While a lot of people own fridge freezers, not many of us really understand how they work. Knowing their components is crucial when it comes to troubleshooting a problem or doing a repair. With that being said, let’s take a look at exactly how they work.

Components

One common belief associated with fridges is that they work by making things cold. This isn’t true. They actually work by removing surrounding heat. They use a process called “evaporation” to remove the heat that is sitting inside of the unit. But in order to do this, they are installed with very specialized components.  Keep in mind that there are many different kinds that are being used by consumers today. The most common type is a “Freon” unit. Some of the more important parts in them include expansion valves, compressors, coils, and thermostats. Each part plays a significant role in allowing the unit to function and thrive.

How Fridge Freezers Work

In order to keep things cold, a fridge freezer will draw out all existing heat inside of it. In order for this process to take place, the refrigerant in the it (in the form of a gas) will filter through a compressor. This compressor causes it to become very hot and as this heat gas makes its way through the coils, everything begins to cool off.

This causes the gas to be transformed into liquid. Once this occurs, the expansion valve will have gas forced into it. Take note that his valve is relatively small so when the refrigerant runs through it, cold mist comes out.  The mist will run through the coils and eventually turn back into gas form. At this point, the gas is sitting at a ve

ry low temperature of about negative twenty seven degrees.

Finally, it will begin to warm up. This is designed to start removing the heat from inside. Then the heat is sent back into the compressor and the entire process will start all over again. This continues until there is no more heat left inside of the unit.

What Are Internal Thermostats? 

A “thermostat” is basically a small device that is designed to keep it in the right temperature range. This is often the reason why you may hear a fridge freezer turn off and on continually. It also happens to be one of the elements in it that fails the most. As a result, you’ll want to regularly check up on this area and make sure that it is running up to par with the rest of the unit.

Conclusion

Once the fridge freezer is closed, you will never be able to catch the refrigerant with your own eyes. Keep in mind that pure ammonia and Freon are very toxic. They should never be handled by someone who doesn’t have the necessary experience or skill level. IF you have a leak, the best thing you can do is call a repairman.

Early fridges were extremely cumbersome; far from being a neat self-contained unit, such as we have today in the home place, the first commercially available fridges were broken down into their constituent parts and installed in the home in much the same way as an immersion heater, with the food storage compartment in the kitchen, and compressor completely separate- often stored in a basement or storage room.

It goes without saying that the design of these early units was fairly rudimentary, but in terms of function they also lacked the ice or freezer compartment which are commonplace today and which did not arrive until 1923 when Frigidaire, (who still manufacture to this day), introduced the first fully self-contained dual purpose unit. Interestingly, research shows that this particular unit cost more at that time than a model T Ford car! Imagine how much a Model T with a fridge built-in would have cost!!

Fridges improved in design and in features. Automatic defrost capabilities and ice-making components were added bonuses. Refrigerator cost also became more affordable for most families, though there are still luxury machines that are well out the price range of the average middle class family. Yet basic refrigerators can now be purchased for about half their selling prices in the 1920s.

Mass prodcution in the early post-war years saw fridges become available to the masses. By 1955 80% of US homes had a refigerator (in 2005 it was 99.5%). In 1947 a two-door fridge-freezer combination was launched.

In the 1950s, they got big, but now a lot of time and money are spent on design to make fridge-freezers slim, efficient,and good to look at in the kitchen!

Do the old ones last? Here’s one that has!

Refrigeration is the process for drawing heat from substances to lower their temperature, often for purposes of preservation.  Preservation is achieved because reducing the temperature of food slows down the activity of naturally present  bacteria within, so as to delay the contamination process. Refrigeration in its modern, portable form also depends on insulating materials that are thin yet effective. Wherever fresh or frozen food must be stored, processed, transported, or sold, refrigeration is essential; thus appropriate refrigeration machinery has been developed for homes, trains, shops, ships, factories, trucks, and cold-storage plants.

I guess you could say that the first fridge was when an Eskimo put a portion of uneaten fresh seal meat or fish outside of his or her igloo and underneath the snow, possibly packed in with some blocks of ice.

For those with access to ice and snow, such as those living in cold climes and those close to mountains, ice and snow was used. In fact even today you will find cellars or underground areas lines with straw, wood and/or other materials that will retain the cold when food, snow and ice or packed within them. Food would also last longer if placed in a watertight container and then immersed in cold water, such as in a well, lake or stream. A spring of cold water often determined the site of an American settler’s home.

Things took a big step forward when the first patent for mechanical refrigeration was issued  in1834 in Great Britain to the American inventor Jacob Perkins.

Its a common misconception that refigerations systems work by forcing cold air into the unit t chill the food and drink inside. In fact the truth is much the opposite.

Mechanical refrigeration systems are based on the principle that absorption of heat by a fluid (refrigerant) as it changes from a liquid to a gas lowers the temperature of the objects around it. In the compression system, which is employed in electric home refrigerators and commercial installations, a compressor, controlled by a thermostat, exerts pressure on a vaporized refrigerant, forcing it to pass through a condenser, where it loses heat and liquefies. It then moves through the coils of the refrigeration compartment. There it vaporizes, drawing heat from whatever is in the compartment. The refrigerant then passes back to the compressor, and the cycle is repeated. So the food isn’t made cold by lowering the temperature around it, more that the food has its heat drawn from it.

Prior to 1996, the refrigerants used in electric refigerators were chlorofluorocarbons
(CFCs). However, because of increasing scientific evidence that the CFCs are harmful to the ozone layer of the stratosphere, they were banned by international treaty, the Montreal Treaty. Since 1996 Transitional compounds, such as hydrochlorofluorocarbons (HCFCs), which are less harmful to the ozone layer, are to be used in their place until the year 2020. By that time compounds such as the hydrofluorocarbons (HFCs), which are benign to the ozone layer, are expected to have replaced HCFCs.

The first demonstration of artificial refrigeration occurred in 1850, however it was not until the early 1900s, that  fridges became commercially available.

More in Part Two!