What's the proper way to arrange ductwork under a downdraft evaporative cooler mounted on a roof? Is it supposed to be sloped in some way or provided with a drain?
A friend has an evatporative cooler mounted on her roof. The downdraft cooler has sometimes pulled water from its pads into the ductwork. This caused the duct below the cooler to rust and the water can leak through it and through the ceiling in a hallway. I think a perfectly adjusted evaporated cooler won't pull water off its pads, but since these coolers are refitted every season and since there are factors like wind, it's unlikely that the cooler will always be in perfect operation.