[Epa095]

What's special about RV heat pumps which makes them so bad compared to regular heat pumps? Heat pumps have gotten significantly better lately, and house-models are effecient down to -25C. Maybe the RV models you have tried are mostly older models?

[SigmundA]

RV heat pump are not that sophisticated because there doesn't seem to be much demand, they simply flip over to furnace. They are the same on the cooling side, they are no where near as advanced as a modern variable speed mini split.

There is no reason they could be more advanced with lower temperature support, they would just cost more. Many people put mini splits when making their own RV's because they work better and want to run off battery as much as possible.