Norcold Draw vs Isotherm on 12v?

kbdigitiqe · December 2020

We are debating the 3-way vs 2-way config on our new 400 and curious if anyone out there runs the Norcold on 12v and not propane and how hard it drains the battery? We prefer the larger fridge, but we liked the Isotherm in our 2021 320 just fine. We don't want to run two propane tanks, but we do intend to have between 200-350 AH worth of Li batteries.

Thanks!

manyman297 · December 2020

I just placed an order on a 400 and from everything I've read/heard/seen, the 12v (2-way) is superior in every way. I don't have any experience with it but I do have experience with 3-way refrigerators. The one we have (Small Dometic) is terrible and struggles to maintain temps in hotter weather.

Also, I think the 3-way has marginally more usable space than the 2-way but occupies a way larger cubic footprint. Now if the larger 3-way was a 2-way, then we'd be onto something. Otherwise I'm not sure it makes much sense.

4ncar · December 2020

The 3 way is an absorbtion style fridge, and thus is a POWERHOG when running on 12v. The 2 way is a compressor style, and thus sips the power. I do not believe there is anyone, knowingly, using 12v on a 3 way style fridge.

VictoriaP · December 2020

The only advantage to a 3 way is in running on propane if you do significant boondocking in areas where solar is less efficient (up north, or under tree cover). Otherwise, the 12v beats it hands down. I really get wanting the larger fridge capacity of the 3 way because I personally hate having to grocery shop frequently, but I’d buy a 12v cooler as a supplement to the smaller fridge unless you’re mostly camping in rainy, cooler climates. The 3 way does a poor job in hot weather, and doesn’t run even remotely efficiently on 12v.

kbdigitiqe · December 2020

Welp, that absolutely answers it, super helpful thanks all! Fwiw we loved the 12v Isotherm... just wished it was a liiiiitle bit bigger but easily 50% of our camping is in the desert so nope lol!

bergger · December 2020

The 3-way is not really meant to run on 12v. It's just an option if you want some help keeping it cold going from point a to b. And it's mediocre at that. However we chose the 3-way in our 2021 400 and love it. I've had Engle and Dometic 12v fridges and they are awesome and very efficient. Similar to the 2-way in the 400. However I have also had 3-way fridges in other trailers and really like running them off of propane. They get very cold and when running off of hook ups or propane. And when they do run on propane they are way more efficient than the 2 way fridge because it has basically no draw off of your battery! And it sips propane. Plus it is a lot bigger which is important to us. When we truck camp we use a 12v fridge with it's own power source because we have no propane and the fridge is portable, but when we trailer camp we really like the 3-way. Neither beats the other hands down. It just depends on what you prefer. Each has advantages and disadvantages. We like the way.

kbdigitiqe · December 2020

@bergger where do you camp primarily? Can you speak to the performance in hot weather? We camp and drive in the desert a lot and everyone seems to say this particular 3-way is bad in hot weather??

PandK · December 2020

We just bought a 2021 Tab 400 BDL and had to special order it with the 12v fridge. I've been doing some testing and running just the fridge with the Alde and a light to see how long it runs. After 96 hours the state of charge is 60% and that is with almost no solar as it has been raining the whole time.

manyman297 · December 2020

PandK said:

We just bought a 2021 Tab 400 BDL and had to special order it with the 12v fridge. I've been doing some testing and running just the fridge with the Alde and a light to see how long it runs. After 96 hours the state of charge is 60% and that is with almost no solar as it has been raining the whole time.

Wow, that's crazy. I think a lot of people don't realize that these refrigerators are compressor driven. My local dealer has six Boondock 400s on their lot and they all have the 3-way. I understand that it might make sense to have the 3-way if you don't have solar and are boondocking for several days but I think in most people's situations the 2-way makes the most sense.

I even had to explain to one dealer the difference between the refrigerators as he was convinced I was nuts for wanting the smaller fridge.

I think as price comes down on the compressor units and solar becomes more standard equipment we'll see 3-way units phase out.

PandK · December 2020

I'm up here in BC where we don't get much sun at this latitude and with only a bit of sun this would run forever. Total current draw is 120 amps over 96 hours, and thatis with the Alde set at 15C and the outside temp at about 4C

johnfconway · December 2020

A possible option if you want a larger, energy efficient 2-way in the same space as the Norcold 3-way might be to have nuCamp leave the cabinet empty with all of the wiring there. Have dealer (or other) install the Isotherm Freeline 115 in its place... or do it yourself. This frig is a nearly perfect fit width-wise. Leaves some storage space up top. Also leaves room to breath at back.

https://www.indelwebastomarine.com/us/products/fridges-freezers/cruise-marine-refrigerators/large-fridges-115-160-l/freeline-115-elegance/

bergger · December 2020

kbdigitiqe said:

@bergger where do you camp primarily? Can you speak to the performance in hot weather? We camp and drive in the desert a lot and everyone seems to say this particular 3-way is bad in hot weather??

We camp mostly in Colorado, Wyoming and Montana. I can tell you that I've had it in 90+ degree dry weather, high desert, and it has done fine. However, I've never used it in a humid hot climate or in say the Sonoran desert in the middle of summer. So I can't comment on it's performance in those climates. All I can say is that in the areas we camp in it can freeze things in the fridge part if you have it set too high. We also use it mostly for food, with just a few drinks in the door. We keep most of our drinks in a separate cooler in the truck. If we go on a trip longer than 3 days we will also pre-freeze our meat so it will keep the fridge temps down and slowly defrosts over the week.

johnfconway · December 2020

Be really careful of "it works just fine". Unless refrigerator is monitored routinely in seriously hot weather (with an accurate on-shelf bluetooth thermometer), you think its working just fine because 56 degrees feels cool relative to the 98 degree trailer you're sitting in. It's not a good thing unless you are willing to roll the dice on food safety.

