What kind of fridge? If it's a Nova Cool it should already have an output terminal on the controller that will drive up to 0.5A at 12VDC.
Actually any fridge with a Danfoss compressor should have that terminal.
Do NOT use two fans. Use one fan that is large enough to do the job. I made the two fan mistake years ago and the two set up an unholy racket. Each fan individually was dead quiet but the two together sounded like a tiny jet engine. Harmonics drove me to go for the single larger fan. I used a single 4" fan that draws about 0.18 A, well within the Danfoss ability.
Runs only when the fridge operates.
Before I forget again use a diode to snub any voltage spike from the fan. Failure to do that could damage the output over time. a 1N4007 should do the trick.