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...):
The abbreviation is meant to indicate one thousand thousand, M being the Roman numeral 1000. However, MM actually means 2000, not one million, in Roman numeration. MMb, MMbo symbols for one million barrels of oil; see megabarrel above. MMBF or MMBM symbols sometimes used in U.S. forestry for one million board feet. One MMBF represents a volume of 83 333 cubic feet or 2360 cubic meters. BM stands for board measure. MM Btu traditional symbol for one million Btu (about 1.055 057 gigajoules (GJ)), a unit used widely in the energy industry. This unit is also called the dekatherm. MMCF a symbol for one million cubic feet (28 316.85 m3, or 28.316 85 megaliters). MM scfd symbol for one million standard cubic feet per day, the customary unit for measuring the production and flow of natural gas.