Expedition refrigerator vs. cube/half size 120V?

[r2m]

So I’m looking at expedition frigs and see that they cost from a couple of hundred dollars for a small one (read: 2 six packs) to the nearer side of $1,000 for the largest. So I said to myself, “Self, how much would a 120V cube size cost and how much energy would it use?”

So this is what I came up with: About the largest expedition frig I could find was the Waeco CF110 which is 112 quart or about 3.7 ft3 at about $900.00. An average size cube/half size frig has a volume of about 4 ft3 plus and costs under $300.00. Energy consumption is about the same in Watts, except the cube uses 120V, but there are 12V inverters, not a big deal. Okay, I know there is the door issue, the expedition frigs are top loading and the cube is front loading without anything to keep the door shut while driving. I don’t see there being a problem coming up with a simple locking mechanism to keep the door shut especially considering the reduced cost and increased capacity.

Also, I know an inverter costs money too, but there are many ancillary uses for an inverter to justify the cost and anyways I would assume most expedition rigs would already have one. I do.

Okay, so the question here is: Is there any reason one could not use a 120V cube/half size refrigerator instead of the expedition ones? Are there any issues with refrigerators being absolutely level or can they tip at an angle of so many degrees (when they’re off, of course they can be tipped, that’s how they’re moved with dollies). But what about when they’re plugged in and running?

BTY, yes I know that many of the expedition refrigerators can also keep food warm, but I’m referring only to keeping food chilled and/or frozen.

What is the MUD consensus on this?? Is anybody out there a refrigerator guy (gal) or have they tried this?

 

[CardinalFJ60]

my take on this is that the cube fridges are made to sit still on the floor of your home/office/dorm and have doors that open "out". the ARB/Engels etc are designed to handle vibrations, to run at an angle and draw very little current. The lids lock down and are oriented "up" and are durable. I could imagine the door swinging open on rough roads, the contents dumping out and/or when you open it "contents may shift in transit" fall out.

I want to say when a household fridge is delivered, they recommend letting it sit for a while if they were tilted for a while (i could be wrong).

that's just MHO.

 

[Cruiserdrew]

Bad idea.

Normal dorm refrigerators will not survive bouncing over rocks, odd angles and the like. They tend to be cheaply and poorly made. Plus they are not efficient in their power use. While they may have the same power requirement when running, they will run longer, more frequently and with a long duty cycle and consume much more power over time. The front opening means they dump all their cold air every time you open it.

And that's not to mention the inverter losses. Ever notice the average inverter looks like a huge heat sink? That's because it is, and will waste piles of your precious 12v amp hours, just generating heat that is of no use. I could see your combo easily tripling your power needs.

What's your battery situation? If you just have a starting battery, they don't like much discharge, so you'll need a deep cycle to run a fridge. And even a deep cycle can't be discharged more than 50% of capacity without damage. In our little niche of truck based off grid camping you need to be super careful with your 12 v power supply especially if just working of your engine battery.

My advice, bite the bullet, buy a good dedicated 12v fridge, and enjoy. You buy a dorm fridge and try to cobble something together, that's just money pissed away.

Other advice-measure your electrical needs (called loads in electric speak). That will lead you to the battery you need. A 12v fridge needs 30-50 amp hours per day. That's 1/2 the capacity (and thus the max you can use) of a grp27 deep cycle battery. And then you need to charge it back up. If you try and run your fridge off your starting battery, especially some inappropriate fridge with an inverter, bring a friend with a truck and a set of jumper cables or plan on walking.

 

[bluecruiser]

It will fall apart like these guys said. Plus all your stuff would fall out every time you open the door. That would get annoying really quick. The mobile fridges can be brought in the house and plugged in easily into 120v, as well.

 

[e9999]

I tried. Unfortunately, I used an inverter that could not handle the big starting surge. And it fried.

 

[r2m]

Great input guys!! This is the stuff I was hoping to hash out. So maybe this idea is ??
I'd still wouldn't mind hearing if anyone else tried it in the MUD community!

 

[Cruiserdrew]

Great input guys!! This is the stuff I was hoping to hash out. So maybe this idea is ??
I'd still wouldn't mind hearing if anyone else tried it in the MUD community!

