@Tiddyoggy I do not have a split system, just one small wall unit. When I looked into this a while ago it seemed that MOST split systems had crank heaters of various power levels. The exception seemed to be the more expensive units. I did note that the efficiency figures were only quoted for when the units were operating, not for standby. This unit being in a rental property I am assuming it will probably be the cheapest the owner can purchase, but I could be wrong.