Clean and Efficient Fuel?
If you've been leaning toward natural gas based on its fuel efficiency, you may be interested to know that you can reduce your fuel usage by 25-40% by upgrading your current heating equipment to modern efficient equipment, regardless of what fuel source you use.
And, while natural gas is touted for being a clean energy source, propane is actually the cleanest fuel choice available. Propane emissions are identical to natural gas when burned, but unlike natural gas, propane doesn't produce methane, a harmful greenhouse gas. See the graph on the right from the U.S. Energy Information Administration for a look at the methane output of natural gas.