Best Fridge/Freezer I can get for my truck? Also go biggest you can afford?

67cj5

Man On a Mission
Just pulled the trigger on the National Luna 52L Legacy Fridge/Freezer. I had kept delaying the decision on the fridge because I was hoping that Engel USA will bring their MTV line in 2020 but once they confirmed that nothing is planned for at least another year, the choice to go with National Luna was a lot easier. The choice b/w the 52 L fridge/freezer and the 50L dual control (same form factor) was not easy and I went back and forth quite a bit. But as @67cj5 and others have said you can really manage the temps by prepping before you leave on your trip. Since we probably don't see ourselves going on any super long trips with our current setup the individually controlled 10L freezer section wasn't as enticing as it would have been had we thought of longer duration trips (or more remote than what we see us doing).
Congrats on the new Fridge, I think you bought the best one, If I was in the market for another Fridge It would be the one you bought, With thoughtful packing and Temp Setting you can use it as a fridge and a freezer at the same time, and having that -30*c Temp setting is great for DEEP Freezing food before you set off and dropping the Temp back to around -10*c that way you can keep stuff in the top you don't want frozen and it will stay that way for weeks/months,

Good Luck and have fun, I am Sooo Jealous, LOL
 

vomhorizon

Active member
So I've been playing around with various settings on the National Luna 52 L the two or so days I've had it. Below is some preliminary data. All testing was done inside the house with an ambient temperature of around 74F so I didn't bother extrapolating any hourly or average draw numbers out of this given the duty cycle was going to be drastically different than what a vehicle based travel application would have entailed. All DC power usage numbers were obtained from my Victron Smart shunt connected to the battery and adjusted for the .1A draw that my set up has at baseline. At all times during the DC measurements, the fridge was never opened and had the Luna cover on it (though it is not an insulating cover) which shouldn't really matter since I was measuring compressor draw as opposed to how often it cycles.

I initially connected the fridge with AC power and let it cool down (about half a dozen bottles of water) to -20C on the display readout. It took about 65 minutes to get there from startup. It took quite a while after that to reach -30 which was the set temperature. It had no problem holding -30C +/- 2C for almost all of the day. I packed it to around 75% capacity and let it warm down to -25C where it was set to run overnight (AC). The temperature was -25C (at the display) when I checked in the morning and while I was observing, fluctuated between -22C and -25C depending upon how the compressor cycled.

Since there is very little power draw data on National Luna's new off-road compressors, I wanted to test DC and connected it to my LiFePO4 battery off cycle (-25C) so that it could re-start once the temperature dropped and kicked the compressor on. So far, I've seen around 2.9A (fluctuating between 2.8 - 3.5 A) when the compressor is running most of the time in regular mode, and around 4.18A (b/w 4.0A - 4.8A) when the turbo mode is engaged and the temperature set to -25C. The manual says that below -11C the fridge follows a two-step logic of a high and medium compressor setting. So I'm assuming the 2.8 - 3.5A variation is the compressor operating in the medium setting while the higher draws (4.0A - 4.8A) are probably indicative of the high setting which is what it defaults to when the turbo-mode is engaged (without stepping down to medium speed). Of course when being operated as a fridge, the system will also default to a "Low" setting (at temperature above -11C which should logically be below that 2.8A - 3.5A draw.

Don't want to directly compare to other 50L fridges out there, but this is what I'm getting based on very early casual testing with the fridge about 75% full and pre-chilled. Since this is my first 12V fridge, don't know if it's good or bad but wanted to put it out there. While most wouldn't probably run it as a freezer and put it on -25C (-13F) when in a vehicle I guess this data might be useful to those like me who are using it as an extra freezer in the house and want to leave it connected to a DC source as a backup in case of a power outage.

EDIT: So upon further reading the manual, it turns out that at the beginning of each cycle, the fridge will run at the low setting for around 3-minutes before ramping up to a medium or high setting which is dependent on whether one has the temp set at below -11C or the turbo mode engaged etc. So in that case, I suppose it is pretty safe to assume that the lower end of my A readings upon cycle start were from it operating in the low setting. Based on this, I think Low (2,000 rpm) is around 2.8-3.0A draw, Medium (2,750 rpm) is around 3.0-3.5A and High (3,500 rpm) is around 4-4.8A. At temps exceeding above -11C (set temperature) the fridge will mostly transition between low and medium after initially working in high to get the temperature down. It is only when temp ranges are in the -11 and -30 degree Celsius range does it consume an excessive amount of high rpm setting.
 
Last edited:

alanymarce

Well-known member
Always try to watch the fast growing travel weight. And watch the bulky size. Use a size who fit your need. The powerusage dont count, because there is not much difference over the weeks.

A size way above 30l seems not to be necessary, too if you are travelling with 4 Persons for an extended tine.
A bit late now, however I agree - we have a 35L Dometic - more than enough for two people - we had an ARB a bit bigger in Africa, however the DOmetic is perfect, takes up no more weight and space than necessary, and has been reliable and efficient.
 

67cj5

Man On a Mission
So I've been playing around with various settings on the National Luna 52 L the two or so days I've had it. Below is some preliminary data. All testing was done inside the house with an ambient temperature of around 74F so I didn't bother extrapolating any hourly or average draw numbers out of this given the duty cycle was going to be drastically different than what a vehicle based travel application would have entailed. All DC power usage numbers were obtained from my Victron Smart shunt connected to the battery and adjusted for the .1A draw that my set up has at baseline. At all times during the DC measurements, the fridge was never opened and had the Luna cover on it (though it is not an insulating cover) which shouldn't really matter since I was measuring compressor draw as opposed to how often it cycles.

