Refrigeration with Very Little Power (or No Power)

[Clarity]

If the grid were to go down for 6-8 weeks or longer, gas were to become scarce, propane sold out, and natural gas was not available, what alternatives would you seek during warm months for refrigeration? Yes, you can cure meat. Yes, you can root cellar. But if you must refrigerate, such as to store insulin in addition to food, what approach would you use?

I am intrigued by the small DC solar powered refrigerators, like this one:

Sundanzer Solar-Powered Refrigerator — 8 Cubic Ft., 30in.L x 50in.W x 37in.H | DC-Powered Refrigerators Freezers| Northern Tool + Equipment

Doesn't seem to require much in the way of a solar system. Or would you go with a larger solar system and your regular refrigerator? Or a solar freezer just to make ice (and use a really great cooler). Or something exotic like wood gasification?

You can get by with a lot of things, but a type 1 diabetic must have insulin. We've stored up a supply of some months, just by refilling the prescription as often as we can and using oldest first, but it wouldn't last (be fully effective) for very long without refrigeration. We would extend it's life by getting it deep underground, but that step has it's limits.

Let's hear your ideas!

 

[indyjohn]

I think it's a great idea. Without reading the entire page, I would presume the size is due to the power limits of the solar panels that come with the fridge.

 

[churchmouse]

Well....$1300 for the box....how much for the power pack and panels. That is one darned expensive alternative. I understand if you absolutely have to have refrigeration but this system could bank at well over $2500 when you get it all set up.

 

[scott delaney]

if you have the know how you can build an absorption cooling unit that will work off a small fire. but be very carful

 

[churchmouse]

if you have the know how you can build an absorption cooling unit that will work off a small fire. but be very carful

That would take constant monitoring. I am ammonia certified (or I am just certifiable) and have worked with absorption systems. Way to dangerous for the lay-person to attempt. Hell I would not attempt it.

 

[BehindBlueI's]

What happens if you have two cloudy days in a row? Seems like for the $$$ there would be better alternatives. You could get a chest freezer, pack it with gallon jugs of water, and let them freeze. Empty space in a freezer reduces its efficiency. Put the medicine in the freezer, and then occasionally cycle a generator off and on to allow the freezer to cycle. You could keep it running for a looong time with a few cans of gas stored at the house.

 

[churchmouse]

What happens if you have two cloudy days in a row? Seems like for the $$$ there would be better alternatives. You could get a chest freezer, pack it with gallon jugs of water, and let them freeze. Empty space in a freezer reduces its efficiency. Put the medicine in the freezer, and then occasionally cycle a generator off and on to allow the freezer to cycle. You could keep it running for a looong time with a few cans of gas stored at the house.

Multi-battery inverter back up. Properly used these can supply power for long periods with little generator usage. These can also be tied in with solar or wind. Having the DC fridge would blend in with this very well.

 

[scott delaney]

That would take constant monitoring. I am ammonia certified (or I am just certifiable) and have worked with absorption systems. Way to dangerous for the lay-person to attempt. Hell I would not attempt it.

I would put it together and try it.....or a heat sink unit?

 

[churchmouse]

I would put it together and try it.....or a heat sink unit?

If you had the right materials....everything has to be stainless and capacity's are critical on a small absorber such as you are suggesting. There are other chemicals that go into this mix on a direct absorbor as well.
Heat sinks are an animal unto themselves. I have seen a few in experimental development but never had any real world experience with one.

 

[IndyGunworks]

If you plan it right, and the sky lines up, you can do what they do in Canada... harvest LOTS of ice and keep it in an insulated area.... with enough ice and enough insulation you can keep it cold all summer until the next winter rolls around and you can make more ice.

