For the air cooler, the following will be involved in the problem, there are two main, specifically as follows:
Question 1: What are the types of air coolers? Which one is the most basic?
Question two: air cooler frame, water tray of what are the technical requirements?

Since these two issues, put them up, then below, Xiao Bian to explain in detail about it, I hope we can help and inspiration.
Question 1: What are the types of air coolers? Which one is the most basic?
Air cooler, which can be divided into dry, wet and dry - wet combination of these three, of which dry is the most basic, while wet and dry - wet combination is the development of the type.

Question two: air cooler frame, water tray of what are the technical requirements?
1. The air cooler frame, the weld on the water tray should be uniform and smooth, and there is no problem such as desoldering.
2. Its flatness should be less than 1m, there is deviation, then it can not exceed 1mm.
3. The water dish should be leak test, check whether there is leakage and other issues.