The only reason I asked about air distribution is that you were questioning the use of a mini split heat pump or a central HVAC heat pump system. They both ultimately do the same thing, but are installed and perform differently.
Like I said, the mini split system will only blow air into the room it is installed, so if you wanted to heat/cool your whole house, you'd need several of them. The main benefit would be you could save money by zoning - heating/cooling only the room(s) you occupy if you install say 1 in the living room and 1 in each bedroom.
The central unit, of course, would heat/cool the whole house to the same temperature all the time.
Portable units are fully self contained, and simply have an exhaust duct to send out the window. Heat pump windows units are just that, window air conditioners that reverse cycle and produce heat when it's called for.
In a nutshell, I was simply trying to point out that your needs will dictate which system you decide on. If you're a single person, then paying to keep the whole house the same temperature may not make financial sense and the break-even point will probably be longer. But the cost comparison of a central HVAC heat pump system to a mini-split heat pump are apples-to-oranges because of their intended use and operation.
Thanks, and I hope I better clarified the reason for my initial question...