This probably won't help much since I have only a 10-gallon tank, but I've found a great deal of success using a combination of aquarium fan and ice probe chiller. It's not exactly a traditional chiller, but it only costs about 120 USD. For a tank that size though, you'd probably want 2 or maybe even three of them, but they are SUPER quiet. I'm a pretty light sleeper and have had it set up next to my bed with absolutely no problem.
Back to the fan though, they really do help, but since they cause an increased rate of evaporation (especially in a dry environment), you'll probably want to have some distilled water on hand to top off the tank. The pure part of the water is what evaporates, leaving behind all the minerals. If you constantly refill with tap water, you could end up with a toxic amount of minerals. Water changes with de-chlorinated tap water is fine, but just for topping off, you should use distilled water.