For years I've wondered if a dual-hose portable heat pump/air conditioner would work as a poor man's ductless minisplit heat pump. The advantage, as my logic went, was that I didn't have to drill any holes or charge any refrigerant.
I bought a 14kbtu portable heat pump (Edgestar AP14001HS Portable Air Conditioner)
I did some primitive temperature and airflow measurements.
I was impressed by the overall quality and the 11.2 EER, but what I found was very disturbing.
There is so much internal leakage, that the heat pump blows almost twice as much air out of the house that it pulls in. That difference in air volume gets sucked from outside into the house. The net effect of that is to reduce the COP in heating mode from the advertised 3.3 to roughly 1.4.
For heating, that makes it hardly worth the extra money over a resistance heater. I might as well have purchased an electric resistance heater with a COP of 1.0. In the air conditioning mode, this problem makes the unit worthless except for spot cooling. A window unit would work three times better at a lower first cost.
Has anyone seen a dual hose unit that actually works well?