New fuel cost calculator compares different home heating methods

The folks at BuildingGreen have always been a few steps ahead of the curve. Their monthly newsletter has been the gold standard for information on sustainable building since it began publication in the early 1990s, when many of today’s greenies were still learning long division. Lately they’ve been adding more info for homeowners, including this new fuel cost calculator that helps you figure out if it pays to upgrade your home’s heating system.

The tool prompts you for info about your current system, then lets you pick from among seven common fuels, including propane and natural gas. (It automatically fills in average costs for fuel in case you don’t happen to have the price of natural gas at the tip of your tongue.) It then compares fuel costs per million Btu (MMBtu) of delivered heat. Why does it make sense to do it this way? I’ll let BuildingGreen explain:

While we purchase some fuels by the energy content of the fuel, we purchase others by volume or weight—and we use different units for different fuels. Heating oil, propane, and kerosene are sold by the gallon, natural gas by the hundred cubic feet (ccf) or therm (100,000 Btus), firewood by the cord, wood pellets and coal by the ton, and electricity by the kilowatt-hour (kWh).

To further complicate matters, the amount of usable heat we get from a fuel also depends both on the efficiency of a given heating device and on how efficiently that heat is distributed to the conditioned space.

Lucky for us, their calculator accounts for all these complications. Home heating contractors get busier come fall, so although we’re in the midst of summer’s warm embrace, it pays to do a little math right now if you want to slash your utility bills later.