Suppose you try to cool the kitchen in your house by leaving refrigerator door open. What happens? Why? Would the result be the same if you left open a picnic cooler full of ice? Explain the reason or any differences?
If you open the refrigerator door, the house will heat up. The heat removed from the air by the refrigerator coils is put back into the air by the condenser coils, plus some more produced by the motors. Net result is more heat in the air. However, a cooler full of ice will cool the air, since every gram of ice that melts removes the heat of fusion of ice from the air. In addition, the cold water that results also removes heat from the air when its temperature increases to room temperature.
it depends how long you leave the ref / cooler open. the ref has a continous supply off electricity that produces low temperature. if your kitchen is small and the cold does not dissipate quickly into the other rooms or outside the house, it will cool your kitchen... continously. in fact if you do this, ice will form to the edges of your chiller and you wont be able to close the door. now, the cooler has a limited supply of low temperature and your ice will melt... the kitchen and cooler will eventually reach an equilibrium temperature and then will drop til it reaches what you call room temperature (the temperature before you left the cooler opened). now, if the refrigerator is unplugged, it will behave the same way as the cooler.
The refrigerator is a heat exchanger. The heat is pulled out by the cooling process, usually a freon condenser. The heat taken from the inside of the fridge is released out the back of the fridge in the form of heat. There is some loss of energy running the condenser which is also released as heat into the kitchen. If you open the door you will initially have a colder room but the fridge will attempt to cool down and release more heat into the kitchen than what you started with because of the mechanical energy released in the form of heat by the condenser. The cooler full of ice will cool the air until the contents of the cooler reach room temperature again.
