I understand the icing you are experiencing, as I am also. Its been a year for the record books.
The answer is NO, No emphatically. This system needs ventillation and open spaces to draw and create ventillation.
You could do something to stop the water from hitting the unit by creating a diversion on the roof or making an awning high on the wall to shed the water off the system, but to build any sort of shelter is a no.