If you are in the market for a 12v fridge for your car or off-road vehicle, there are several points to consider before taking the plunge. I will briefly discuss here some of the more pertinent factors relevant to the purchase of a 12V refrigerator in the hope of making you a more informed buyer.
Compression Or Absorption Technology
The cooling system in nearly all refrigerators utilizes one of two basic technologies: Compression refrigeration or Absorption refrigeration. Each of these systems has its respective advantages and disadvantages for use in a 12 volt cooler.
The major advantage of an absorption refrigerator is that these devices can potentially be powered using gas. If you are considering a 3 way fridge like those used in a caravan for its flexibility (they can be run off 12v DC, mains or LPG) then they will be an Absorption type fridge, as Compression refrigerators cannot run from gas.
One cheap 12v refrigerator good for those on a budget is the Koolatron KWC-4 Coca-Cola Personal 6-Can Mini Fridge. This highly decorative fridge can conveniently cool half a dozen cans of soda to about 40 degrees Fahrenheit below the ambient air temperature.
However, if you plan to run your 12v fridge freezer off DC all the time, rather than using LPG propane, you should definitely lean towards purchasing a compression refrigerator. This type of unit has several advantages absorption units’ lack.
Firstly, while both technologies can be setup to utilize 12v DC, a compression model will use a lot less power than a comparable absorption. This will make a huge difference when you are parked and have the 12 volt fridge freezer powered from your vehicle. An absorption fridge will draw down the car battery quite rapidly, with a well-chosen low amperage compression fridge it may be possible to leave the unit plugged in several hours with minimal impact to your battery charge state.
In fact, a compression 12v fridge can be so energy efficient is it possible to rig yourself up a setup using solar panels to keep it running indefinitely. Given the price of solar power, the fact that this is considered an option speaks volumes to the efficiency of these 12v refrigerators. Particularly noteworthy for their cooling efficiency are the 12v Danfoss compressor fridges.
A second drawback to absorption units is the issue of leveling your portable fridge. They really need to be maintained very close to level in order to work correctly. If you take your vehicle off-road you may well be deliberately seeking out ‘non-level’ terrain. 12v DC Compressor refrigeration shine under these conditions.
Fridge Or Fridge Freezer
If you want a 12v freezer, you should probably again opt for a compressor unit. Absorption 12 volt fridges can usually cool only a certain number of degrees below the ambient temperature and thus makes for a poor 12 volt freezer. With a properly equipped compressor fridge freezer temperatures are possible.
Choosing A Brand
There are several manufactures of 12v fridges suitable for use in vehicles. Norcold, Waeco and Engel are all well regarded model lines, Engel and Waeco refrigeators in particular have a very good reputation for ruggedness and durability. Engels Engel AC/DC Fridge Freezer – Engel MT45F-U1 is a very well regarded 12v fridge freezer that gets rave reviews. The firm Novakool has a line of 12v marine refrigerators intended for use on a boat.
When shopping around you will notice these 12v compressor fridge models are generally significantly more expensive than a similar 12v absorption model; and you may be tempted to purchase a cheaper 12 volt refrigerator freezer absorption model.
However, when buying a 12 volt cooler a budget model may be more trouble than it is worth.
If you are looking for a true 12v fridge intending to use it solely with a 12 Volt power supply, it is almost certainly worth the extra expense for the compressor type of 12 volt refrigerators.