The heat system in a home is a pretty fundamental thing. Not surprisingly then, most of us want to know what we get with our systems - so how do we compare efficiency of home heating systems?
It can be pretty difficult and a lot of the quoted figures just make things harder. For instance, a gas heating stove with an efficiency upwards of ninety percent is though of as very efficient, but you can easily find that the best rated heat pumps come in at several hundred percent efficiency.
We are often comparing apples with pears. Or more precisely gas with electricity. Gas is brought straight out of the earth then burned for our heat, so a ninety percent efficient unit is only wasting 10% of the natural heat of gas. Electricity on the other hand has to be generated, and this generation and distribution process tends to be inefficient - sometimes the generation is only 30% efficient. So it is good that heat pumps make the best use of electricity, but it still is inherently inefficient.
And what about comparing radiant heating systems with forced air systems? Some people argue that heat outputs cannot be compared because radiant heat tends to make people feel warmer so they drop the thermostat!
Other questions like home heating with propane compared to natural gas can be answered by looking at the market prices. In fact this is not a bad way to answer all the questions - the most efficient might simply be the one that costs least to run. If only fuel prices were not changing all the time...