Fridge Question

[Proudlefty]

Hi, this may have been covered before but search didn't yield anything. I have some options and I'm not sure which one would be wise, could use some advice.

Background:
Just bought a 1988 Falcon 170 on Chevy G20 chasis and it did not come with the stock fridge. The previous owner just bought a dorm style AC fridge and planned to only use it when hooked up to shore power. I want to have a working fridge 24/7 and don't plan to be hooked up so it would need to be powered by my house battery. House battery is an Exide Road Force AGM 200 unless I replace with a better one and I'd like to eventually add 100-200W solar system to charge it.

Option 1: Keep the brand new dorm style fridge (Whirlpool WH27S1E) and plug into an inverter running 24/7. This seems like the least efficient option, the manual for the fridge says it pulls 120V, 60hz, 0.8A, 0.58kW.h/24h. So if my math is right then that's like running a 96W appliance non-stop. That doesn't actually seem that bad compared to many appliances that are in the 400-1000W range but they also aren't being run continuously.

Option 2: There is a used Norcold Model DC-254 12V DC fridge for sale on craigslist not far from me that I supposed I could pick up and learn to wire into my fuse block. I'm not sure what the draw specs are on this fridge but somebody online said it was 20V, 60cycles, 40W. I've heard that 12V DC is pretty much always recommended vs AC + inverter so this seems like a decent option.

Option 3: Spend more for a brand new 3 way fridge so that it could run primarily on propane and only DC sparingly and AC when occasionally plugged in.

So basically all of the options are ahead of me and I'm curious what you all would do if you were in my position. I'm not great with all of the electrical terminology so forgive me if I said something stupid.

 

[peppster66]

we have a 97 dodge Roadtrek, and we use our fridge a lot on our trips, I would definitely go with the 3 way fridge, it makes life on the road so much easier, able to run the fridge in all locations, and if you should buy a new one or a used one really depends on your dollars and sense, are you keeping the van for a long time to get your money out of it, or if its just short term, take a chance on the used one and hope for no problems in the near future, its really a personal choice,,,, good luck,,,,,

 

[hbn7hj]

As you have figured out you don’t have the power to run a compressor fridge. Either upgrade your power system or go with the 3-way.

 

[InterBlog]

It depends on your budget and travel intentions. 3-way fridges do not do well while in motion. Ours used to reach 45 degrees or higher when we were traveling long-haul days during the summer, chugging through propane and ruining all the food. We had two of them and eventually they both stopped working until they were de-installed and flipped upside down in that mysterious practice that nobody seems to understand, but I can attest from direct experience that it worked in our case.

In sum, 3-way fridges were a hot mess in our case. We switched to a Vitrifrigo several years ago and have had perfect operation ever since. But we have 300 watts of solar, and 300 amp hours of lithium battery to accommodate it.

Our two successive 3-way fridges are now stacked on top of each other in the garage to be used during the long power outages we sometimes get with hurricanes. More detailed account here, if you are interested:

REPLACING THE FRIDGE IN AN AIRSTREAM INTERSTATE **AGAIN**!

 

[michaelingp]

So if my math is right then that's like running a 96W appliance non-stop.

Refrigerators don't run non-stop. That's what makes your problem hard to solve. If you're traveling when it's 60 degrees out and the van stays cool, that's one thing, but if you're traveling when it's 90 degrees outside and you park the van in the sun for a few hours, it's going to be 120 degrees inside. The power consumption of the fridge will be totally different.

Years ago we had a 3-way fridge in the Roadtrek. The big benefit was that it would run forever on a tank of propane. The downside was it was a bit finicky about level. We camped for one night on what I thought was pretty level, and the fridge wouldn't work for the rest of the time at that campground (it fixed itself after a long drive). Another time we had a propane leak, so couldn't use propane, so, without solar, so were pretty much without a fridge for the two-weeks left in the trip. It was a manual type so lighting the and extinguishing the flame (for gasoline refueling) and managing the fuel (which of the 3-way's) was a pain.

My sense is that the industry is moving to electric for small vans. One advantage is they cool quickly. My current van has two 12V fridges, and solar panels. Except for parking in the sun for several days, we don't really worry much about managing power for them.

So, my advice would be to get the 12V Norcold and think about solar.

