Which fridge?

[dreadlocks]

One thing that will need to happen when we buy a powered cooler is a huge change in the way we operate. Right now we have the most minimal electricity needs. Almost no lights at night as we are by a fire until it is time to sleep, often asleep before dark. We can charge the battery at home and go easily 4+ days without need to recharge

Yeah so all that is gonna change, you gonna need at least 200AH of battery capacity to go 4 days w/a light usage fridge.. and then some way to recharge it out in the field..

I need between 400-560 Watt Hours a day to run only my fridge, sealed up in my camper, full of water bottles, nobody opening it or adding anything to it.. this below is my bare minimum base load as my fridge idles in my yard waiting for the next adventure:




Those numbers go up using it, its just sitting right now.. lets start on low end 400Wh, that was a cool day.. 400/13 = 30AH of Energy that Day, the day where it was like 560WH I saw inside the camper at 108F, that day it took 43AH of Energy..

Lets Split the difference, 35AH a day to run my big fridge right now.. 4 days of runtime off a battery would need 140AH, for a lead bank we have to double that because we cant use 100% charge.. so I'd need 280AH of Lead Batteries to go 4 days reliably, just my fridge coasting, no ice maker, no chilling beer, nothing..

I've got 650W of solar and I still carry a genset, because the sun dont always cooperate.. you sure you still want a fridge now? heh

 

[LandCruiserPhil]

While your positions on gear and systems are well thought out and arguments persuasive, here is why I think your solution is not for everyone. You have 83 liters of refrigeration plus an ice maker. I think the fact you have an icemaker shows the importance both of us hold in having ice on hand.

If I were to buy the 40l Engel and put a 1 gallon thermos full of ice in it I would not have much fridge space left. Many of our trips are 2-4 day weekends but we have also spent 30 days from home driving down Baja and 19 days on the road which includes 14 days of sailing. If you think driving into town for ice cream is inconvenient imagine pulling up anchor and sailing for 5 hours to replenish ice just for refrigeration purposes, then the ice, meats and produce you buy on an island has an outrageous markup.

I am not sure your arguments against a DZ hold up. If you use it as a dual zone you lose capacity to the divider. If you have the freezer section set to -5 (which apparently is a possibility) sure you will be using a ton of power but if you set it the whole unit to fridge temp does it cost any extra in power compared to a single zone?

The way my current analysis is buying a DZ gives me the potential to make ice in a remote location if power allows it and it is needed. If I remove the divider and set the temp to fridge the DZ only cost to the higher end unit is a few hundred bucks.

My 95DZ does not have a divider and has separate t-stats. Best I can tell it runs a single larger compressor(based on power consumption) and switches the coolant lines to control temps. So yes it can use more power but it is also more efficient in some ways. Also with a true DZ you can only use 1/2 of the fridge if not needed.

 

[jadmt]

On my arb50 I set it to 34f and I can throw in a bag of ice for mixed drinks and the ice will not melt. I like my beer and whiskey and cokes.

 

[Photobug]

I'm pretty sure Engels wont get below 0F, is Baja less than 86 degrees? If so mebe it is possible to hit -5, otherwise where you get your data from?

Here is a video testing the Engel 40 against a built in RV fridge. I have read elsewhere it can get down to -5 or show an 80 degree difference from ambient temps. All in all very impressive performance shown in the video.

 

[dreadlocks]

Yeah but its 110 degrees in Baja today, how hot is it inside a vehicle.. if you get your vehicle to ambient, with an 80 degree difference.. its 30F inside your "Freezer", trying to make ice in a 30F freezer, would take days.. not hours.

If you crank the temp to lowest, and are in a very hot environment.. the duty cycle of the compressor goes way up, instead of coming on every 20 mins for 5mins, it'll run solid most of the time trying to extract heat.. there's a big difference between maintaining temps and actually chilling/freezing things power wise, packing for a weekend and only taking things out is one thing.. restocking it with beer every few days and getting those chilled alone will increase energy needs dramatically, adding items to be frozen darn near makes fridges unreasonable with the power requirements.

 

[dreadlocks]

My 95DZ does not have a divider and has separate t-stats. Best I can tell it runs a single larger compressor(based on power consumption) and switches the coolant lines to control temps. So yes it can use more power but it is also more efficient in some ways. Also with a true DZ you can only use 1/2 of the fridge if not needed.

Thats cool if thats how that actually works, pretty rare for a DZ to operate that way... I googled it tho, it has a divider now it seems.. but given the size and true dual temp controlled chambers thats okay if you really need that kinda flexibility.. however I check its specs and find its DC power needs are 10A!!!! My MT80 is max 3.6A, that probably has multiple compressors or something.. power usage is still fairly reasonable, 43AH/day @ 39F internal, however My MT80 is using ~30AH/day @ 30F internal at ~90F ambient so its still got the energy advantage.

When we go out for weekends and dont need the full capacity, we simply pack the fridge up with frozen water bottles or more beer.. actually helps reduce power needs having a permanent thermal mass in them.. so I doubt being able to shut down half a fridge would really provide any gains over half a fridge of ice packs that would reduce energy needs almost nothing.. and now you have some backup very cold water incase anyone gets heat stroke.. On longer outings half the fridge is pre-frozen meats like slabs of bacon and bags of ground beef, they stay frozen on the bottom and also help reduce energy needs.. if that was isolated away from my drinks it'd take more energy to maintain my drinks temps.

 

[FJR Colorado]

Best way to do it if you want fridge and freezer is get 2x classic Engels. That seems to be the one fridge that can freeze anything solid.