I initially connected the fridge with AC power and let it cool down (about half a dozen bottles of water) to -20C on the display readout. It took about 65 minutes to get there from startup. It took quite a while after that to reach -30 which was the set temperature. It had no problem holding -30C +/- 2C for almost all of the day. I packed it to around 75% capacity and let it warm down to -25C where it was set to run overnight (AC). The temperature was -25C (at the display) when I checked in the morning and while I was observing, fluctuated between -22C and -25C depending upon how the compressor cycled.

Since there is very little power draw data on National Luna's new off-road compressors, I wanted to test DC and connected it to my LiFePO4 battery off cycle (-25C) so that it could re-start once the temperature dropped and kicked the compressor on. So far, I've seen around 2.9A (fluctuating between 2.8 - 3.5 A) when the compressor is running most of the time in regular mode, and around 4.18A (b/w 4.0A - 4.8A) when the turbo mode is engaged and the temperature set to -25C. The manual says that below -11C the fridge follows a two-step logic of a high and medium compressor setting. So I'm assuming the 2.8 - 3.5A variation is the compressor operating in the medium setting while the higher draws (4.0A - 4.8A) are probably indicative of the high setting which is what it defaults to when the turbo-mode is engaged (without stepping down to medium speed). Of course when being operated as a fridge, the system will also default to a "Low" setting (at temperature above -11C which should logically be below that 2.8A - 3.5A draw.

Don't want to directly compare to other 50L fridges out there, but this is what I'm getting based on very early casual testing with the fridge about 75% full and pre-chilled. Since this is my first 12V fridge, don't know if it's good or bad but wanted to get put it out there. While most wouldn't probably run it as a freezer and put it on -25C (-13F) when in a vehicle I guess this data might be useful to those like me who are using it as a backup freezer in the house and want to leave it connected to a DC source as a backup in case of a power outage.

Those figure seem normalish, You should be able to set it to -12*c and still have it use less than 1 to 1.2Ah over a 24 hour period and when set to 2 or 3*c it should use as little as 0.5 to 0.6Ah over a 24 hour period,

I know the Foodies say we have to run our freezers at -18*c / 0*f but those are not always needed because those temps are more of a long term thing like 3 to 6 months, But I normally run my 4x4 fridges at -12*c forever and that's all you need unless you are storing Ice Cream which must be kept lower than -15*c or it will melt.

If you had left you NL set to -30 Over time it would of slowly lowered its temp until it got down to -30*c or close to it +/-, All these fridges behave the same , If the contents had already been at -25 to -30*c and you added a few more Items it would of frozen the new items very quickly because the temp of the food that was already in there would speed up the temperature drop, I have seen my ARB's hit -22* and colder and they are only meant to go to -18*c,

What ever you do NEVER touch the metal inside walls of your fridge with wet hands when it is in freezer mode because your hands will stick to it in less than a second and you will be in trouble if no one is there to help, Ok

You got the best fridge on the market so be proud of that and have fun, Don't forget to get back to us when you have had the chance to do some tests in fridge mode,

Good luck and have fun,
 

vomhorizon

Active member
Those figure seem normalish, You should be able to set it to -12*c and still have it use less than 1 to 1.2Ah over a 24 hour period and when set to 2 or 3*c it should use as little as 0.5 to 0.6Ah over a 24 hour period,

I know the Foodies say we have to run our freezers at -18*c / 0*f but those are not always needed because those temps are more of a long term thing like 3 to 6 months, But I normally run my 4x4 fridges at -12*c forever and that's all you need unless you are storing Ice Cream which must be kept lower than -15*c or it will melt.

If you had left you NL set to -30 Over time it would of slowly lowered its temp until it got down to -30*c or close to it +/-, All these fridges behave the same , If the contents had already been at -25 to -30*c and you added a few more Items it would of frozen the new items very quickly because the temp of the food that was already in there would speed up the temperature drop, I have seen my ARB's hit -22* and colder and they are only meant to go to -18*c,

What ever you do NEVER touch the metal inside walls of your fridge with wet hands when it is in freezer mode because your hands will stick to it in less than a second and you will be in trouble if no one is there to help, Ok

You got the best fridge on the market so be proud of that and have fun, Don't forget to get back to us when you have had the chance to do some tests in fridge mode,

Good luck and have fun,

Thanks for the tips. We'll be using it as a freezer for quite a while but might squeeze in a couple of camping trips before the winter sets in so I may get a chance to run it as a fridge in a more realistic scenario. Will report the data here. So far the fridge seems exactly what we were looking for, though probably a tad bigger than we need strictly for camping needs but the utility when not camping more than makes up for that, and since I'm mounting it on a tilt slide the space occupied in the back of my vehicle by a 50L compared to the 40L is practically the same (tilt slide footprint).
 

67cj5

Man On a Mission
Thanks for the tips. We'll be using it as a freezer for quite a while but might squeeze in a couple of camping trips before the winter sets in so I may get a chance to run it as a fridge in a more realistic scenario. Will report the data here. So far the fridge seems exactly what we were looking for, though probably a tad bigger than we need strictly for camping needs but the utility when not camping more than makes up for that, and since I'm mounting it on a tilt slide the space occupied in the back of my vehicle by a 50L compared to the 40L is practically the same (tilt slide footprint).
Yeah I had similar thoughts when I bought my 47L and then I found I was running out of space a few times so I went and bought the ARB 78L, IT's a big fridge and now I find it's too big to move around on ya own unless you have Arms as long as an Oranutan's and weighing in at around 60Lbs when empty has me using the 47L more often than not, So 45/50L is just about perfect,

I also have a 35L and a couple of 18L the 35L is never enough and I just never use it, It seemed like a good Idea at the time.
 

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