There's nothing quite like curling up in front of a warm fire in a wood-burning fireplace, but for all the ambiance of the crackling logs and glowing embers, it's not the most efficient way to heat up a room. That's not to mention the hassle and expense of buying firewood and having the chimney swept annually. For these reasons, many homeowners choose electric or gas fireplaces instead.
Of course, one downside to those alternatives is that their use adds to your monthly utility bills. But depending on what type of fireplace you have, what settings you use and how often you use it, a gas or electric fireplace can be an inexpensive and effective way to make a room look and feel cozy.
Let's start with electric fireplaces, which have grown in popularity in recent years due to their energy efficiency, the variety of styles and the ease of installation. Most electric fireplaces draw about 1,500 watts and can heat spaces up to 400 square feet. There are larger models available that consume more energy and heat larger spaces, but since electric fireplaces are only for zone heating, the standard 1,500-watt models work for most homeowners.
Based on the national average kilowatt-hour (kWh) rate of 12 cents, a 1,500-watt electric fireplace will cost around 18 cents per hour with all settings at maximum. If you use a lower heat setting, the cost per hour can drop by several cents, and if you only use the LED-backlit fire display and not the actual heater, the cost is often less than one cent per hour.
To calculate the monthly cost of your electric fireplace, you'll only need to add up how many hours a month you use it and multiply that by the cost per hour. Using our example from above and an estimated winter usage of two hours a day, or 60 hours a month, our fireplace with all the settings at maximum would cost about $10.80 per month.
Estimating the operating cost of a gas fireplace is a little trickier. First, these appliances fall into two broad categories: gas log sets, which sit inside a traditional wood-fire fireplace, and gas fireplaces, which are self-contained units whether or not they're used in conjunction with traditional fireplaces. Log sets may use anywhere from 60,000 to 90,000 BTUs per hour and are very inefficient for heating, since most of the heat goes right up the chimney. Gas fireplaces come in a much larger range of BTU outputs, from about 10,000 to 70,000 BTUs, and they heat more effectively.
Second, log sets and gas fireplaces may run on either natural gas or propane, and the price difference between these two fuels can be significant. Propane is generally more expensive, but for residents in rural areas that lack natural gas hookups, it's often the only option for heating fuel. The prices of both fuel types fluctuate, but natural gas prices are more stable.
Once you know the BTUs of your fireplace and your fuel type, it's fairly easy to calculate the cost of operation. Let's say you have a 40,000 BTU natural gas fireplace, and your gas rate is $1.20 per therm (one therm is equal to 100,000 BTUs). Here's how you calculate the cost per hour:
(40,000 x 1.20)/100,000 = .48, or 48 cents per hour
To find the operating cost of that same fireplace using propane, let's assume your propane cost is $2.50 per gallon (one gallon of propane is equal to 91,000 BTUs). The formula, then, would be:
(40,000 x 2.50)/91,000 = 1.1, or $1.10 per hour
Keep in mind that if you have a gas fireplace, there may also be some small electrical costs associated, such as if your model has an electric fan that blows heat out into the center of the room.
As with electric fireplaces, all you need to calculate the monthly cost of your gas fireplace is your hourly cost and the number of hours you use it per month. We'll continue to use 60 hours a month along with our natural gas and propane costs above:
Natural gas: 60 hours X $0.48 per hour = $28.80 per month
Propane: 60 hours X $1.10 per hour = $66 per month