Storage systems of various types are available for storing articles under a variety of conditions. These storage systems often are self-contained, i.e., they have contained within themselves everything that is necessary to carry out the storage function. In other cases, the storage systems are housed in an environment that contributes to the storage function. For example, storage compartments can be contained within refrigeration appliances such as household refrigerators whereby the storing functions performed by the storage compartments are augmented by the temperatures maintained in the refrigerators.
In particular circumstances, storage compartments that maintain the foodstuffs contained within them under conditions that extend the period of time during which the foodstuffs remain fresh, such as where vacuums are maintained within the storage compartments, are abetted in their food-preservation function by keeping the foodstuffs at a temperature somewhat above freezing in the fresh food compartment of a refrigerator. By way of explanation and clarification, the word “vacuum” whenever used herein is not intended to only mean a space empty of matter but refers to any circumstance where the pressure is less than the ambient pressure.