| 摘要 |
PURPOSE:To increase the effective volume of a freezing chamber and prevent frosting in a duct surely by a method wherein a cooler and a cold air circulating fan are received in a cooling box body, in which a heat exchanging chamber is defined, and a heater, heating a returning duct, communicating a cold storage chamber with the heat exchanging chamber, and returning cold air, is buried in the heat insulating back wall of a heat insulating box body. CONSTITUTION:Cold air, whose heat is exchanged in a cooler 11, is sent into a freezing chamber 8 by a circulating fan 12 to cool foods to be cooled and, thereafter, the cold air is returned into a heat exchanging chamber 13 to effect heat exchange in the cooler 11 again. On the other hand, one part of the cold air, whose heat is exchanged in the cooler 11, is sent into a refrigerating chamber 6 to cool the foods to be cooled and, thereafter, is returned into the heat exchanging chamber 13 through a returning duct 23 to effect heat exchange in the cooler 11 again. In this case, the cold air, passing through the returning duct 23, is heated by a duct heater 24 whereby frosting in the duct 23 can be prevented surely while the returning duct 23 is buried in a heat insulating back wall and, therefore, the cold air can be heated efficiently by the duct heater 24 having a small capacity. |
