See The Right Product for product information. Covering the unit is not necessary. Air conditioners are manufactured to withstand all possible climate changes. In fact, rain helps keep your unit clean. Of course, because heat pumps run all year long, they should never be covered.
Humidity is a problem in many areas.
The best way to control excessive humidity is to have a system that runs longer at lower speeds. Variable speed air handling equipment runs at very low speeds, which keeps the air circulating against the cooling coil and removes much more moisture than conventional systems. At these low speeds, the variable speed motor uses much less electricity than conventional motors. There are a couple. One is that you get constant filtering of the air in your home.