Hi. We are considering buying an old house (built late 1800's), wood frame, that has central heat & air downstairs, but not up. The upstairs is only a partial upstairs--at the top of the staircase you can turn either right or left and on each side there is a room I would estimate is about 12' x 12'. These 2 rooms are the only thing upstairs. Both rooms have a fairly large storage space behind them that is accessible through a door--the storage spaces are about the size of a really large walk-in closet and are unfinished--like attic space.
What we are wondering is, if we bought the house and wanted to use the two upstairs rooms as bedrooms for our boys, what would be the most efficient and least costly way to add heat and air up there? I have seen mention of split systems, ductless systems, etc. and I have no clue what those are. Also, what about the kind of heat/ac units that hotels have? What would be the cheapest and easiest to buy and have installed and would not skyrocket our electric bill when used? We live in the south, so a/c is necessary almost 9 months of the year.
Any advice would be appreciated. Thanks!