Two fridges... how to run(temps) maybe overkill?

#16
"Two fridges for two people is definite over kill." depends if you are a weekender then yes. but if you want to stay out for extend periods where resupply is a long ways off the more is better. highdesertranger
 
#17
In my trailer I have an enclosed fridge. I made a plenum and employed a thermostat controlled fan to move air over the coils. Keeps the fridge happy even in 100* ambient temperatures :)
 

DaveInDenver

Expedition Leader
#19
"Two fridges for two people is definite over kill." depends if you are a weekender then yes. but if you want to stay out for extend periods where resupply is a long ways off the more is better. highdesertranger
Well, to be honest, having any fridge is a luxury so having two fridges is overkill for anyone. I mean the line between necessity, desire, need/want is blurry. There are people still in this world that have never owned a refrigerator of any kind, so putting even just one in a car and driving around all the time for our own enjoyment is a first world viewpoint.
 
#20
I wouldnt recommend you set your fridge temp any higher than 38. These thermostats operate on an average, typically +/- 2-4 degrees, so setting the set point at 40 could mean it may not start cooling until the temp rises to 42-44. 40 is the upper limit for food safety as it's above 40 that bacteria start to grow exponentially faster.

I know my fridge kicks on about +2 degrees above set point so I typically set mine to 38 to be sure I rarely see above 40.
 

rickc

Adventurer
#21
Sage words DaveInDenver: I should first admit that I just bought a fridge! I think the same "first world viewpoint" thoughts when I read about charging phones, IPads and PCs, adding lighting to an RTT, hot water; the list goes on and on. When I go camping with the kids, all the electronics stay at home. It's a blow up boat, bicycles (sometimes) and most importantly, marshmallows.

I guess marshmallows are first world too!
 
#22
"Two fridges for two people is definite over kill." depends if you are a weekender then yes. but if you want to stay out for extend periods where resupply is a long ways off the more is better. highdesertranger
Agreed. But also agree that this line of logic applies to virtually anything... fuel...water...etc.. based on the guys uses it seems overkill. However he also mentioned he needs good healthy food which is remarkably difficult to come across these days. I think maybe one large fridge? I suppose it depends on the teardrop config etc...
 

e60ral

2016 4Runner Trail w/KDSS
#24
Having 2 fridges where one is a freezer and the other is 40+ degrees seems like a real waste since you don't actually have a fridge. If you are on trips that are long enough that you need a separate fridge and freezer, run one as a freezer and the other as a fridge (<40 degrees). Are you not planning on using meats or things that can spoil? Or are you cooking everything straight from frozen?

A lot of fridges have an area that stays a little warmer for produce or something, My dometic VFX-40 fridge is set to 35 and never gets above 39 degrees and the tray runs about 50ish degrees so I use it for produce and things that don't need to be refrigerated but would melt inside a hot vehicle.

As far as if you need a fridge, my single 40L is good for 2 of us for probably 1 week max with no drinks and about 3-4 days if i keep drinks in there too.

Keep in mind you can also get dual fridge/freezer units that are probably more efficient than having 2 separate units, or at the very least will be more efficient in regards to space
 

Ozrockrat

Expedition Leader
#25
No one mentioned redundancy. We run dual fridges both for the capacity to be away from resupply longer but just as importantly so that we still have a fridge if one takes a dump. A dual zone does not give you that flexibility.

But then again when our truck is all kitted out and full of liquids I still have over 1 ton of payload left. (Actually just under 2 ton).

The intention is that will be living in our truck full time in a few years and after that block of time will be traveling full time. So that has driven our decisions as well.
 
#26
So it seems general consensus is that a fan is probably not all that worth it and just like in the house a full fridge runs better than a empty one.

