It is very low cost to operate, compared to a central a/c, and provides spot cooling/heating, only cooling/heating the areas you want to cool/heat, heatly.
It is also eco friendly, because it uses water as refrigerant, and it can multi-task, cooling/heating the room, while cooling/heating your beverages (or whatever) in the cooler.
Step 1: Step One: Supplys
Salvage from the house(or Walmart):
1 Box Fan
Est. cost $0-$25
Buy at Lowes:
1 Smartpond 155 gal/hr fountain pump
1 20' box of 1/4"(ID) copper tubing
1 20' coil of 3/8"(ID) vinyl tubing
2 hose clamps
1 pack of zip ties
1 Cooler-32qt(8 gallons)
Est. Cost $50.00
Congrats. You just got through step one.