When selecting a refrigerator for your trailer our priority is being able to use it when boondocking for extended periods of time. To us that means perpetually.
In addition, not running a noisy generator to power it!
That boils things down to either a fridge with an LP/Propane option. Or a high efficiency 12VDC compressor powered fridge you can run efficiently off battery and solar.
We opt to go with a portable unit since we always cook outside. Our long range goal is to cut a compartment door into the side of the trailer. Then have the fridge mounted on a pull out drawer configuration. Making it accessible from the inside or outside.
We also didn’t want the hassle of plumbing LP to an LP unit.
Portability is also something we desired. Though our choice is heavy for its size. It can be thrown into another vehicle. Or easily removed from the trailer should we ever sell the trailer.
To others, you may have other priorities?
The Propane/LP Option
LP models are the way to go, if you don’t want to invest in Solar. Also if you want a permanent inside configuration.
The the LP type will present you with more installation planning and technical problems to deal with.
The “3 way” type gives you the most flexibility. There are the less desirable models, the “2 way”. But they do meet the needs of extended boondocking too.
The “3 way” versions aren’t cheap, but well worth the additional investment. They primarily operate on LP. But when park power is available they work well that way too. Plus the price you are paying for your RV camping site, if including power. Is basically saving you money, while not consuming your LP. The 12VDC side works while you are driving down the road.
These offer permanent type installations that look like your standard home fridge. Though they do require venting.
The 12VDC mode on either the “3 way” or the “2 way” is primarily for use when there is an active 12VDC charging source.
Or very short term time durations, running off your battery. Like stopping for gas or a quick bite to eat.
Even these “3 way/2 way” units are not meant for extended 12VDC run periods, with no external charging source. Such as boondocking or “lot squatting” overnight. Great for driving down the road, when your vehicles charging system is maintaining your battery charge level and maintaining your fridge. But when you are stopped for extended periods and not charging, switch it to LP as soon as possible.
The 12VDC option of those is not so great once you turn your vehicle’s key off. The 12VDC side of things will immediately start consuming the stored energy in your battery. Long term use in 12VDC mode (like hiking or sightseeing) can discharge a single battery. If that battery is your vehicle battery you might not have enough juice to start the engine.
To avoid killing your vehicles starting battery. It is wise to run the fridge off an auxiliary battery. So plan on multiple batteries, battery isolators, and other automatic devices, or your memory, to prevent total battery discharge. Some of these fridge units will auto switch from 12VDC to LP or Park Power 110VAC. Some will shut down once they sense a low battery voltage. Thus potentially sacrificing your food rather than stranding you with a low starting battery.
Also factor in some type of secondary charger (Solar – Park Power 110VAC to 12VDC Converter/Charger – Generator). Your vehicles alternator is not a adequate source to idle at a campsite and recharge batteries as many people think. It can takes hours depending on how many amps you have consumed.
Aside from the RV type “3 way” and “2 way” type of units, there are other options.
The 110VAC Household Fridge or Dorm Fridge off an Inverter & Batteries
(In our opinion the least desirable option for running off solar)
Running a small 110VAC household fridge or dorm fridge off an inverter from batteries or solar is our least attractive method. But we do mention it since some DIYes go this route, or think they are going to go this route.
This option might appear attractive on the surface due to the lower cost fridge. Especially if you do not understand electrical specs or formula’s. They will draw much more power than I prefer. Though I must say the amp ratings of 110VAC Fridge units has been coming down.
These are not ideal for anyone doing any extended boondocking. Though some look at the inverter/battery option as an attractive, less expensive installation. Long term, this configuration may truly not give you the cost savings you see without knowing all the details.
If you invest in solar, and are considering this 110VAC Fridge/Inverter/Battery route, know that you will most likely need double the amount of batteries you would typically use for a high efficiency 12VDC direct fridge unit.
The amp rating at 110VAC needs to be multiplied by 10 to give you the true amp draw off 12V batteries. When converted using an inverter.
The initial cost of additional batteries, and future battery replacement costs, will nearly null out the more expensive initial cost of a high efficiency 12VDC direct unit. Oh….run your batteries too low even once, and you may find out just how expensive this option really is. Especially if you have to replace multiple batteries in one shot because they are damaged.
High efficiency 12V DC Compressor Fridge/Freezers
(Best Choice for use on solar)
This is your best option if you boondock often or are going to the expense of installing any substantial solar.
