To cover the basics, a portable air conditioner is called such because it can move. It is given this distinction because there are certain air conditioners that once they are put in place are fairly permanent and cannot be moved from room to room. Normally portable air conditioners are lighter than most window units and weight between 60-80 pounds, are on wheels and are fairly simple to transport.
Portable air conditioners are not totally stand alone however and do require that you are able to vent the warm air that the conditioner “sucks” out of the air. This is done via a flex tube to a window, door or other existing vent already in place. The hot air just needs to get out of the room for the portable air conditioner to do its job effectively.
You will find that most manufacturers will supply a flex hose with your air conditioner purchase and longer than standard 5-7 feet lengths can be purchased if needed. One thing to remember is that the longer the hose, the harder your portable unit needs to work to pump out the hot air. Try to stay away from distances longer than 15 feet and sharp kinks or obstructions in the hose.
As long as you clean your air filters regularly and do not allow water to stagnate in your drainage basin and cause odor, you can expect many years of quality cool air from your portable air conditioner while using less energy than a larger non portable unit.