I have also been curious about the heat removal too. The fridge in the jeep will have plenty of air space to move around, crack a window, open the door, etc.. but I am wondering especialy if running as a freezer my Dometic in the teardrop being under the counter and closed in the rear hatch, it has very limited air space. My teardrop is home built but even the professional built ones, I don't think I've noticed any venting, and if some people running them in a mostly closed off box in the vehicle it must not be to much of a issue?
Fitting a fan in a fridge is one of the worst things you can do, Cans need to be cold, Milk needs to be cold but Dairy products like Cheese, Eggs, Yogurt and Bread need to be kept warmer, Veggie's like to be warmer, Strawberries like to be warmer or they spoil, Banana's don't like the Cold, Fitting a fan will destroy most of your food, People call some fridges Duel Zone, but the fact is a normal fridge/freezer is a "Multi" Zone Item, There is a reason they don't have fans in them and that is so you can store more than one type of food, Forget the Fan and if anything thing Set the Fan up a few inches away so it can blow cold air in to the Vents where the compressor is, Ok.

Hope that helps.

John.
 
#27
I've been running a Dometic CF25 for a few years now but am planning to upsize before our next big multiweek trip this fall. I was originally planning to get the CFX65DZ, but it's too tall to fit under the tonneau of my truck. The CFX75DZ is just too large a footprint. According to Dometic's published specs the CFX40 is the most efficient unit they build, based on AH used. Also according to published specs running the CF25 and the CFX40 simultaneously should run a few hundredths more amps than the CFX65DZ but considerably less than the CFX75DZ.

My major concern is that if both compressors try to run at the same time voltage drop could shut down both fridges. I'll need to do some real life testing to see if I need to run a separate circuit for each fridge.
 
#28
I've been running a Dometic CF25 for a few years now but am planning to upsize before our next big multiweek trip this fall. I was originally planning to get the CFX65DZ, but it's too tall to fit under the tonneau of my truck. The CFX75DZ is just too large a footprint. According to Dometic's published specs the CFX40 is the most efficient unit they build, based on AH used. Also according to published specs running the CF25 and the CFX40 simultaneously should run a few hundredths more amps than the CFX65DZ but considerably less than the CFX75DZ.

My major concern is that if both compressors try to run at the same time voltage drop could shut down both fridges. I'll need to do some real life testing to see if I need to run a separate circuit for each fridge.
If you are worried about the voltage dropping to low to run them then set the battery protector in each fridge to a lower setting that way they can still run if the battery reading reads low, down to 10.6-10.8 volts being the cut off, and when parked you could always add a 100 watt solar panel that would more than help to keep things topped up.
 

e60ral

2016 4Runner Trail w/KDSS
#29
@
Steve_P

I just checked the trending on my battery monitor for my CFX40; when the compressor kicks on my battery voltage drops about 0.25V from the resting voltage, I don't think you should have any issues.

In harsh conditions (interior vehicle temps were almost 130F, fridge less than half full) the compressor runs <10mins every ~45 mins (obviously much less frequent in more optimal conditions)

That was with my fridge set at 35, and per my thermometer the fridge min temp was 33 F and max was 39 F (max vehicle interior is 132 F)

Also I have the insulated cover for the fridge.

I try to park in the shade when possible but it's not always possible for me
 
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#30
@
Steve_P

I just checked the trending on my battery monitor for my CFX40; when the compressor kicks on my battery voltage drops about 0.25V from the resting voltage, I don't think you should have any issues.

In harsh conditions (interior vehicle temps were almost 130F, fridge less than half full) the compressor runs <10mins every ~45 mins (obviously much less frequent in more optimal conditions)
Yeah well that is not too bad 10+45 is a 55 minute duty cycle,

Couple of things to remember is that when we are storing food at home because it is a more of a long term thing we have to set the freezer to -18*c/0*f but because when we are going away for a week or so we can run the freezer's temp at around-10/-12*c which will make the freezer cycle less and if using it as a fridge we can get away with running it at around3 to 5*c which is about 36*f-ish, -18*c/0*f is more of a long term setting.

Keeping the outside of your fridge cool will help a lot and reduce the amount of times it cycles in a 24 hour period, Just because it will work sitting in bright sun light is not a good reason to make it work harder than it needs to which in the long run by protecting the fridge from harsh conditions will promote the fridges working life, We all complain about the cost of these things but do nothing to protect our investments.

hope that helps.
 
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