Swamp Coolers work in the desert best and anywhere the relative Humidity is below 30% and their cooling quickly goes down with any higher RH Number. Installing lots of Foam sheets with a White Roof helps a ton. I put in a 12 Battery bank of 6 volt batterys and a 10,000 and 5000 btu units run off an inverter. A Charged bank,Solar and Alternator allow me to run all day and night till I Plug in the 100 amp charger. I also have a genny if needed,but never use.