How a Propane Refrigerator Works
By: Ben Campbell
The refrigerator has indeed come a long way. It is today so much a part of daily life that one can hardly think of how man used to survive without it. It is because of the refrigerator that you can stock food for weeks and still enjoy the meal you make from it. It is why butcheries do not have to panic when they are unable to sell the day's meat supply on that same day. The propane refrigerator is considered one of the earliest refrigerators. Proof of the relevance of its technology is evidenced by the fact that it has managed to stand the test of time and hold its own to this day in the face of widespread use of electricity-powered refrigerators.
History of propane refrigerators
The use of a propane-like cooling system can be traced to Michael Faraday at the beginning of the 19th Century. Using a mixture of ammonia and silver chloride, he studied the effect of separating the two substances. Referred to as the ammonia cooling system, this simple experiment was the precursor to the modern day propane cooling technique. However, it was not until 1928 that the first propane refrigerator was built by Servel.
How do propane refrigerators work?
In the strictest sense, the process behind the propane refrigerator has not changed much since the days of Michael Faraday. The cooling system is driven by a continuous cycle of heating and cooling involving ammonia, hydrogen and distilled water. The cycle starts by heating the ammonia-water mixture in the generator chamber via a propane flame (this is the reason why the fridge is referred to as a propane refrigerator). Since liquid ammonia would reach its evaporation point faster than the water would, its steam leaves the mixture first with small traces of water vapor. This ammonia rich gas mixture is channeled into a separation compartment. At this point, the ammonia rises upwards towards the condenser section. The structure of the condense section is what makes the ammonia gas cool down into liquid form once again.
The liquid ammonia is then channeled to the evaporation compartment where it mixes with hydrogen gas. This mixture initiates a chemical reaction that rapidly absorbs all heat in the immediate surroundings. It is this reaction that maintains the low temperature inside the fridge. This mixture is then relayed into the absorption chamber where it is mixed with the water that was separated from the ammonia after heating. The ammonia dissolves in the water and this releases the hydrogen. The hydrogen is channeled back to the evaporation compartment as the ammonia-water mixture is channeled back to the generator chamber and the cycle is repeated.
RV versus freestanding
One can categorize propane refrigerators into two: that is, RV (which stands for Recreational Vehicle) propane refrigerators and the freestanding refrigerator. The distinction between the two is in the manner of operation and place used. The RV propane refrigerators use either electricity (whether AC or DC) and/or gas to operate and are often built into or fitted into camping trailers and other similar types of long distance travel vehicles.
One of the main advantages of this type of refrigerator is that one is not restricted to using one power source. You can opt to switch to using either electricity or the propane gas depending on what is most appropriate at that time. The downside of this type of fridge is the fire hazard it presents. The fact that you can have both electricity and gas to power the same device can be quite disconcerting even though manufacturers go to great lengths to ensure safety. The vigorous shaking the refrigerator must endure in the course of travel can move some of its key parts of position and reduce its energy consumption and cooling efficiency.
Freestanding refrigerators on the other hand do not need electric power and run solely on propane. They might not have the same power-source versatility as the RV refrigerators but they rank higher on average when it comes to safety and are thus better suited for use in the home environment.
Application and improvement
One of the main reasons that the propane fridge has managed to remain relevant to this day is the ability to function in the absence of electric power supply. Even with the advances in technology today, the reality is that there are still a number of places that do not have electricity more so in the developing world. However, even among the developed Western countries, there are circumstances where one will not have ready access to power; camp sites, cabins, remote cottages are a few examples of where propane refrigerators can be used. With the propane refrigerator, all one needs is to ensure the water-ammonia mixture is regularly heated. Propane refrigerators can in various sizes to suit different demands.
The efficiency of the propane refrigerator has also steadily improved since the first one was rolled out by Servel. In fact, the level of consumption today is virtually half of what it was then. Today's propane refrigerators are cleaner and more environmentally friendly.
The number of brands and models to choose from is large. Overall, your choice must be determined by your own requirements and the manufacturer's after sales service. Your requirements would include intended use, size of refrigerator required and budget. When it comes to after sales service, it is important that you only go for a product that has an efficient support network close to where you intend to use the refrigerator. Among the most prominent propane refrigerator and freezer brands are Servel, Crystal Cold, Danby, Dometic, Consul, EZ Freeze, Norcold, Blizzard and Frostek.
Ben's Discount Supply has the largest selection of propane and natural gas refrigerators and freezers on the internet.