Work Step by Step
By leaving the oven door open, one effectively just makes the heating elements warm up a bigger space. The heating elements simply dump heat into the room, and no thermodynamic cycle is involved. On the other hand, leaving the refrigerator door open does not cool the room. Normally, the refrigerator removes heat from the inside compartment but dumps that heat, and more, into the kitchen via the warm condenser coils on the back or underneath. The kitchen becomes warmer overall, not cooler, with the refrigerator door open. Only if you had the refrigerator dump heat into another room (or outdoors) would leaving the door open serve to cool the kitchen. In effect, you would have turned the refrigerator into an air conditioner, as this is exactly how they function.