The fridge that the previous residents of my house paid $4,000 for has sat quiet and warm since noon. Around 6pm I checked under the freezer drawer to see if anything had thawed out and discovered a centimeter-thick layer of ice on the bottom of the freezer. Actually, by 6pm it was more like a 5 mm layer of ice floating on 5 mm of water. Fifteen minutes and two towels later I managed to get most of the ice into the sink and most of the water out of the freezer. But wow, scraping a half-liter of rime ice from your freezer is not fun.
I can't even guess how long condensation has been pooling there. Obviously there's something else wrong with the freezer. And I have a working hypothesis.
According to the repair guys, if the freezer thermostat gets too frosty, it won't trigger the defrosting heaters that remove condensation from the freezer. The heaters being off would also allow the condensation drain to freeze shut, so even if they did turn on, the water might not have anywhere to go. And the reason this happens with the windows open could be simply that the warmer outside air contains more moisture, which causes more condensation, freezing the thermostat, and starting the downward spiral of events culminating in me fantasizing about dropping the whole unit onto the KitchenAid design offices from a helicopter.