Hmmmm ... our first Carrier heat pump in the house went 32 years.
Our current very high efficiency Trane heat pump is only 5 years old now, but has so far been superlative and has reduced our electric bill around 30-40% from the previous Carrier heat pump. I did a lot of research before deciding on our current model. It has a variable speed fan and variable speed Scroll compressor - all computer controlled. Of course this level of heat pump technology is probably not yet available in motorhome units.
Our motorhome's ducted A/C and ducted propane furnace with a digital controller have been great. However our propane tank capacity is somewhat larger than that usually found in small Class C motorhomes, so extended use of the propane furnace does not present much of a refilling nuisance. Since the motorhome is small for the furnace size it cycles well and hence doesn't tax the battery bank heavily, either.