There are some high efficient 12VDC compressor fridge/freezer units on the market. We list the only a few that make our cut. See them listed below.
Please do not confuse the 12VDC capable Fridge/Freezers with the 12V DC “Coolers”. Or with 12VDC fridge/freezers that consume in excess of 2Ah@12VDC.
There is no comparison. In our opinion the “Cooler” type are just a waste of money for any serious boondocker, or DIYer that wants to dabble in solar, or some type of trailer or van conversion.
To eliminate the “Cooler” type, or perhaps an actual 12VDC fridge/freezer that is low efficiency, check any prospective unit out completely. There are two things to compare. First, the Amp draw (Ah) rating @ 12VDC (NOT @110VAC).
Secondly the cooling capacity or temperature it will cool down to. Take no ones word or recommendation for it until you have reviewed the technical specs on it. The wording is tricky if you don’t understand it. We have run into many people that have no clue what they are talking about.
We only say this hoping to save someone the expense of wasting three or four hundred dollars…..to then come to the same conclusion….they should have spent $800 or $1100 on the first go around.
First you most likely do not want a unit that draws in excess of 2 Ah (amp hours) @12VDC. Sure many will recommend the 4 amp and 6 amp rated units….rated at 12VDC. If you are willing to accept that then go for it. But most running solar any length of time, and depending on it, will never recommend the higher amp drawing units.
If the spec is rated at 110VAC and you intend to run it off an inverter you have to times the 110VAC AMP rating by 10 [a rough but accurate estimate] The tech facts on this configuration become even more confusing.
So a device rated at 1 Ah@110VAC (not talking the 12VDC side of things) for comparison would draw 10Ah off your battery through an inverter. Not 1Ah, as many mistakenly think. Plug a 2Ah@110VAC fridge into an inverter and that baby will be pulling around 20Ah off your batteries. To put that in simple terms, that is lots of battery drain happening in a short time!
Running 110VAC off an inverter is not the efficient way to go…….but yes there are those out there doing it that way. If you haul enough batteries you can cover it.
You don’t want a high amp draw connected to your battery…..unless you want to carry a multiple battery bank with sufficient storage capacity. Then a means to recharge that total usage on a daily basis. Or you have a constant charging source maintaining your battery level. Like a 110VAC to 12VDC Converter-Charger connected to park power, or a generator.
The second thing to look at in a 12VDC fridge/freezer unit, to eliminate the inferior “Cooler” type, is going to the specs again. Some are referred to as thermal electric. If the specs state they cool only to 30°F or 40°F below “ambient temps” we recommend you run away from these units too.
Sure, they have their use for things like a day trip, soft drinks and sandwiches. When the vehicle is mostly running, and charging. Also when the unit is always sitting in an air conditioned vehicle. We are talking sitting in air temperatures in the 70-75°F range, or less.
Yes the “Cooler” types are attractive because of their lower price. The high efficient type will make some people blink and say “no way” when they see the price tag. You certainly get what you pay for when it comes to these superior units.
Expect the high efficiency types (with a danfoss compressor) to start at around $800 for the small ones. The larger ones range into the thousands.
ARB in particular has multiple sizes. We recommend the 82qt model for serious campers. But this is a chest type.
Other manufacturers offer chest types and built in types that look more like a household fridge.
Some types can be installed with a swing out door, rather than the chest type configuration. Yeah you guessed it….they come with a high price tag!
The high efficient type we have, and have tested, for numerous years. Easily maintains -100°F below ambient temps. It has been sitting in a trailer in Las Vegas desert heat, mid summer, yet maintained 0°F, for numerous days. Weeks even. All off solar.
While we use the ARB brand (82 quart model) there are a few other brands out there that meet our specs. We have compared the tech data on many units. We have seen some of the other brands in actual use. Either observing ones we owned, or observed units of other campers we have camped with over the years.
We would really enjoy testing out a variety of these to provide our own opinion on. To date we can only really speak about the ARB.
We have boiled it down to 4 we currently find acceptable. Look for the specs as stated (Amp rating of 2Ah or less@12VDC. Look at the type running a Danfoss compressor or equivalent should technology change. The high efficiency brands, that truly work, seem to be very similar.
Our recommendation is you research and compare the specs. The low amp draw compressor variety. Don’t even consider the “Cooler” types. But technology does change and so may our recommendations.
Here are our recommended brands to research for yourselves:
(High efficiency compressor type)
Isotherm Cruise (some models can be built in with a swing out door)
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