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12 Volt Freezer-Fridges - Do They Bring the Heat?

Written and Permission Granted by Kurt Williams of Cruiser Outfitters

Never heard of one?... What do they do?... Why would I need one?... What do I look for?

Look no further, I'm hoping to answer those questions right here and right now.

12V freezer fridges intended for use in the automobile and marine industries have been around for 20+ years. As with many devices of this nature it was really the Australian and African markets that turned them household items in their respective locales. Brands like Norcold & Engel amongst others have been building these units since the early days and continue to bring innovative models to the market.

What does a portable 12V Fridge-Freezer do? Simple, it plugs into a 12V power source (i.e. the cigarette outlet on your vehicle) and keeps things cold or frozen. Why is that important? Well, if your travels find you days in between ice stops a fridge can be a godsend. Think no more soggy cheese or bloody cooler water. Think about packing for a trip days ahead of time or pulling in from a trip not worrying about unpacking for a few days or months. Heading back out next week? Leave it loaded up and full of food. No more expensive dry ice or daily runs for ice. Besides running on the obvious 12V, most models run on regular household 120V so you can leave them as a beer fridge in the garage or plug your vehicle into shore power at a campground if you'll be staying for awhile. By no means would I call a fridge 'mandatory' equipment for a 4x4 enthusiast--even those that travel for weeks at a time can learn to pack and eat meals that don't require refrigeration. However, nearly every owner is saying things like "best equipment to date" or "wish I would have bought one years ago".

For clarification, my content refers to actual refrigerator units, utilizing a compressor, condenser, expansion valve and evaporator in a vapor-compression refrigeration system. This discussion does not include thermoelectric units. These units are capable of not only cooling but freezing contents, even when ambient temperatures climb into the triple digits. These units will be designed for use not only in a vehicle, but for off-road use where vibration, off camber running conditions, power variances and extreme temperatures could damage or destroy lesser units. For clarity I'll refer to these units as refrigerators or fridges when often in fact they are capable of freezing as well. The units are portable, so while they can be hard mounted or built into mounting or drawer systems, they are designed to be transferred in and out of the vehicle as opposed to hard mounted in an RV, camp trailer or boat galley for example.

Features and Options to Consider: Different models will have different features. I'm not attempting to describe which models have which features, rather discuss why they may be a deal maker or breaker for you. These are listed alphabetically, some may weigh more important to your needs than others.

Battery Protection: Allows the fridge to turn itself off when it reaches a predetermined threshold for your battery voltage. This is most important for those running a single chassis battery, as you would likely sacrifice the cold in your fridge versus the ability to start your vehicle. Some models allow the user to select this threshold as their particular vehicle may allow more liberal power settings whereas others may choose to be more conservative. For example with a dual battery system, one could set the low voltage shut-off at the lowest setting or turn it off altogether.

Cost: As with any purchase this is a very important aspect, but compare the cost relative to the other features of the units and you'll quickly realize that the cheapest fridge isn't always the best option, nor are the more expensive models the 'best bang for the buck'.

Cleaning/Drain Plug: Will the unit be easy to clean in the future? Drinks will spill and condensation will form. Verify the unit is designed and intended to be cleaned. Some units feature removable compartment baskets and drain plugs that allow easy cleaning.

Compressor: Various models of compressors are utilized in the refrigeration process. The majority of the fridges on the market are using Danfoss offerings, however the tried and true Engel is utilizing a Sawafuji swing compressor. So while the Danfoss is a safe bet, don't rule out others. Choose a model featuring a proven compressor that has service and tech support available. Compressors by nature do have wear components so it’s not 'if' but 'when' you could need a replacement part or replacement compressor.

Current draw: This is a major aspect of a true 12V fridge destined for use in a vehicle. A power hungry fridge could drain a battery overnight. These fridges use the latest in compressor, insulation and power management technology to require the lowest draw possible. Depending on the model of fridge and the temperature conditions, a standard auto battery could power it for 3 or more days without compromising the starting capabilities. When utilized with a dual battery system or a dedicated battery for the fridge unit, the system could be adequately powered for a week or more, again depending on both the temperature desired in the actual fridge compartment and the ambient temperatures.

Display: Not all models utilize an actual display unit, however some do feature displays capable of detailing the temperature inside the compartment, target temperature, power saving settings, errors, battery levels, etc. Verify this display will be functional in your particular mounting, visible when needed, etc. Verify the display and associated controls are weather tight particularly in applications that will be exposed to the elements such as mounted in the back of a truck.

Feet & Mounting: Some models utilize the feet to mount into hard mount or slide mounts. Verify the feet are sturdy and will work adequately with your intended setup. If you plan to attach your fridge via the base of the unit, verify it’s sturdy and well constructed.

