Cost of Operating a Gas Fireplace
Inexpensive and easy to maintain
The cost of running your gas fireplace will depend on the heating efficiency rating of your fireplace, the number of hours of use and the cost of natural gas. The cost of natural gas is often measured in Therms, or thousand cubic feet (Mcf). One Therm equals 100,000 BTU, and one cubic foot of natural gas contains approximately 1,000 BTU's. So 100 cubic feet of natural gas are approximately equal to one Therm.
It is important to note that if the pricing is equal (1 Mcf being roughly 10 times the price of 1 Therm) then there is no particular advantage to having your usage measured in one way or the other. Whether you're paying by the Therm, the Mcf, or in many countries by the cubic meter (m³), your bill is really about the cost per BTU of energy. A simple example would be buying a large or small container of milk; just as long as a half gallon is half the price of a gallon, the choice makes no difference.
Equation for Determining Hourly Natural Gas Price:
If your bill uses Therms:
BTU Rating of Fireplace ÷ 100,000 x Gas Rate per Therm = Hourly price tag
If your bill uses 1,000 cubic feet of gas (Mcf):
BTU Rate of Fireplace ÷ 1,000,000 x Gas Rate per Mcf = Hourly price tag
So using that equation, we'll determine the hourly rate for the following example: the fireplace runs at a rate of 50,000 BTU/hour, the cost of 1 Therm equals $0.65 and the cost of 1 Mcf equals $6.50
So, if your gas bill is measured in Therms you get:
50,000 BTU/hour ÷ 100,000 x $0.65 = $0.32/hour
And if your gas rate is measured in Mcf, the results look like this:
50,000 BTU/hour ÷ 1,000,000 x $6.50 = $0.32/hour
Equation for Weekly, Monthly or Annual Rate:
Simply multiply by the number of hours. Using the same example, we'll multiply by 12 hours per month.
BTU Rate of Fireplace ÷ 100,000 x Gas Rate per Therm x Number of Hours= Monthly Cost
(50,000 ÷ 100,000 x $0.65 x 12 = $3.90/month)
BTU Rate of Fireplace ÷1,000,000 x Gas Rate per Mcf x Number of Hours= Cost
(50,000 ÷ 1,000,000 x $6.50 x 12 = $3.90/month)
Given that some people like to use their gas fireplace often and others very occasionally, your operational costs will vary. In addition, natural gas prices fluctuate seasonally as well as regionally, so for accurate numbers be sure to check with your gas or utility company for your actual rate.