Nor-Lake Freezer Norlake Refrigeration 6' x 6' Kold Locker Walk-In Freezer - 6' 7'' High w/Floor "amana refrigerators cooling vacuumed" Questions

...cooling frost has built up on my 7 yr old Amana 'bottom freezer' rear/vented freezer wall. 1 month ago vacuumed/cleaned the filthy condensor coils on the bottom and manual defrosted. worked fine but ...