Handles: Inspect the handles, particularly how they will work in your specific application. Will you be able to reach them while loading the fridge in and out? Do they seem stout enough not only for the empty fridge but for a loaded fridge? Many manufactures rely on the handles for mounting the fridge, verify they are up to the task and appropriately placed.

Insulation: Fridges are still coolers, if they don't hold the cold in and the heat out, they will be grossly inefficient. This becomes more important during a power supply interruption or a planned disconnect, like leaving it back at camp while you head out on the trail for a few hours. The use of transit bags or mounting in a cool, shaded area can vastly help with this but ideally the fridge was designed with good installation in mind.

Lights: Lights up interior compartment for ease of access to goods in the compartment. This may be an unrequired feature when mounted in a lighted area. For power efficiency reasons this light should ideally be automatically be switched when the lid is opened or allow the user to switch it on and off.

Noise & Vibration: Compare the noise and vibration shed by the unit. When mounted in the back of a truck or in a trailer the noise and vibration wouldn't be an issue. However when mounted inside of your vehicle particularly when you sleep inside, noise and vibration could be an issue. Different manufactures use varying methods to control noise and vibration, some isolate the compressor and motor with rubber mounts, others rely on the mounting feet to help knock down undesired sound and shaking.

Power Options - 120V/240VAC & 12V/24VDC: Verify the model you select has the capability to run on the power modes your likely to encounter. Some models can handle all 4 common power schemes, others are set to only handle 120VAC and 12VDC. Some models have the ability to automatically disconnect the 12VDC when the 120VAC is present. This is particularly of interest for those that would use the fridge in a motor home or van conversion in which they have carriage power connected to an outside 120VAC source. Rather than having to disconnect one or the other, they can leave both plugged in and the unit will differentiate between the two power sources.

Size: Refrigerator models range from a six-pack of soda to side by side models that feature two different compartments allowing both a freezing and fridge action. As can be expected the price generally increases with size however the price difference is often minimal compared to the basic cost of the unit, thus if you have the room for the larger size and feel your needs dictate the size then the cost is most likely well spent.

Spares, Accessories & Tech Supports: This is a major aspect for a unit you plan to own for not many years. Event he highest quality units can have issues--broken latches, dented or damaged cases, failed compressors, damaged hinges, etc. As with any other product I feel that the unit is only as good as the tech support and spares available, not just in a year but in 5 or 10 years. Many of the more reputable fridge manufactures still offer parts and service on 20-year-old units. On the flip side some of the more entry-level fridges are virtually 'unserviceable' and customer support and spares availability has been pretty lackluster based on user feedback. Its fair to say 'you often get what you pay for' and a fridge is no different. One other aspect is available accessories. Your needs may change and thus choosing a unit that has a good OEM and aftermarket following is helpful and can offer some innovative features for your unit. For instance for the more popular models you can buy transit bags, slide units, base locks, power setups, baskets, dividers, fitted storage containers, roller kits and even add-on compartment kits that increase the overall volume of the refrigerator. The accessories included with the initial purchase are important as well. Does it come with all the needed power cords? Are they long enough for your needs, heavy duty and adequately sized wire? Does it have a good manual instructing the proper uses of the unit? Does the model have a good dealer network? Can you get a spare part in Mexico or Canada or Africa if needed?

Speeds: Some models feature 'high speed' or 'turbo' modes designed to quickly cool down the fridge compartment. These are most often used where power is not a concern i.e. when plugged in at home before a trip or when shore power is available. Because the current draw is much higher in these accelerated modes this is an option setting that allows the user to revert back to a high efficiency setting when relying solely on precious battery power only.

Thermostat/Temp Controls: Allows user to set desired cabin temperature or range, fridge will automatically cycle on and off to achieve target temperature. Some units achieve temperature settings through a simple arbitrary 1, 2, 3, etc setting while others utilize an actual temperature range or specific temperature. For example some of the popular Engel units offer a simple to use 1-5 setting, which the user must familiarize themselves with, setting #1 on a summer day will vary greatly from setting #2 on a colder winter day. On the other end of the spectrum the newest ARB fridge offering allows the user to specify a select cabin temperature. Simplicity and functionality need to be weighed out by the end user.

Popular Fridge Manufactures:
Bushman Fridge
National Luna

"Mega Fridge Comparo" - Australian 4WD Action #136
"Refrigerator Comparison" - Overland Journal - Summer 2007 Issue
"12V Refrigerator Test" - Overland Journal - Summer 2010 Issue

Fridge Pictures to Wet Your Appetite:

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ARB 50 Qt. Fridge

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Edgestar 43 Qt. Fridge

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Engel MR040

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National Luna 40L Aluminum

Feel free to chime in with your fridge experiences, pictures, mounting solutions, ideas, comments, etc.