This is my very simple swamp cooler set up. Ambient temperature is usually 68°F. I can drop the temperature of the fermenting beer 8°F when the fan is blowing on the wet towel. Using ice bottles in the water tray would drop the temperature considerably more.
Enter "swamp cooler" in the search box for more ideas. You will only need to keep the temperature of the beer controlled during the first few days of active fermentation. This can be three to five days usually. After active fermentation is over the temperature of the beer can be allowed to slowly rise.