 

[Johnnyfry]

I would definitely stay away from a used ammonia cycle fridge (2 or 3 way) because they are easily abused if run off level and the damage is cumulative and builds up over time. It is difficult to detect the build up of damage so you have no real idea about the working conditioning of the fridge.

 

[GallenH]

In my 97 PW my Dometic 3-way is OEM. 22 years old. No circuit board. Piezo lighter. Once on propane it consumes zero electricity. I did the "mysterious flip" Interblog mentions and it worked for me as well. We don't do long haul and really view the RV as camping. National and state parks in the Southwest.

But when the Dometic goes, I'll bite the bullet, upgrade the electrical to lithium and add roof solar (we have a 100 suitcase).

 

[GallenH]

Oh.....and get a compressor fridge.

 

[rowiebowie]

Oh.....and get a compressor fridge.

And a battery upgrade.

Athough Patrick of New Jersey Outdoor Adventures on youtube stated his replacement Novacool uses only 2.2 amps. If apples to apples they've made significant efficiency improvements over my 8 yr. old Novacool 3100, which draws 3.1 amps when the compressor cycles. When we had two 75 amp lead acids, we could go one night and then we drove every day to recharge our batteries. Now with 200Ahs of Lithium, we can go 2 nights easy, and maybe 3 if we conserve, but we've never actually tired it.

 

[booster]

And a battery upgrade.

Athough Patrick of New Jersey Outdoor Adventures on youtube stated his replacement Novacool uses only 2.2 amps. If apples to apples they've made significant efficiency improvements over my 8 yr. old Novacool 3100, which draws 3.1 amps when the compressor cycles. When we had two 75 amp lead acids, we could go one night and then we drove every day to recharge our batteries. Now with 200Ahs of Lithium, we can go 2 nights easy, and maybe 3 if we conserve, but we've never actually tired it.

Don't put too much faith in the amp rating when on compressor for the frigs, as the speed of the compressor, and thus the amps, change depending on how the manufacturer sets them up initially. The overall efficiency changes with speed, with the most efficient speed for the Danfoss at a bit over the slowest speed. However, that may or may not be the lowest amp draw. I think the manufacturers are playing with the speed to get the lowest amp draw while running, even though it may be less efficient with the btu removed per watt hour used being the critical issue.


You also have to be sure that when you compare frigs, they were tested to the same standardized tests which will give watt hrs used per 24 hours under those conditions.



I doubt there have been huge improvements in the frigs, just manipulation of the settings and data.



I posted all the curves and data on this in a thread a while ago if you feel like going all techie.

 

[mkguitar]

I posted all the curves and data on this in a thread a while ago if you feel like going all techie.

Nice work






still on the 3 way, with wireless thermometer to monitor temps


realistic expectations:



it is marginal at best when in hot climate ( at 100º ambient typical to be 50º on AC parked at home) without Air Conditioning in the van ( 120º+)
Run the AC overnight on LP and will get the fridge down to correct level for start of trip



at temperate climates it is totally fine


It came with a heatswitched fan, I've added 2 more + plus an internal small fan ( all switched) to keep a more constant temp between top and bottom shelves- total current draw when all are running about .7 amps


as with many others
on LP we have no issues making cold
on AC it will make cold slowly
on DC it will slowly loose cold


for that reason on DC I swap blue "freezer packs" from freezer to fridge portions to keep cold


for my older van with a low cap power system this works...it has become a hobby on the road ( turning me into crazy old man)


and I try not to park with the fridge on the "sun side"





mike

 

[Proudlefty]

Hi, this may have been covered before but search didn't yield anything. I have some options and I'm not sure which one would be wise, could use some advice.

Background:
Just bought a 1988 Falcon 170 on Chevy G20 chasis and it did not come with the stock fridge. The previous owner just bought a dorm style AC fridge and planned to only use it when hooked up to shore power. I want to have a working fridge 24/7 and don't plan to be hooked up so it would need to be powered by my house battery. House battery is an Exide Road Force AGM 200 unless I replace with a better one and I'd like to eventually add 100-200W solar system to charge it.

Option 1: Keep the brand new dorm style fridge (Whirlpool WH27S1E) and plug into an inverter running 24/7. This seems like the least efficient option, the manual for the fridge says it pulls 120V, 60hz, 0.8A, 0.58kW.h/24h. So if my math is right then that's like running a 96W appliance non-stop. That doesn't actually seem that bad compared to many appliances that are in the 400-1000W range but they also aren't being run continuously.

