Because they are more efficient than decorative gas logs, gas fireplace inserts can cost about one-third less to operate. Inserts have glass separating the flame from your living area, which adds to their efficiency. Because the fireplace is sealed, gas fireplace inserts prevent heat from escaping up the chimney, even when it's not in operation. They can be turned on with a switch, a remote control, or automatically, with a wall-mounted thermostat. They are installed with a vent to the outside.
Some models also use fans to circulate heat into the room.
Stand-alone gas fireplaces typically stand away from the wall and are very similar to a wood stove in appearance. Stand-alone gas fireplaces come complete with gas logs and glass doors. They usually produce radiant heat and, in some cases, have a blower and heat exchanger to produce overall efficiencies of up to 78 percent. A built-in gas fireplace is a good choice if you're remodeling a room or building a new home. Not only do gas fireplaces cost far less than constructing a masonry fireplace, they give you the versatility of placing a hearth almost anywhere you like.