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.
Step 2: Step Two: Build It.
place a zip tie every 6" of copper. Once finished coiling, attach vinyl tube to feed end of copper.
Then, lead the tube to the pump. Connect it. then, cut the tube in half. Clamp the remaining half of tube to the return line, and lead it back into the cooler. Use the hose clamps to clamp down the connection between the copper and the vinyl tubing.