The brightest, most realistic flames are those dancing around vented gas logs. These gas logs are made for a fireplace with an open chimney flue so that more combustible air churns inside and fuels a bright, yellow flame. The downside to realism is that vented gas logs can use up to 90,000 BTUs (British Thermal Units) per hour creating that gorgeous flame, but only a small percentage of that is radiated to heat your living space—the rest escapes through the chimney’s open flue.
Hands down, the honors for the most efficient blaze go to vent-free, or ventless, gas logs. Since the chimney flue is closed during the use of these gas logs—if there even is a flue—99 percent of the 30,000 to 40,000 BTUs these gas logs kick out goes to heat the room. That means a warm space you’ll love to bask in.
The trade-off? That dancing, yellow flame. Since vent-free gas logs draw in your home’s interior air for combustion, the flame produced by vent-free gas logs will be bluer, smaller than and not quite as extravagant as vented gas logs. Another downside? Carbon monoxide can be released back into your living space and the logs may produce excess moisture. Although most ventless gas logs meet federal standards for carbon monoxide emission and come equipped with oxygen depletion sensors, these vent-less hearth products may not be legal in your state (a handful of states prohibit vent-free heating).
- Lightweight and durable, ceramic gas logs are ever popular because of their quick, radiant heat and glowing ember look. They also can be molded into more realistic configurations and can be separate, arrangeable pieces that mimic the look of real wood.
- While cement logs do not heat as quickly and may not be as durable as ceramic fiber, they are less expensive and a viable option if you use your gas logs only intermittently.