 

[scott delaney]

If you had the right materials....everything has to be stainless and capacity's are critical on a small absorber such as you are suggesting. There are other chemicals that go into this mix on a direct absorbor as well.
Heat sinks are an animal unto themselves. I have seen a few in experimental development but never had any real world experience with one.

a guy up here in logan is doing some good research and having lots of good luck with heat sinks. he is cooling his bus. with it

 

[churchmouse]

a guy up here in logan is doing some good research and having lots of good luck with heat sinks. he is cooling his bus. with it

It is a unique technology. There is also Lithium Bromide but it requires larger vessels and a lot of heat to move it through the system. Basically you are refrigerating with distilled water and the bromide is the absorbing agent. I have done a lot of this as well.

 

[scott delaney]

It is a unique technology. There is also Lithium Bromide but it requires larger vessels and a lot of heat to move it through the system. Basically you are refrigerating with distilled water and the bromide is the absorbing agent. I have done a lot of this as well.

do you know anyone using this in real world?

 

[churchmouse]

do you know anyone using this in real world?

Lithium Bromide used to be used a lot but it is dying off these days do to expense of initial install and energy consumption. The 4 units I used to deal with regularly have been de-commissioned.

 

[RobbyMaQ]

I don't know enough about this stuff... for something such as insulin, I'd like to think the cost is worth it... especially avergaed out over a period of time.
But whats the shelf life of insulin and meds? my inexperience makes me think the meds will run out as fast as the fuel for refrigeration? Am I wrong, amd these meds can be prepped in large quantities? If so, based on my BIL (boyfriend in law) experiences, the cost of refrigeration pales in comparison to the insulin cost

 

[churchmouse]

The reality in this is that if we hit a really bad SHTF situation there is not much hope for some folks that require medication at that level. All one could do is extend time to the end of the resources. I say this as my wife would be one that time would be limited to the amount of medications we have stock piled. Nothing needs refrigeration which is a plus but once they are gone, well, you know the rest.

 

[Justus]

If the grid were to go down for 6-8 weeks or longer, gas were to become scarce, propane sold out, and natural gas was not available, what alternatives would you seek during warm months for refrigeration? Yes, you can cure meat. Yes, you can root cellar. But if you must refrigerate, such as to store insulin in addition to food, what approach would you use?

My choice would be a small kerosene fridge. Kerosene stores easily.

 

[Spudgunr]

My choice would be a good battery/inverter/generator system and a lot of gas. All parts are easy to come by, well documented, and would be very useful anyway in normal operations. You could run a small inverter off your car, run an extension cord to your battery bank, and then use a 30A charger for recharging, so you could even forgo the generator. My 15cu ft deep freezer uses .67 KWH per day, I suspect a small mini-fridge (2-4 cu ft) with some extra styrofoam insulation glued to the sides would use considerably less than that. I would size the system to be able to run a full size though. How easy do you think fridges would be to come by if the power were out for 6+ weeks? I suspect you would be able to have them just to get the stinking mess out of people's places if people were still even around.

Lets say your fridge will use the exact same amount as my deep freeze. If you only open it once or twice per day it really shouldn't, but lets say it does.
.67kwh *1000 = 670 watts for 1 hour. 670 watts / 12V = 56 amps. So with a 30A charger it'd be just over 2 hours. A car at idle is going to use 1/2 - 1 gallon per hour and you would likely have a LITTLE spare power to run something else small (car inverters don't put out a TON of amps at idle). According to this environmental group saying how bad idling is my ford focus uses .3 gallon per hour, lets round to 1/2 and say you'll use 1 gallon per day. (With an EFFICIENT generator you'd also be able to use a gallon in a couple hours but get a LOT more power out of it, or one of those honda eu's a gallon would go SEVERAL hours with a lot more power). So, gallon per day, times 2 months = 60 gallons, seems perfectly reasonable to store 60 gallons of gas and stabilize and rotate it out.

 

[woowoo2]

RV fridge, runs off propane, cheap and plentiful.

 

[SkinNFluff]

cave system close to me stays a constant 56 degrees inside year round. plus it has fresh water running through it for a constant supply of water. while this option is not something everyone can do it could work for a few.