Back on 2nd November 2002 I put a 90mm Sunon ball bearing fan inside the refrigerator, aimed at the evaporator panel for the purpose of improving the heat transfer. That, and a pair of fans at the bottom of the condenser behind the fridge improved the compressor duty cycle from 60% to 31%. Halved the power consumption. But that's another story. The point is, the fan inside the fridge is still going just fine after 144,768 hours 24/7 in a 4 deg C ambient as of today. We did some life tests of fans at work some time ago and at 70 deg C some would only last a few months. Temperature sure seems to make a difference!