Found the aforementionsed site, plus others, but they are either opaque
(don't reveal how they calculate... which, after the flap over the bad
'hockey stick' model that was used to justify Kyoto
http://www.jerrypournelle.com/view/view349.html#hockeystick makes me
mistrust them, as they are probably assuming we run our house hotter
than we do, our house is less well sealed than it is, or it's larger
than it is) or ask for data in arcane formats (i.e., AFUE for heat
pumps).

Also, a search for the conversion factors themselves was not
productive.

I did my homework first.