Refrigeration
Grocery stores often package our food sources by the pound, we then combine those food sources when cooking, it is quite often that after meal preparation and eating that we have leftovers. Uneaten food can either be refrigerated or frozen to consume later.
Prior to refrigeration being invented our ancestors would have to bury food below ground to preserve it as the temperature is cooler below the earth's surface due to a decrease in sunlight. Although the first mechanical refrigerator was built in the 1800's the first electric refrigerator was invented in 1913. Around 37yrs later the first freezers were developed with automatic ice makers making their appearance a decade later. In this article I will discuss how the refrigerator, freezer and deep freezer operate in an effort to preserve your foods today.
For a refrigerator to work efficiently the appropriate temperature must be at 40 degrees Fahrenheit which is 4.44 degrees Celsius. To achieve this temperature liquid refrigerant/coolant is condensed into a gas that evaporates. This cycle is repeated over and over again to ensure that your refrigerator maintains its temperature.
The major parts of the refrigerator are:
☆ Capacity control system controls the on/off cycle of the refrigerator system by controlling the compressor.
☆ Compressor contains heat gas that is released onto the condenser coils located on the back of your refrigerator.
☆ Condenser coils convert the heat gas into liquid refrigerant/coolant.
☆ Thermostat expansion valve converts the liquid refrigerant/coolant into a gas that flows through the evaporator.
☆ Evaporator is where the refrigerant/coolant gas travels through the evaporator coils located at the top of your refrigerator inside the freezer to absorb heat.
To freeze food in a freezer the temperature must be 0 degrees Fahrenheit which is -18 degrees Celsius. The freezer uses the same components as the refrigerator however with the evaporator coils absorbing heat at the top of your refrigerator unit results in the temperature being cooler in the freezer verses the refrigerator.
A deep freezer is a additional kitchen appliance that is used to preserve larger quantities of food sources for a longer period of time due to its larger space capacity. The deep freezer must also maintain a constant internal temperature of 0 degrees Fahrenheit/-18 degrees Celsius. It also functions in the same manner as a regular freezer.
A mini refrigerator works in a similar manner as a standard refrigerator meaning that heat is absorbed with results in a lower temperature inside the compact unit. However the temperature inside a "mini fridge" can range from 35-42 degrees Fahrenheit/1.66-6.11 degrees Celsius which is why it is good for chilling beverages and soring food items short term.
To learn how refrigeration is used to transport our food sources click here.
