Often times you will find people prefer to buy a split air conditioner over a window unit. Whereas the window unit is made to fit neatly into a small window opening or into the wall, each split unit has two sections. One section is installed inside the room while the other is installed outside.
Perhaps the main reason people prefer this type of split air conditioner is that it looks much better than the window unit, similar to the best portable air conditioner. It is usually deliberately made to blend in well with the room and you often have a choice where you want to install it. It can sit on the floor or be suspended from the ceiling, or even attached to the wall.
Another plus is that split units can service more than one room, whereas the typical window unit is only used to air-condition one room at a time. Because of the way they are installed, they often provide better security for the homeowner. Burglars have been known to take out a window unit and crawl through the hole into the house.
The main drawback with using this type of air conditioning unit is that it is usually quite a bit more expensive than a window unit. One of the more expensive brands is Sanyo. A small Sanyo 9000 BTU unit could cost you around $950 where as a similar cheaper unit made by Klimaire for example will only cost $530. In fact a 12,000 BTU LG unit is actually cheaper than the smaller 9000 BTU Sanyo unit.
Of course when purchasing a split air conditioner there are other things to consider aside from cost alone. Try to find a unit that offers a good three-year warranty. Also look for those that are designed to be energy conserving as you will find that you end up saving quite a lot of money on your utility bills if you opt for one of these types of units.