Modern Icebox

[niemand]

OP, I know it’s not your climate, but here’s a tour of David Holmgren’s and Su Dennett’s property:

https://m.youtube.com/watch?v=ss1BjW2kSNs

Have a look at 2:20 where they start talking about the kitchen and their “cool cupboard”.

(They also have an under the counter fridge, but given that Su usually caters for 12 people most days it’s quite amazing they can make do.)

[Dream of Freedom]

So what did you go with?

[theanimal]

Still undecided. I haven't moved in to my place yet so it hasn't been a high priority. At the moment, I am going back and forth between a ~4 cu ft fridge or a Yeti cooler with ice packs. The cooler has a higher upfront cost but it feels kind of silly to use energy/pay for cooling when it is -20 F outside as it is now. The 4 cu ft fridge would cost about $100 used whereas the cooler is $300 new and much harder to find used. I think if I was able to find that brand of cooler for a lower price I'd go with that but at the moment I see it as somewhat of a stalemate. If anyone has any thoughts, they would be more than welcome.

[Alphaville]

energy usage of minifridge is minimal in dollars but i don’t know if you have powerline or solar or something else. probsbly $20/year, maybe less? so 10 years to amortize the price difference of cooler.

also when i had a cooler i spoiled some foods, so consider that cost also. plus the cost of blue ice packs. plus the need to constantly change icepacks. where do you keep/freeze the ice packs?

[theanimal]

Yes, I have a solar setup. Nonetheless, it is a very small power draw and wouldn't affect my system a noticeable amount. The point about spoiled food is very good. That is probably the strongest argument against the cooler. I would keep the icepacks outside for ~7 months during winter. The rest of the year I would have to cool them in my chest freezer if I wanted to deal with that, or do without. Part of me is just attached to the idea of the cooler for simplicity and aesthetic purposes. However, it seems like the mini fridge is likely the best option.

[Alphaville]

do you have a square wave or a sinus wave inverter?

[theanimal]

Sine wave

[Alphaville]

great! sine wave runs everything smoothly

have fun this winter!

eta: would you ever supplement solar with windmill? belt+suspenders.

[theanimal]

thanks! No. A windy day here is when it's blowing like 3-5 mph. There is no wind.

[AxelHeyst]

i used a 35L yeti for over a year in my rig. In winter it was fine: go outside, pick up snow, put snow in cooler, done. It also helped that my rig was really effing cold inside most of the time.

Summer use was a drag. Have to keep the thing half full of block ice, and yeah spoilage is a thing. Sometimes I’d want to just be out in the woods, but had to make a town trip just for ice or risk a serious spoilage event.

if you have a chest freezer, might be doable though. Just rotate ice packs as you said. Not very different from winter use, which i found very tolerable. I’d be tempted to have a go at that strategy, and if you don’t like it sell the cooler and spring for a fridge.

You can get yeti knock-offs for way cheaper (<$100) if you don’t mind buying not-American, that are just as good performance wise. Turns out it’s not rocket science to make an insulated box.

I wound up getting two dc fridges (iceco jp50 and a vl45). I wouldn’t go back to cooler only. The VL45 is loud AF. pro tip: don’t install it 6” from where you lay your head to sleep.

[Lucky C]

Put something that can work as a vapor barrier but not insulator (like a plastic sheet) on the ground. Put a heavily insulated box without a bottom on top of this. I'd look into mineral wool insulation (Owens Corning Thermafiber probably much cheaper than Rockwool brand) since it would be resistance to mold and rodents compared to fiberglass, but rigid foam might be even better. Now you have an airspace that will keep pace with the ground temperature changes much more closely than ambient air temperatures.

Within this space, make another box, or at least floor and preferably walls, with a lot of thermal mass - concrete blocks or containers of water. Now if you put something in the middle of this area you will have even less temperature variation over time. Of course this is now becoming much larger than a typical refrigerated box if you want very slow temperature changes.

In the summer the average temperature may be too high. Add ice, which should last a lot longer than in a typical cooler. Ideally keep is under 40F to keep all types of food out of the "danger zone", but lots of types of fresh produce like warmer temps.

In the winter the average temperature may be too low. Put glass along the southern side to capture thermal heat gain from the sun. Ideally with a sensor to automatically close an insulated shutter over the glass when the sun is down or the box has warmed enough. You now have a passive solar house, but for your food!

[Lucky C]

You could instead have a box attached to your house but thermally isolated from your house, the ground, and the air. Again with a lot of insulation and thermal mass to help hold temperatures steady. Then have vents to outside air and to the house with fans and louvers. With a few temperature sensors and some logic you could blow in outside air when the air temp is in the right direction of the desired temp, or blow in house air when the box is too cold. In theory this could work for a good portion of the year in Alaska when the temperature you want is between the average outdoor air temp and room temperature.

Edit: Not sure where in AK you are but using average Anchorage temperature data, this could work as a fridge (38F max) November through March with minimal supplemental ice for cooling, just during unusually warm spells. October and April would work some of the time, when temperatures stuck to the historical average, but would probably require some more ice and micromanagement to keep foods in the fridge safe temperature range. Otherwise April-May and Sep-Oct (or continuously Sep-May) would at least work pretty well as a fresh produce cooler (around 50F).