S.g.

I have a 20 gallon in my bedroom. There's no AC in that room (only room in the house without AC- go figure ). The tank's temp reaches 82-83 without a fan or chiller. Placing an eight inch circular fan, blowing directly at the center of the tank (not across the top) and on the lowest setting (has high and low only), brings the temp down to 80. Since it's not blowing across the top of my tank, it doesn't seem to increase the evaporation. Might give that a try.

82-84 is a little too high for my taste, especially since it leaves no margin of error.