Running a Bushman Fridge as a multi-zone

Bridge
I don't own a Bushman fridge but see value in having a couple, maybe three, digital fridge thermometers, sensor on lead, so you can read and verify the temps in each zone created. That way you then know the characteristics of it all. For instance, an Engel will run it's sensor site down to around 10C. below the set temp so there is a "quantity difference of COLD" to be absorbed into the contents. ie, at 4C setting most fridges will cool to around -6C (hysteresis) to provide that ability. Depending on contents absorption rate and loss through walls the reserve of cool ensures the fridge isn't starting and stopping every couple of minutes. You can't test an empty space if investigating, air has no/little thermal mass, so pre cooled bottles of water to around the desired temp should be inserted to each zone to stabilise it all and provide some ability to decide the temps and performance. This all takes time and needs to be done with fridge in similar ambient temp to proposed use, otherwise the equation/ situation is different. It takes a while to get it all in the mind.

Edit
Going from 35L to52L is a big ask and compromise will have to happen. Some fridges use a 12v computer style fan inside to move cool around more evenly so some areas are not starved of cool. 40%more volume will mean much longer run times too.

Hi Briste,
I have that fridge and as Pepper has said it will do as you require but will rely on you adjusting it to achieve what you need.
William

I have the Bushman 35 to 52 Ltr expandable fridge and have only used the 2 zone system.. the thermostat temp below -4...
Pre cool the fridge before loading for your camp..If you can..use 240v..all the better..saves a bit of wear on the AGM's..
So from the floor of the fridge to the first basket..all the frozen stuff..meat etc...then I placed in the bottom of the first basket a layer of Techi Ice sheets..(measured to fit)..then above that level all the foodstuffs and veg..and in the smaller basket..mainly the dairy / small goods.
The only issue I had was with the large bottles I had located at the side..I had to keep an eye on them so they would not freeze..especially the wine.
Anyway it worked reasonably well..when I had finished the frozen foodstuffs..I increased the thermostat to 0 , +1..and had very cold drinks and foodstuffs.
The Bushman portable fridge wasn't really popular when compared to the Engels / Waeco etc that were dominating the camping leisure market at the time..so the Bushman fridge was a steal at $750 with all the baskets/collars it came with when compared to a 45ltr Engel that was about $1100 at the time.
So even today with its flexibility..expandable from 35 to 52ltrs..and nearly at the same price as a 45ltr Engel..it is still good value..
I have had a Bushman since 2007...still going strong..I bought it with Kev 07's GFC money he sent out to people...

Thanks for those replies. Yes, I'm sure that the Bushman works as advertised. One of the remarkable things about researching it is just how happy its owners seem to be, particularly the long term owners. Low power draw and outstanding support being among the reasons.

Peter's use sounds pretty similar to what I had in mind. Peter - what was your thinking about the Techni Ice sheets as a layer between the bottom and middle zones? You're talking about "Techni Ice Reusable Dry Ice Packs / Gel Packs", aren't you? Are you using them as an insulating layer? Or .... ?

I dug around and found the Youtube reviewers who used other materials.This reviewer (at 7:20) mentions insulation foam, and as a user for nine years who has done a reasonably comprehensive review his suggestion has some credibility.

This other reviewer (at 1:40) mentions using plywood, but it's more of a offhand, bored lockdown evening review, and so is less convincing. I'd have more confidence in insulation foam, or perhaps Techni.

RMD's observation that you really need to test and measure in a loaded fridge is valid, but can only be one once I've finally decided and have purchased one.

Bushman power consumption test against a 50 litre Waeco .https://youtu.be/o3V7JAOsIJM

.
Blimey, what a lot of trouble some of you blokes go to in managing your fridges!
Techni Ice panels, plywood, foam etc.
Did you ever get time to admire the sunset?

My old Waeco also had a temperature gradient but we just put the meat in the bottom and butter at the top, with beer in the middle.
Oh, there was a lift-out basket that eased rummaging but that's all.
The potentiometer that set the temperature failed years ago so I modified it to a switch for freezer/chiller operation. It just worked and I just relaxed.