Adam Grosser: A new vision for refrigeration

I wonder, what refrigerant they use?

The fallacy here is that the lack of refrigeration causes widespread disease because everybody's food goes bad (because it is not in a refrigerator). Sure, vaccines and some other things are an issue, but the basic idea that refrigeration = good and non refrigeration = bad is just more of the same old American Middle Class value system that has pretty much ruined everything.

Food preservation has pretty much always been an issue because it is often hard to time the arrival and amounts of foods to coincide with availability.

The most inefficient option is to just let the food spoil. Less inefficient but still energy and materially intensive are options like drying, salting, radiation with vacuum packing, canning ,or pickling. But for such methods the costs are all up front.

In terms of short-term energy, resources and effort expended refrigeration can be more efficient than other methods. Long term it can often fall behind because once food is dried, salted or otherwise treated the long-term expenditure is minimal. Whereas with refrigeration the outlay is continuous and a simple near linear function of the mechanical efficiency and how much heat gain gets through the insulation.

When I was young, back in the 50's, we (in the UK) had a refrigerator (Electrolux?) that ran on what was little more than a natural gas pilot light, driving an absorption heat exchanger. And it had an ice compartment. I believe they went out of fashion because of ozone layer impact of the evaporant, but I also think nobody tried very hard looking for a substitute since the pump driven versions are so much more profitable for the energy companies, not everybody had gas, and power was very cheap still. or other reasons.

No pump. Very efficient. Don't use CFC's any more. But need continuous if very little heat input. That makes this intermittent solution more applicable.

But it does not change the requirement for stored energy to keep it cold at night, although very modest solar mirror could run it during the day.

GrayGaffer, are you thinking of an ammonia gas refrigerator? They run on a small gas flame and have no moving parts. Very elegant, and could be powered by gasified biomass almost anywhere on the planet.

but the basic idea that refrigeration = good and non refrigeration = bad is just more of the same old American Middle Class value system that has pretty much ruined everything.

I agree to some extent, and I think the "locavore" movement (one experiment with which is described in Barbara Kingsolver's book "Animal, Vegetable, Miracle") addresses this concern in part.

If you're inclined to experiment with various food preservation methods, some more eco-friendly and low-tech than others, there's a great book called "Putting Food By", with Janet Greene as the first author. Older versions are available very cheap at used book stores, and apparently the newest edition includes more high-tech methods. Pickling and canning are pretty labor-intensive, but fun to try if you enjoy food preparation and making huge messes in the kitchen for hours.

I have access to loads of peaches, pears, tomatos, herbs, and peppers most summers, so I bought an inexpensive food dehydrator. Runs on electricity, though, so not the best Luddite solution...but those dried tomatos and peppers sure are fantastic on a homemade pesto and goat cheese pizza.

Blind Squid / Gary
They do make natural gas refrigerators, we have them at The UC reserve in the Mojave.

I've always wondered if there was some way to actually have a fridge generate power, I mean, theoretically you are removing energy from the inside of the unit. Granted we'd need need to have more understanding of how thermal energy can be converted into electricity, and that's way beyond the scope of anything I understand (refrigeration just uses gass laws, correct? PV=nrT?).

CORRECTION:
Blind Squirrel not Blind Squid, hope I didn't offend you!

"Putting Food By", with Janet Greene as the first author.

Wonderful book. I've relied on it during various earlier stages of my own life.

This seems like just another annoying "everyone else was wrong but I got it right, now somebody buy my product" pitch.

Check out
http://en.wikipedia.org/wiki/Icyball

There is nothing inherently wrong with absorption refrigeration systems, they just didn't sell in a market where people have electricity, save a few RV owners.

We had two gas-powered refrigerators at camp on Mooosehead Lake, Maine (no electricity). I first heard about these from my physics professor, George, who had one in the desert. He said "Ahmed, look at this...I light a fire. Come back in an hour and this fire will have made ice."
An hour later, Ahmed came back and saw George take a tray of ice cubes out of the white box. He started to slink away. "What is the matter, Ahmed?"
"George, you are in league with the devil!"

