I know some herp people who have attempted to include thermoelectric cooling devices into terrariums. How they've turned out I do not know. Since we don't read about it anywhere I gather it's been difficult.
Thermoelectric coolers are the components found in the electric Igloo coolers, etc. The ones you run off the cigarette lighter in a vehicle.
I think thermoelectrics require a lot of insulation and won't do well with the ventilation required by most herp species.
A swamp cooler won't work, obviously, due to the high humidity in most of Florida. They really don't work anywhere but the driest of areas.
I suspect you're stuck with window air conditioning. Run one through a cooling thermostat like a Ranco and you should be able to maintain the desired temps easily.