 

[Photobug]

My 95DZ does not have a divider and has separate t-stats. Best I can tell it runs a single larger compressor(based on power consumption) and switches the coolant lines to control temps. So yes it can use more power but it is also more efficient in some ways. Also with a true DZ you can only use 1/2 of the fridge if not needed.

Do you have the Dometic? I am leaning towards it because of footprint. Unless I completely redesign my truck I need a lower height than most cooler offer.

 

[LandCruiserPhil]

Thats cool if thats how that actually works, pretty rare for a DZ to operate that way... I googled it tho, it has a divider now it seems.. but given the size and true dual temp controlled chambers thats okay if you really need that kinda flexibility.. however I check its specs and find its DC power needs are 10A!!!! My MT80 is max 3.6A, that probably has multiple compressors or something.. power usage is still fairly reasonable, 43AH/day @ 39F internal, however My MT80 is using ~30AH/day @ 30F internal at ~90F ambient so its still got the energy advantage.

When we go out for weekends and dont need the full capacity, we simply pack the fridge up with frozen water bottles or more beer.. actually helps reduce power needs having a permanent thermal mass in them.. so I doubt being able to shut down half a fridge would really provide any gains over half a fridge of ice packs that would reduce energy needs almost nothing.. and now you have some backup very cold water incase anyone gets heat stroke.. On longer outings half the fridge is pre-frozen meats like slabs of bacon and bags of ground beef, they stay frozen on the bottom and also help reduce energy needs.. if that was isolated away from my drinks it'd take more energy to maintain my drinks temps.

Im sure you know a lot can affect the power consumption and because one draw X and the other draw is lower that does not always mean less need for power. That said I have 4 fridges and all can make it overnight with only group 27 90AH lead battery. Right now its still 100° at midnight with a low of 86° very hard on any freezer fridge.

Side note - When testing the 95DZ I never saw running amps above 7amps using also a Victron solar controller.

 

[LandCruiserPhil]

Do you have the Dometic? I am leaning towards it because of footprint. Unless I completely redesign my truck I need a lower height than most cooler offer.

Yes my 95DZ is a Dometic. Your are correct lower than most fridges a lot smaller. Nice fridge with a lot of options to help tailor to fit your needs. The wifi gives you full control and info. The handles can be removed to reduce size to under 36". One thing I dont like is you need space at the back of the fridge to open the lids.
Dont know where you are and if you would be interested in used but Im thinking of selling my 95DZ with a Dometic slide and insulation cover.

 

[dreadlocks]

yeah the bigger ones you can pack with more stuff and get them really low power idling along with so much cold and frozen stuff, or you can fill it up with room temp beer and they can skyrocket because it has so much more to cool down, or leave it empty with air to cool.. its hugely variable, I was using the power draw as more of a hint that it used two compressors, ~7A would be about 2x what I would see.. there's only like 2 different compressors used on these style fridges and they both draw about the same power, so performance between brands usually comes down to insulation and things.. those brands with super thick insulation and less storage room are able to coast sipping on less power, but to add heat in and cool it down refilling the fridge the'll end up drawing pretty close to the rest as it pumps that heat out.

A dual compressor dual zone fridge would be more efficient naturally than 2 individual fridges, in both space and because they have better insulation/thermal aspects with another cold box immediately adjacent.

 

[Photobug]

Yeah but its 110 degrees in Baja today, how hot is it inside a vehicle.. if you get your vehicle to ambient, with an 80 degree difference.. its 30F inside your "Freezer", trying to make ice in a 30F freezer, would take days.. not hours.

I have no intention of trying to make ice in hell or in Baja in summer. I was in Baja last November, that was plenty hot for me. I have no interest in traveling anywhere it is supposed to be in the 90s or above. I would like the ability to make ice but the quality of my trip is not dependent on it. If I got a dual zone, I would likely run the freezer at 20f hoping that would keep icecream hard and produce ice over a 20 hour period. to be ready for the next evening's happy hour.

 

[dreadlocks]

If I got a dual zone, I would likely run the freezer at 20f hoping that would keep icecream hard and produce ice over a 20 hour period. to be ready for the next evening's happy hour.

Okay, thats fine.. however, be prepared to lift a rather heavy energy need for this capability.. sounds like your coming from basically nothing energy usage wise, right to making a pound of ice a day.. how much money and room you got for batteries and solar panels? You sound like you need indefinite running right? ability to never need shore power to keep power on.

 

[dreadlocks]

I produce ice with this on my house inverter: https://www.amazon.com/gp/product/B07H7SGQ52/

Takes about 10A of load and makes enough ice to chill a mixed drink in less than 10mins, in comparison its extremely efficient and ran on demand when the battery is full and I've got >150W of excess solar so it dont even hit my battery needs.. its much smaller than a 2nd fridge/freezer, any extra ice we make in the day goes in the thermos to be used at night, dont even need to go into the fridge unless it needs to keep for days.

 

[LandCruiserPhil]

I produce ice with this on my house inverter: https://www.amazon.com/gp/product/B07H7SGQ52/

Takes about 10A of load and makes enough ice to chill a mixed drink in less than 10mins, in comparison its extremely efficient and ran on demand when the battery is full and I've got >150W of excess solar so it dont even hit my battery needs.. its much smaller than a 2nd fridge/freezer, any extra ice we make in the day goes in the thermos to be used at night, dont even need to go into the fridge unless it needs to keep for days.

I must admit I was just looking at this option. Any reason you picked the Vremi model you picked as they all seem similar in performance?