Question

What would hapen to the room temperature if we let the refrigerator door open?

Answer 1

The room would get warmer!
refrigerator as a device that transfers heat from inside a box to its surroundings. The room around a refrigerator is warmed as it receives the heat removed from inside the box. 

If you leave the door open, heat is merely recycled from the room into the refrigerator, then back into the room. A net room temperature increase would result from the heat of the motor that would be constantly running to move energy around in a circle

Answer 2

Answer:

• As a refrigerator is a heat pump.  
• Hence it extracts heat from a low temperature reservoir and transfers it to a high temperature reservoir.  
• Thus, refrigerator exhausts more heat into the room than it extracts from it. Hence, the room will become warm.