Responded to a no cool call, found unit to be a mini split. Checked unit pressures they are correct. After inspecting unit I found the coils to be the issue customer said it would freeze and unfreeze. Coils are covered in rock dust and grit. Cleaned both evaporator coil and condenser coil. Unit is at least 4-5 years old in a rough air environment. This will continue to happen Due to the environment the unit is in if not cleaned regularly. Pulled drain as well.