The refrigerant flows through the coils on the back or under the freezer and through an expansion valve to the inside of the freezer. As the refrigerant passes through the expansion valve the pressure drops and hence the temperature also drops.
The noun MM has 1 sense: 1  1. a metric unit of length equal to one thousandth of a meter. 2  Meaning: 3  A metric unit of length equal to one thousandth of a meter. 4  Classified under: 5  Nouns denoting quantities and units of measure. 6  Synonyms: 7  millimeter; millimetre; mm. 8  Hypernyms (mm is a kind of...):
A millimeter (abbreviated as mm and sometimes spelled as millimetre) is a small unit of displacement (length/distance) in the metric system. The metric system, sometimes considered synonymous with the International System of Units (SI), is used throughout the world in the sciences and is the standard of measurement for science engineering,technology and Mathematics .