I have plans for a large, virtually permanent walk-in freezer that uses no power source other than trapping winter's cold. That is, costs nothing to operate, year after year, once built. Plans available free.
I used to go to a family friend's camp in Canada every summer and they used to cut ice off of the lake and store it in a low building with rice husks over it. The ice stayed frozen all summer. I was thinking about doing the same thing except in a small cellar and in the winter, freezing blocks of ice for the cellar and packing it with 2' thick ice walls. Do you think this would work?
I had friends in Alaska who built a very-well-insulated (with a foot of sawdust) ice-house, and in winter they'd pour water on the floor to freeze. When they had a good thick layer of ice, they put a couple feet of sawdust on top of the ice. It kept all summer, and was a good refrigerator (not a freezer, though).
posted 9 years ago
That is a good idea, but the one I like better is based on the 'Icy Ball' system, only using solarenergy as the heat source. This technology is seasonal independant.
Ice with 14% sawdust. Makes the ice melt much slower.
Interesting stuff...developed during WWII with plans on making gigantic pykrete aircraft carriers.
Here's some specs: Comparative properties of materials Mechanical properties Ice Concrete Pykrete Crushing strength [MPa] 3.447 17.24 7.584 Tensile strength [MPa] 1.103 1.724 4.826 Density [kg/m³] 910 2500 980
Once I win the lottery I want to get a boat of sawdust and go out and make artificial iceberg rafts for the polar bears. Wonder if you just did a thin layer spray of pykrete on top of natural sea ice to retard its melting time...
I think that the "wofati freezer" design will allow things to stay frozen all year without any electricity. Of course, it does require that it be built somewhere where the winter temps get well below freezing.
ape99 wrote: Once I win the lottery I want to get a boat of sawdust and go out and make artificial iceberg rafts for the polar bears. Wonder if you just did a thin layer spray of pykrete on top of natural sea ice to retard its melting time...
Hard to say, one the one side it would insulate the ice, on the other, it would absorb more solar radiation because of its colour.... it might melt faster.
We are doing something somewhat similar for our on-farm slaughterhouse and butcher shop - that is to say using winter's cold and thermal mass. But winter alone is not enough to keep the temperature of the freezer low enough all year round. To maintain top quality in the product (meat) we want lower temperatures than we can get by just season cycle swinging.
Additionally we are adding new product all year. Keeping a piece of meat cold is not so hard. But transitioning it from the 103°F of the live animal to the low frozen temperatures (<15°F and ideally <-10°F) is much harder. In fact, it is crossing the freezing point that is the energy problem.
Lastly, we have to do this every week with new product as we slaughter and butcher the next round of pigs. Most of that is kept fresh but anything that is to be frozen has to cross that energy threshold and it is a doozy.
For this reason, in addition to using thermal mass and our cold outside winter air, we'll also be using a compressor. But I do have a plan, we have great micro-hydro potential and can generate our own electricity.