An interesting study, but spatially non-uniform dynamic thermal location and local partial biomass availability seem like factors here. While direct heaters, gr

An interesting study, but spatially non-uniform dynamic thermal location and local partial biomass availability seem like factors here. While direct heaters, ground source heat pumps in particular, can be exceptionally efficient and functional year round, they ultimately have fixed exchange locations and must bring the whole house volume to temperature. Whereas a cat heater is dynamic: for example while I am sleeping the cat is liable to apply all 15 watts directly to my face. I can anecdotally report a significant insulation effect as well. Or while I'm desperately trying to complete a final sprint the cat may decide that my keyboard is the ideal radiative location. A proper heating model probably needs to take this into account albeit with a lot of chaos and quantum theory mixed in as the cat may or may not be providing heat until observed. And cats in general are equipped with local biomass harvesting and conversion capabilities that may further alter supplemental fuel costs. Never the less I certainly look forward to continued research on this topic!