Option 2: There is a used Norcold Model DC-254 12V DC fridge for sale on craigslist not far from me that I supposed I could pick up and learn to wire into my fuse block. I'm not sure what the draw specs are on this fridge but somebody online said it was 20V, 60cycles, 40W. I've heard that 12V DC is pretty much always recommended vs AC + inverter so this seems like a decent option.

Option 3: Spend more for a brand new 3 way fridge so that it could run primarily on propane and only DC sparingly and AC when occasionally plugged in.

So basically all of the options are ahead of me and I'm curious what you all would do if you were in my position. I'm not great with all of the electrical terminology so forgive me if I said something stupid.

A bit of an update, I ended up buying the Norcold DC-254 from craigslist for $175. The seller bragged about how little energy it uses and he installed a fan inside to help circulate air and perform better. I just need to figure out how to wire the positive and negative through a switch and to my fuse block. I figured that if my battery system isn't strong enough to power this efficient DC fridge then I'd probably have more problems down the road that would require an upgrade anyway so getting the fridge while I could made sense. Thanks for the advice everybody.

 

[Sehc]

That is a good move. You will like the modern 12 volt compressor fridge. Use the right size awg to avoid extra voltage drop. I use 12 awg from panel fuse to fridge. I hard wired the fridge, eliminated a plug.

 

[Scottie409]

flipping a fridge

In a few posts about 3 way fridges there are a few mentions about flipping the fridge, what is it and for what reason?

 

[Brad1998RD]

Hi, this may have been covered before but search didn't yield anything. I have some options and I'm not sure which one would be wise, could use some advice.

Background:
Just bought a 1988 Falcon 170 on Chevy G20 chasis and it did not come with the stock fridge. The previous owner just bought a dorm style AC fridge and planned to only use it when hooked up to shore power. I want to have a working fridge 24/7 and don't plan to be hooked up so it would need to be powered by my house battery. House battery is an Exide Road Force AGM 200 unless I replace with a better one and I'd like to eventually add 100-200W solar system to charge it.

Option 1: Keep the brand new dorm style fridge (Whirlpool WH27S1E) and plug into an inverter running 24/7. This seems like the least efficient option, the manual for the fridge says it pulls 120V, 60hz, 0.8A, 0.58kW.h/24h. So if my math is right then that's like running a 96W appliance non-stop. That doesn't actually seem that bad compared to many appliances that are in the 400-1000W range but they also aren't being run continuously.

Option 2: There is a used Norcold Model DC-254 12V DC fridge for sale on craigslist not far from me that I supposed I could pick up and learn to wire into my fuse block. I'm not sure what the draw specs are on this fridge but somebody online said it was 20V, 60cycles, 40W. I've heard that 12V DC is pretty much always recommended vs AC + inverter so this seems like a decent option.

Option 3: Spend more for a brand new 3 way fridge so that it could run primarily on propane and only DC sparingly and AC when occasionally plugged in.

So basically all of the options are ahead of me and I'm curious what you all would do if you were in my position. I'm not great with all of the electrical terminology so forgive me if I said something stupid.

I've got an Amana 2.7 cu ft mini fridge on an inverter. It doesn't run constantly so draws very little power. We are usually plugged in but I did leave the fridge on for a weekend while not plugged into shore power. Bare drew the batteries down at all. If I had a couple solar panels I could run indefinitely

 

[mkguitar]

In a few posts about 3 way fridges there are a few mentions about flipping the fridge, what is it and for what reason?

I think you'll find that on you tube


The idea is that the ammonia based media can crystalise and flipping the fridge will dislodge blockage(s) in the tubing...


and possibly result in better operation


IF I were removing my fridge for some reason I would try this...same if it appeared to fail I'd try before replacing




I followed the manual to set igniter gap and clean the stack and my fridge works MUCH better on propane than it did when I bought the old van.


I ( like others) have also added fans at the fins & a very small internal fan to circulate air inside the fridge- camco sells a battery operated internal fan- kinda large and the D cells expensive


mike

 

[InterBlog]

I don't know why fridge-flipping works - I just know that, in our case, it was a bloody miracle in restoring the fridge to full cooling capacity. We tried everything else ahead of that, to no avail.