Refrigerator

A bottom-freezer refrigerator comprising:

• a refrigerator housing including an upper portion and a lower portion which are separated by an adiabatic partition wall, said lower portion having a freezer compartment defined therein, and said upper portion having a refrigerator chamber, a crisper chamber and a low-temperature chamber therein;
• a first cooler in said upper portion;
• a first circulating fan in the vicinity of said first cooler;
• a refrigerator air passage interconnecting a discharge side of said first circulating fan and said refrigerator chamber;
• a low-temperature air passage interconnecting the discharge side of said first circulating fan and said low-temperature chamber;
• a second cooler in said lower portion;
• a second circulating fan in the vicinity of said second cooler;
• and
• a valving device for switching flow of a coolant in a coolant circuit, so as to allow the coolant to flow through said first cooler and said second cooler when said valving device is in a first position, and to allow the coolant to flow through said second cooler without flowing through said first cooler when said valving device is in a second position;
• wherein said refrigerator chamber, said crisper chamber and said low-temperature chamber each are to be cooled by said first cooler operating in cooperation with said first circulating fan such that said low-temperature chamber attains a temperature lower than that attained by said refrigerator chamber, and said freezer compartment is to be cooled by said second cooler operating in cooperation with said second circulating fan.