I see that there are two designs for swamp coolers:
1. A true swamp cooler generally has a carboy sitting in a shallow pool of water with a a t-shirt covering the carboy and wicking water from the pool of water. A fan blows on the t-shirt causing water to evaporate thereby cooling the carboy.
2. A carboy sits in a container full of cold water. Generally, the level of water matches the level of beer. Generally, ice packs are thrown into the water once or twice a day.
What are the pros and cons of both designs? I'm interested in throwing something together so I can brew over the July 4 weekend.
Add: I'm doing a wit that I want to ferment at 70-75 with T-58. Ambient temp in my basement should not exceed 75.