JJ: Unfortunately, refrigeration is a process for which one cannot skip an energy cost, though greater or lesser efficiency is possible.
Any refrigerator is, in effect, a heat pump connected to an insulated storage compartment. Heat pumps essentially function as the reverse of heat engines, using work to produce a temperature differential, instead of using a temperature differential to produce work.(The Carnot cycle and Carnot's theorem are the things to look for if you want the dirty details)
Efforts to push available heat pumps closer to theoretical optimal heat pumps are ongoing, and certainly useful; but the largest and easiest gains are likely to be found in other areas. Better insulation of storage compartments, less wasteful door designs, making sure to cool objects only as much as needed, and being cleverer about exploiting temperature differentials in the environment should be able to reduce significantly the amount of heat we need to pump.
At least in the US, food refrigeration probably isn't at the top of the list in any case. Refrigerated shipping is just a footnote on the general fact that long distance shipping is energy intensive, and domestic refrigeration, while it could definitely use a bunch of engineering improvements, is a decently efficient method of reducing food lost to spoilage. Air conditioning, though, is a pretty massive energy sink; particularly given that most of it is purely optional. I suspect that improvements in refrigeration technology will be largely incremental; but discretionary uses will see a very stiff decline.

phisrow: thanks for pointing out that pesky law of thermodynamics.

I've used gas and kerosene refrigerators quite a bit . They are standard any place that I've worked in Africa where you have a) no electricity and b) kerosene reasonably abundant. This never applied to my main research sites, which for the most part in the Congo were technology free. In South Africa, on the other hand, plenty of ice and some rather fine dining in places.

The kerosene fridges I've used have worked OK, but the first time I saw them in use was in the Semliki Valley where someone had organized an "Earthwatch" which promised excellent food as part of the deal. There was a kerosene refrigerator full of meat, and the fridge would not get cold. The meat smelled worse and worse every day. Eventually the lions and hyenas were fighting for access to our camp, it smelled so good. We had to dump the meat in the bush ... absolutely no other options. The fridges never lost their smell, and they never got cold. What a disaster.

jj: No, I'm not offended, just amused! I May use the name in the future if I become tedious as Blind Squirrel.The problem with ammonia absorption refrigerators is that they don't have a thermostat and never will because of the long lead time between starting the process and the actual cooling effect. You only have a choice of flame settings. As many rv owners have discovered, when the ambient temp rises or falls, the refrigerator will warm up or freeze your food. Also, too high a flame will result in poor cooling as well as too low a flame because the combustion at too high a flame setting is incomplete and unburned fuel passes out the exhaust stack. Greg, I wouldn't be surprised if this isn't what happened to you in the Semliki.

jj: No, I'm not offended, just amused! I May use the name in the future if I become tedious as Blind Squirrel.The problem with ammonia absorption refrigerators is that they don't have a thermostat and never will because of the long lead time between starting the process and the actual cooling effect. You only have a choice of flame settings. As many rv owners have discovered, when the ambient temp rises or falls, the refrigerator will warm up or freeze your food. Also, too high a flame will result in poor cooling as well as too low a flame because the combustion at too high a flame setting is incomplete and unburned fuel passes out the exhaust stack. Greg, I wouldn't be surprised if this isn't what happened to you in the Semliki.

Ever saw the film "Mosquito Coast" (with Harrison Ford)? Making ice to improve someone's life isn't just that easy! he he
But I'd like to have such a refrigerator of yours for my field work. Spending days in hot Rainforest environment requires too much energy or ice to keep food in good condition. I have tried to use Peltier elements, but this involves heavy batteries and isn't efficient enough.
I've searched on the web for the Icyball concept and I'm impressed on it's efficiency. This, combined with a wood gas stove would be perfect, it would enable someone to live for a indefinite time in places where no electricity is available.