I guess I should have given a little more information in my first post.
We bought the home with an old wall unit in the livingroom. It is very expensive to run, my best guess is it is from the eighties, or early nineties.
It is a 18,000 btu unit that needs 220v, so the wiring is already there.
I also have 110v available close by.
The house is only about 750 sq. feet. I have been looking for a unit that will at least do 600-700 sq feet, but have noticed that most of the bigger units require 220v. I can probably find a 12,000 btu unit that uses 110v that could handle the space but I am afraid that it will be running too much to keep up on really hot days since 12,000 btu is rated for a space about 500sq ft.
The 220v would seem like it would be using too much energy even though it is energy star rated. And a 110v unit wouldn't seem big enough to handle the job. I really would hate to buy a unit and then not be able to afford to run it.
Thanks