York Package Unit ages - HVAC-Talk: Heating, Air & Refrigeration DiscussionCould someone with a decoder please let me know the age of a few package units I have? 1st Unit: Model D1SS120E03046B, Serial # NAPM038498 2nd Unit: Model D1SS090G20046B, Serial # NAPM022141 3rd Unit: Model D1SS120E03046B, Serial ...