how hot do you expect it to get back there ?
where do you live ? if your living in a place like Arizona , your going to need a lot of cooling .
just a thought , the fan switch used on an attic fan , it would only turn when it was needed , you might even be able to use an attic fan too
this way even when the fridge cycled off if the area was still warm , the fan would continue to run until it was not needed
where do you expect "take up air" to come from ? if it's coming from the room the fridge is in , this system could increase your heating /cooling costs if ducted outside
have you thought about the increased noise level , with a fan running ?