Gas
Gas fireplaces are designed to burn either natural gas or propane. They emit very little pollution, need little maintenance, and can be installed almost anywhere, especially in a new home. Gas fireplaces have BTU ratings that measure how much heat is produced by the hour. They are also rated by fuel efficiency; that is, the amount of fuel consumed to generate heat and attain the ideal BTU. Direct-vent and top-vent gas fireplaces have an efficiency rating of 40 to 80 percent, meaning that, at 80 percent efficiency, every dollar spent on fuel gives you 80 cents worth of heat. When shopping for a gas fireplace, look for the following:
• Direct-vent design. This is the safest and best option for fuel efficiency.
• Automatic starter. Makes the use of a pilot light unnecessary. Pilot lights can consume nearly half the gas used to run your fireplace for a year.
• Ceramic glass front. Ceramic glass is more efficient at transmitting heat from the flame into the room than tempered glass and it is shatter-resistant.
• Quiet, squirrel cage-type fan to force convective heat into the room.
• Secondary heat exchanger. This extracts more heat from the combustion gases and transfers it to the home.
• Insulated outer casing. This prevents heat loss through the walls when the fireplace is on an exterior wall.
• Wide turndown ranges, allowing more variation in the amount the heat can be reduced, or an automatic thermostat control that keeps the temperature at a more constant level.
• Ducting capabilities. Some units can be connected to ductwork so that heat can be distributed to remote areas of the house.
Denatured Ethanol
Ethanol is a clean, safe, and environmentally friendly heating fuel. When it is burned its emissions are similar to human breath—mostly water vapor and carbon dioxide—so no venting is needed. Most North American ethanol is made from corn, and the rest from switchgrass and other plants. Today, The Fire Company, an Australian firm, is the only manufacturer of a denatured ethanol fireplace. It’s called the EcoSmart Fire and is distributed in the United States.
Gel
Gel fuels are usually thickened ethanol that comes in a can, similar to Sterno. Each can burns for two to three hours; the fuel produces heat with out any accompanying fumes or smoke. Gel fireplaces look like traditional fireplaces with flames, and some models even make a crackling sound that emulates a real fire. They are ideal for space heating and creating a warm ambience. They are easy to maintain, energy-efficient, and cost effective. A mid-level unit will cost in the neighborhood of $1,000.