We monitored our Norcold 3-way on trips in May, August, Septmber and October. We are in the high (Chihuahuan) desert and also roam into Sonoran. May through September ambient day temperatures 90 to 103 degrees. Night lows in mid to upper 60s. Best Norcold 3-way could do was 56 degrees for several hours during day. Cooled off at night, then right back into the mid to upper 50s by 10:00. In October the days were short enough and ambient temps low enough that the refrigerator on propane could finally keep food safe.

Best delta on absorption refrigerator (on propane) above 80 degrees ambient is 30 - 35 degrees. Food safety max is 41 degrees.

Needless to say, our 3-way is being replaced before May 2021 with Isotherm 2-way. Whether 3-way is for you depends on where you are, where you go and when.

manyman297 · December 2020

johnfconway said:

Be really careful of "it works just fine". Unless refrigerator is monitored routinely in seriously hot weather (with an accurate on-shelf bluetooth thermometer), you think its working just fine because 56 degrees feels cool relative to the 98 degree trailer you're sitting in. It's not a good thing unless you are willing to roll the dice on food safety.
We monitored our Norcold 3-way on trips in May, August, Septmber and October. We are in the high (Chihuahuan) desert and also roam into Sonoran. May through September ambient day temperatures 90 to 103 degrees. Night lows in mid to upper 60s. Best Norcold 3-way could do was 56 degrees for several hours during day. Cooled off at night, then right back into the mid to upper 50s by 10:00. In October the days were short enough and ambient temps low enough that the refrigerator on propane could finally keep food safe.
Best delta on absorption refrigerator (on propane) above 80 degrees ambient is 30 - 35 degrees. Food safety max is 41 degrees.
Needless to say, our 3-way is being replaced before May 2021 with Isotherm 2-way. Whether 3-way is for you depends on where you are, where you go and when.

I’ve had limited experience with a 3-way dometic but my stories are as familiar as yours. It just isn’t reliable and will fluctuate wildly depending on the outside temps. And getting it cold takes at least a day before our trips.

Marceline · December 2020

johnfconway said:

Be really careful of "it works just fine". Unless refrigerator is monitored routinely in seriously hot weather (with an accurate on-shelf bluetooth thermometer), you think its working just fine because 56 degrees feels cool relative to the 98 degree trailer you're sitting in. It's not a good thing unless you are willing to roll the dice on food safety.
We monitored our Norcold 3-way on trips in May, August, Septmber and October. We are in the high (Chihuahuan) desert and also roam into Sonoran. May through September ambient day temperatures 90 to 103 degrees. Night lows in mid to upper 60s. Best Norcold 3-way could do was 56 degrees for several hours during day. Cooled off at night, then right back into the mid to upper 50s by 10:00. In October the days were short enough and ambient temps low enough that the refrigerator on propane could finally keep food safe.
Best delta on absorption refrigerator (on propane) above 80 degrees ambient is 30 - 35 degrees. Food safety max is 41 degrees.
Needless to say, our 3-way is being replaced before May 2021 with Isotherm 2-way. Whether 3-way is for you depends on where you are, where you go and when.

I don't know if this information will be helpful, but a good friend of mine who has an Airstream (and who is an electrician) has added a bunch of exhaust ventilation for his big 3way fridge.

jimcenname · January 2023

johnfconway said:

Be really careful of "it works just fine". Unless refrigerator is monitored routinely in seriously hot weather (with an accurate on-shelf bluetooth thermometer), you think its working just fine because 56 degrees feels cool relative to the 98 degree trailer you're sitting in. It's not a good thing unless you are willing to roll the dice on food safety.
We monitored our Norcold 3-way on trips in May, August, Septmber and October. We are in the high (Chihuahuan) desert and also roam into Sonoran. May through September ambient day temperatures 90 to 103 degrees. Night lows in mid to upper 60s. Best Norcold 3-way could do was 56 degrees for several hours during day. Cooled off at night, then right back into the mid to upper 50s by 10:00. In October the days were short enough and ambient temps low enough that the refrigerator on propane could finally keep food safe.
Best delta on absorption refrigerator (on propane) above 80 degrees ambient is 30 - 35 degrees. Food safety max is 41 degrees.
Needless to say, our 3-way is being replaced before May 2021 with Isotherm 2-way. Whether 3-way is for you depends on where you are, where you go and when.

@johnfcnway how is your new isotherm performing in hot weather? I'm contemplating the same switch.

johnfconway · January 2023

I think I can attach a png to this message. When I tested the Isotherm, the maximum cabin temperature was 96 degrees (no shade) and the undisturbed and loaded refrigerator (to create a cold sink) held at 39 degrees --safe. So a "delta" of 57 degrees. Next day was hotter and cabin temperatures went above 100 degrees. Refrigerator did exceed 41 degrees for a couple of hours.

Best the 3-way could do on propane under ideal conditions was a delta of 25 degrees. So at 85 degrees in cabin, refrigerator was at 60 degrees -- not safe. As a hedge against really hot cabin with the Isotherm, I carry a 200W portable solar panel so we can park in shade. Only carry it when destination forecast is for very hot weather and reasonable probability we can find a dispersed camping spot with shade.

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Norcold Draw vs Isotherm on 12v?

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