I live in south fl, so i deal with the heat and it sucks. i got a decent size plastic container from wal mart, tall enough so only the top 1/5 of my carboy sticks out over the top. fill that container up with water, stick your carboy in so its sitting in the water. I froze about 4, 2 liter bottles(old coke bottles) and added them each morning, evening and before bed, this helped keep the temp down, and even when i was at work for long days, the water holds the temp better then the air. try that, its the best i can do without buying another fridge.