Heating, Air Conditioning, Fridge, HVAC/Window vs. Portable unit
Jim, My house in Houston, TX was built cheaply in 1978. Our AC couldn't seem to adequately cool our 2000 sq ft home, so we had it replaced by people we've known and trust for years. It didn't make much difference. Our living room has a high ceiling & a loft area upstairs. The lowest temp we can get upstairs is 85 deg in summer. I've tried a portable unit in the past and it was a wasted investment. A big part of the problem might be that the loft is an open area. Should I try a window unit or is it a wasted effort? The room is far enough away from the central unit that it doesn't help a lot, even after replacing ductwork. I'm told raising BTUs would only cause system to shut off early without cooling entire house. Your opinion and time are appreciated.
If you have to choose between a "window unit and a portable unit" for the purpose of cooling an area, go with the window unit.
If you want an AC unit to cool the entire house the house needs to be closed, no open doors or windows, the supply and return air outlets, inlets need to be in the proper locations so as to cover the exposed areas, every area that has a supply diffuser needs to have a way for the air that blowers out to return to the AC unit, a supply outlet into an area like a bed room needs to also have a way for the air to return, you can't condition a room if the door to the room is closed unless there is a return in the room.
If I could see your house and how the system is installed plus do a heat load calculation I could tell you what you need to do?