How Do Portable Refrigerators Work?

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Sometimes a regular refrigerator just doesn’t offer enough space for the food and beverages you have to store.
Image Credit: Pawel Wewiorski/Moment/GettyImages

Sometimes a regular refrigerator just doesn't offer enough space for the food and beverages you have to store. At other times, you may need another mini fridge or portable fridge, such as when you are traveling, going camping or if you're moving to a new location like a college dorm room. By following a few basic food safety rules and choosing the right unit, you can enjoy the convenience of a second, portable refrigerator.

There are three different types of portable refrigerators: thermoelectric, absorption and compressor. Thermoelectric fridges tend to be much less expensive than the others, but they generally don't have the ability to get as cold as a compressor fridge can.

This is because they use the air temperature of the environment they're in to determine their internal temperature. They're great for bringing on a road trip or short camping getaway where you won't need to keep items very cold for a long period of time.

Absorption fridges are most effective when they run off gas, but can also run off of AC or DC. These refrigerators also aren't temperature controlled and can only go 30 degrees lower than the temperature of the external area around them.

They also have to be on a completely flat surface, otherwise they won't work properly. Typically, these refrigerators are seen in RVs, making them not fully portable — technically. They are, though, a great choice for camping trips and road trips, for when you'll have a power supply. Some might consider these the best fridge for van life.

Compressor fridges are most like the refrigerator you probably have at home, except smaller. These fall in the middle of the range when it comes to power usage. They'll drain more electricity than a thermoelectric fridge and less than an absorption fridge, but they'll also be the coldest option available of the three.

These refrigerators can work even when they aren't level, which means you can bring them anywhere, from camping to bumpy off-roading. They are also temperature controlled, often offering the ability for cold and for freezing. Normally, these fridges are set at 37 degrees Fahrenheit, but you can of course change the temperature as you see fit.

Depending on the external temperature, the internal temperature of your fridge will likely fluctuate by around 6 degrees, higher or lower. Therefore, if the external temperature is quite hot, the refrigerator should be 6 degrees higher than what you have it set at. If the external temperature is really cold, it will tend to be 6 degrees lower than the set temperature.

When to comes to compressor fridges, a pump brings refrigerant fluid into a high-pressure condenser chamber, which is outside of the refrigerator compartment. The fluid then travels into a narrow valve and a low-pressure evaporator, which is inside of the refrigerator compartment. When the fluid is pressurized in the condenser, it heats up, releasing into the air from the outside chamber.

After that, as the fluid flows into the lower pressure evaporator, the temperature turns cold. The fluid cycles between the two, keeping the cold inside while pumping the hot air out into the surrounding area.

Thermoelectric fridges use what is called the Peltier Effect to keep food cold. As an electric current travels between different types of conductors, it heats up, with one end getting hot and the other end getting cold. The cold end of the Peltier is inside of the fridge, keeping the items inside chilled, and the hot end is outside of the fridge, releasing the warmth into the outside environment.

While these thermoelectric fridges are smaller and more compact, they also require more energy to run efficiently.

With an absorption fridge, the cooling process starts with the refrigerant fluid evaporating in a low pressure chamber as it absorbs heat from the interior of the refrigerator. The heat required is low, because it's in a low pressure chamber. The refrigerant, which has now evaporated into a gas, is absorbed by a salt solution, then heated again, which causes the gas to evaporate out of the fridge.

The loss of heat causes the gas to convert back into a liquid to continue supplying the evaporation phase so the process can cycle. As long as the heating coil is heated, this process will continue and will keep the fridge cooled. Absorption refrigerators perform at their best if there is a source of air flow over the heating coils, especially if you're using this portable fridge type in hotter weather.

One of the main benefits of a mini refrigerator is the most obvious one: its portability. They're useful for bringing to a college dorm room where you're not allowed to have a full-sized refrigerator. They can be taken on camping and road trips. And you might even see them in used offices.

They're often very quiet, so they won't disrupt a workday or a student's busy lifestyle. They're useful in that they can comfortably fit in most environments. In the end, you'll find that a portable fridge can fit just about anywhere that you might need it.

If you're traveling with your mini fridge, then you'll likely purchase a camping fridge that requires batteries. This is one of the most energy efficient ways of keeping your fridge running and requires little maintenance on your end. For those that don't run on batteries, you can expect them to absorb a varying amount of energy depending on the size, brand, age, the temperature you choose and whether it manually or automatically defrosts.

Ultimately, the largest benefit of having a portable fridge is its added convenience. At the end of the day, you're making this purchase to meet a need — to have snacks and beverages more easily accessible and in different places. For this need to be met, most portable fridges will deliver.

One of the biggest drawbacks of a portable refrigerator is the fact that it's so small, meaning that it might be difficult to fit certain things, especially larger items, within. Another downside is that you're dependent on a power source if you keep the fridge in a camper van or RV, which means that it could be inconvenient to have to get up and go inside every time you want a drink or snack.

It's also risky to keep a portable fridge in a car or other vehicle, because you have to make sure you don't overextend your auto battery and end up with a fridge full of spoiled food and a car that won't start.

Depending on why you need a portable refrigerator, there are likely a few different types and brands to choose from. For those who are looking to travel with their mini fridge, a thermoelectric fridge would probably be a solid choice. For those who are looking to keep a smaller refrigerator in a new space like a dorm room, garage or office, then a mini fridge with compressor is likely your best option.

A few of the best brands for mini fridges, according to Business Insider, are: Danby, Insignia, Midea, Frigidaire and EdgeStar. These are a good place to start your research before you buy.

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Danielle Smyth is a writer and content marketer from upstate New York. She holds a Master of Science in Publishing from Pace University. She owns her own content marketing agency, Wordsmyth Creative Content Marketing (www.wordsmythcontent.com), and she enjoys writing home and DIY articles and blogs for clients in a variety of related industries. She also runs her own lifestyle blog, Sweet Frivolity (www.sweetfrivolity.com).

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