The cooling effect in refrigerators is caused by a combination of temperature, pressure and volume. These factors help refrigerators keep food and drinks cold by reading and regulating temperature settings via thermostats, and maintaining proper pressure and air volume.
Temperature, pressure and volume are regulated in a complex system. Refrigerators contain gas, which is drawn through a long line at low pressure and low temperature. Then, gas is condensed or compressed using electricity. Next, it is converted to a higher pressure, which in turn causes internal temperatures to rise. Heat and electricity are then transferred to a unit called a condenser, which removes excess heat. As a result, gas begins to cool, and ultimately condenses into a liquid form. According to IOR, the residual heat is then released through a pair of cooling fans located in the back of the unit. After cooling, the liquid is transferred to an expansion device, which quickly and drastically reduces its pressure. The liquid then expands and transforms into a gaseous or vapor substance. The transformation causes a cooling effect, which allows the cool vapor and any residual liquid to cool the air in the refrigerator compartments; they do so by blowing through the expansion device. The trace amounts of liquid absorb warm air in the refrigerator, and converts back to a gas, then retreats through the compressor to begin the cycle again.