Reefers and off grid

[alex trent]

We have had discussion on this in several threads. I thought I would consolidate my experience and thoughts here.  My original comments were based on running a genset a couple of hours once a day to charge batteries and reefer at the same time.  If you don't run genset every day, you have to make some adjustments...I believe with some modifications you can do this on a two day cycle.

1. Chest type is not as convenient, but much more efficient.  I estimate at least factor of two and if you open a lot, more.

2 .Chest freezer is better than a chest reefer. Better insulation and different compressor setup. you can use a separate Johnson Controls device ($30) to get higher temps than the freezer setting. Buy small reefer, but not tiny

3.Keep it a s full as possible. Water jugs work fine. Takes a bit of energy to get them cold initially., but then they are great temperature buffers.

4 Understand that the air and food temperatures are not the same.  There is a big lag. Let reefer slowly go up to 45 air temp and if the food started at 30 degrees (low part of the range) and the food will take another two hours to get to 40. Then when you take the reefer to 28 it will take  the the food another three hours to get to 30, after the reefer air gets to and is maintained at 28.  This is probably the most important part of all of this.  The Johnson controller is reading air temp and you can use a simple food probe to see what happens to the food. Each system needs to be adjusted a bot depending on freezer and food and outside temp, openings, etc.

5. 40 degrees is safe temp for food. Hardly anything freezes to affect quality at 30 degrees.

6. If you go into "town' bring back a 50 lb block of ice...that will do you for three days.

7. My comments in a previous post about a timer really do not apply if you use this system with the Johnson controller. That effectively does it. If you do this with a regular reefer(not a freezer and controller), you use the timer to force it to run longer (set controls on coldest and most will get to 28 degrees) and not go on until air temp is 42...you will have to experiment to find out the time interval.  Most reefer s are set to keep the temp range in a very narrow range..hence they run almost ll the time. Inefficient. Plus, even though the starting load ids just for a brief time it is 800-1,000 watts (3x the running load) so you eat up amps starting up 20 or 30 times a day

This is information I initially garnered while running my bar in a town where the power would die a couple of times a week for from 6 to 12 hours...and once in a while a day.  I was very strict about food quality so I monitored temps closely. In retrospect should have bought a generator.

Right now in my cabin I have a big Colman cooler...25 lbs of ice lasts three days.  We take everything up very cold or frozen.  And in spite of all the chest type mumbo jumbo I wrote above, I will likely buy a small  upright freezer if I can find one).  I'll use a Johnson controller as above and put 25 lbs of ice in once a week. If a reefer, I will stop and start manually. Genset will run 2x a week for two-three hours...charge batteries and pull reefer down to 28. I'll run the reefer an hour a day on other days off the battery. That will be the only big load on the batteries (4 AH a day charging computer and running lights), so should make it on two genset runs a week. This is likely cutting it close on keeping the reefer cold. We shall see. Can always bring up more ice.

[UK4X4]

If your looking at upgrading from cooler 1.1 to refridgerator 2.2

there are many 12V versions, no invertor loss- most use the same compressor- with a batt in the circuit most will run 24/7 off of 1 80watt solar panel

many sizes- most run a danfoss compressor the Engel a fuji swing and the cheaper ones a chinese knockoff

some info from another thread and a link to a testoff

National luna - Southafrican thought to be the best of the best- Danfoss with state of the art control- aluminum or stainless steel cases

Engel- Australian-Thai manufacture- Fufi swing compressor -steel of later model plastic cases - robust good quality units

ARB early versions were rebadged Engels, later they have their own models based off the danfoss compressor

Ironman/Truckfridge Indel B- italian company - again the danfoss compressor

Edgestar/ Norcold, US importers -chinese manufacture- hit and miss on quality from Expedition website

2 other US campanies are importing the above both rebadged.



heres a review of some of the common ones
http://www.expeditionportal.com/resources/equipment-review-and-testing/556-overland-journal-portable-12v-fridge-review.html

http://www.expeditionportal.com/forum/threads/70116-Indel-B-Travel-Box-Fridge-Test-and-Comparison

These are almost all 110v-220V and 12-24V designed in the most for hard offroad travel but equally comfortable keeping beers cool in the garage

I have an Engel 45ltr - 7 years on and off road - when not in the truck it resides behind my bar keeping beers cool.

If I was looking at a cabin fridge maybe the cheaper versions with an extended warrantee would work out fine- seeming compact appliance simply send you a new fridge when you send back the broken ones power lead ! can't beat that warrentee !

My next one if my engel ever dies with be a Nat luna- but I use off orad all over the world so will happily pay extra for ruggedness and smart design - some of their larger fridges do dual areas too - freezer and fridge !

[alex trent]

This is very good info and saves a lot of mucking about with the start and stop routine if it works.  I do not need much capacity .

I need to see if there is anything like this here and there might be as we are slowly getting caught up on this kind of stuff....not a lot of choice, but I am not than picky.

I am in Managua tomorrow and will look Unfortunately they have just really started forcing all th duty stuff here (not sure why) but  this is  40 to 60 % duty. May still be worth it.

[MountainDon]

My 2 cents; to me whatever is used for refrigeration should be dead reliable and not need me to serve it in order to keep my food cold or frozen. It seems to me a lot of folks have "systems" that require too much nursing for my likes. Just something I thought I'd toss in there. Nothing is perfect, but some things are easier for me to live with.

Love the danfoss compressors!!

[alex trent]

It's a trade off.

You can do  bit of work or bump up the system so it just runs like at "home' and requires no attention.  I do not find that the little extra work is mall that big a thing. Not just about saving money on a system, but conserving resources.

The system I described makes no compromise of food safety.