Well, if you read E9999's post, he did try it, and it failed. Please try it though, because you will prove it to yourself. Seriously, everyone on a budget considers this course of action, and there's a reason there aren't 500 posts about how great this is.

 

[rusty_tlc]

I tried. Unfortunately, I used an inverter that could not handle the big starting surge. And it fried.

Bingo! An inductive load, like a compressor, has a large initial current surge during start up. So the inverter needs to be able to handle that, now add the conversion loses in that you incur going from DC to AC. If you want the fridge to run when your vehicle is off you need one whompus of an auxiliary battery to store enough amp hours of energy to run over night.

 

[Tigerstripe40]

After figuring in a large inverter, upgrading your charging system, and the batteries necessary to run the fridge, that $900 Waeco fridge is actually a bargain.

What I'd like to see is someone make a free piston Stirling compressor fridge in a 60 liter capacity size. These fridges are VERY efficient.
Coleman sold a stirling fridge that was very reasonable (400 - 500), but it was only 27 liters. They aren't available any more and those people who have them know what they have and aren't willing to sell them (I have one, but I want another).

The Indel B fridges are an interesting option. 50 liter unit is $550 or so and use the low power, high efficiency Danfoss compressor. I guess an Italian company bought a factory in China and then moved their production staff from Italy to China where they are building the refrigerators.

 

[tag3]

Your inverter is running non stop. Even when the fridge is not running.

 

[rusty_tlc]

Your inverter is running non stop. Even when the fridge is not running.

How much current does an inverter draw with no load?

 

[tag3]

How much current does an inverter draw with no load?

It has to at least run the fan to keep it cool. Beyond that it depends on the inverter.

 

[Sligex]

For some of the cheaper inverters, they'll draw ~1A with no load. Some of the more expensive ones are really good about that but they aren't anywhere near as inexpensive (and cost effective) as purchasing a good 12v fridge from the get go.

 

[JCruse]

There's a conversion loss in turning the DC to AC that would make two otherwise equal appliance power requirements, but one using AC and the other DC, use more battery life to run an AC appliance. (Did that make any sense?)

 

[rusty_tlc]

Probably in the neighborhood of 100 - 200 mA for the average mid range converter, based on a random sampling of google results. So roughly two to four times as much as a car stereo system. So if you plan on leaving your car parked for any length of time disconnect the inverter, the best thing is to put it on a switch.

Running a fridge off the inverter is still a bad idea, most won't supply the surge current needed to start the compressor.

 

[Sligex]

Probably in the neighborhood of 100 - 200 mA for the average mid range converter, based on a random sampling of google results. So roughly two to four times as much as a car stereo system. So if you plan on leaving your car parked for any length of time disconnect the inverter, the best thing is to put it on a switch.

Running a fridge off the inverter is still a bad idea, most won't supply the surge current needed to start the compressor.

That sounds abnormally low for an inverter that could start the compressor, just to put it in perspective, your standard Energizer 500 watt inverter probably wouldn't work, as a lot of fridges can draw near 15-20 amps to start, which would be something from 2000-2500 watts. Of course you could find an inverter that supports surge of up to 2000-2500 watts but those are still going to be ridiculously inefficient.

 

[e9999]

I should say that my inverter did not fry the first time I tried it. Only after 3 or 4 times when it obviously did not work and I kept trying. So it's not the poor inverter's fault. It tried hard. Was definitely mine... Guess I tried harder than it did...

 

[r2m]

e9999, sorry to hear about your little inverter that thought it could...

 

[rusty_tlc]

That sounds abnormally low for an inverter that could start the compressor, just to put it in perspective, your standard Energizer 500 watt inverter probably wouldn't work, as a lot of fridges can draw near 15-20 amps to start, which would be something from 2000-2500 watts. Of course you could find an inverter that supports surge of up to 2000-2500 watts but those are still going to be ridiculously inefficient.

"The average mid range inverter" those were the key words in my post.

 

[Josie'sLandCruiser]

Hi all,

I purchased a ~20 year old Norcold brand 12V travel frig back in December specifically for a trip to Moab last month (April.)
I paid $160 for it. I would have loved to buy a new ARB, Engel, etc. 12V travel frig but can't rationalize the ~$700 or so for the amount of use it would get. So I say keep your eye & ears open, you might be able to find a good, used 12V frig.

Good luck!

Alan