is never an opportunity for a gas leak.


The ventless gas fireplace logs can be installed in a masonry fire place but generally the easiest and safest way to install a unvented gas fireplace is with a vent-free firebox.  With a vent-free firebox the gas burning flames and heat are contained and insulated within the ventless box.  The inside of the box is lined with refractive stone like a masonry fireplace but they are also available lined in a flat black and in stainless steel.  The bulk of the fire box is insulation and the insulation contains the eat so wood, dry wall or any other combustible material can be used to build a mantle or decorate the area around the fireplace.


A major benefit to opt a vent less gas log is that it does not cost a lot. These gas logs are more functional and easier to install, to use and to clean than traditional fireplaces. Many homeowners who have been through a storm and have damage to a chimney flue will experience the “sticker-shock” at the tremendous expense of repairing or replacing a flue.  A vented gas log fireplace burner needs the same chimney flue as a wood burning fireplace so for this situation an unvented gas fireplace kit is the perfect solution.  Ventless gas logs are not expensive and installation is as simple as hooking up the gas line.

unvented gas fire glass fireplace with blue glass and stainless vent free burner

stainless steel ventless gas fireplace with blue fire glass

Gas fireplaces use a control valve to control the flow of gas and the amount of flames burning through the fireplace burner and displaying through the logs.  Some ventless fireplace burners are designed for glowing embers over tall flames, some designed for taller flame and many burners combine the two styles with both raised flames and a smaller slope burner up front for beautiful displays of color among burning embers.  Because the unvented gas fireplace burner is legally limited to forty-thousand BTU’s the larger the burner, the less display is possible for the flames.  Most unvented burners look best at an eighteen to twenty-four inch width.  The control valves can be manual and work just like the ignition and valve on a barbecue grill but valves are also available that use a remote receiver and transmitter for on-off control, variable flame adjustment and as a wall switch or wall-mounted thermostatic control that turns the fireplace on and off dependent on the temperature in the room.

fire shapes burning in vent free gas log fireplace

ventless gas fire shape fireplace

Ventless gas log fireplace kits used to be used only in situations where a flue was damaged beyond affordable repair or when a fireplace could not be installed with a chimney because of building codes and local laws.  In the past few years fireplace manufacturers have placed a lot of research and development funds into ventless gas fireplaces  Ceramic logs used to be just “logs” that came with the burner, valve and box but today the logs are hand-painted to mimic real wood with startling clarity.  Placed side by side with actual wood logs the steel-reinforced ceramic logs look more real then the real wood logs.  Moreover, alternatives to ceramic logs are flourishing.  Ventless gas fireplaces use fire balls that look like cannon balls with long tongues of flame licking through the stack, geo-metric fire shapes, river rocks and highly reflective crushed glass and even stainless steel and black pan burners with no media that display ribbons of fire.  These modern fireplaces have a stark contemporary decor without the cold emptiness of typically contemporary home design.  Ventless gas fireplaces are no longer something homeowners settle for but a beautiful design sought out for its awesome beauty.