let's brainstorm: super green modern ice house

So we know there's been a break-through in heating, but I wonder how much thinking has gone towards cooling. I'm thinking of using a combination of northern set, in the ground, typical icehouse/root cellar ideas mixed with evaporative cooling. Perhaps a windmill that has a belt that goes underground and both pumps water up and runs a small fan in the ice house. The water would fall through some sort of straw mesh that would be blown on by the fan.


this is just a quick thought i wondered if anyone would want to add to or comment on. it seems too complex right now. i want it to be simpler. I know that people would tile their floor and poor water on them and open a few windows to let the wind circulate and evaporate the water back in the day. perhaps some kind of ducting to the space with water soaked cob would work. bah. i'll keep thinking.

Using Passive Refrigeration To Stabilize Foundations In Cold Climates

Two-phase thermosyphons are relatively simple devices that transfer heat against gravity. The typical unit is constructed of pipe, closed at both ends, and charged with refrigerant.

The condenser (above ground) portion of the unit can be bare or finned, depending on heat transfer requirements. The evaporator portion of the unit can have almost any configuration as long as slope remains between the evaporator and condenser.

Refrigeration of the subgrade occurs when the condenser temperature is lower than the soil temperature at a depth where the liquid portion of the refrigerant is pooled.

Condensation occurs, initiating evaporation of pooled refrigerant and, hence, subgrade cooling. Condensate returns to the evaporator portion of the pile by gravity and re-evaporates, provided the temperature differentials still exist.

Thermosyphon units operate during the period when the air is colder than the ground, typically during the period from October through April.

http://www.arcticfoundations.com/index.php/news/78-using-passive-refrigeration-to-stabilize-foundations-in-cold-climates

Just pull the air through the icehouse, no need for the evap cooler added on.

Problem is volume. You are talking a HUGE amount of ice. Ice houses are expensive to build unless you find a steal of a deal on insulation.

If you freeze the ground around it you do not need tons of insulation.
That is what the passive evaporators do.

My grandfather had a ice house where he cut ice from a lake and stored it for summer.
The insulation was saw dust. If you have access to the right area sawdust is cheap.
The floor was sand over gravel with a layer of saw dust on the floor.
The sides were log framed and burlap/sand bags of saw dust were stacked on each wall.
The roof was logs, covered in tarp, with several layers of sod over this. It was a living roof with grasses stuff growing from it.

yeah. if i can't think of anything to make it more efficient, i would do a standard icehouse. rock layer, sawdust, ice cut from pond, etc. i would guess you could go to a mill or contact local machine woodworkers or something for sawdust.

i sometimes wonder if there's a perfect size. why do i have to walk in it? maybe it could be underground like the root cellar, but it would be a small door that i opened that had various things in there. perhaps the 10X10X8 or what have you room keeps humidity better than a series of 2x4x2 smaller sized icehouses. maybe the amount of ice packed in there is what keeps it efficient. I would think the more space, the harder to cool, but who knows.

i'm just wanting to look at something old under new light to see if it can be improved.

as for the first suggestion, it would probably need to be april through october, and not something that can not be found locally ie propane, butane, liquid CO2, etc.

10x10x8 is about the minimum side to function as a freezer in my climate. That is with 12" of blue foamboard insulation all around. Amish down the road have one, and I have been talking to them about it as they plan version 2.0. To do it old school with just sawdust, you would want 20x20x20 or bigger and as cube like as you can make it, more core vs. Surface that way. And that is for a freezer equivalent to 2 big chest freezers. That is why the Amish spent $4k on insulation, we do not have enough ice making days to fill an old icehouse.

Freezing the ground has really bad consequences if it isn't supposed to be permafrost.

yes. now lets make it more efficient. in my mind an icehouse should not be above ground.

here are some disconnected things i've remembered:

air cools at it goes through small holes. it goes from high pressure to low pressure and that changes its temp (adiabatic process)

many cultures created fire pistons for increasing pressure to small pieces of dry algae to make a coal to put into kindling. i wonder if a piston has ever been made to repeatedly make low pressure instead of high.

water isn't used in a fridge because it freezes at a temperature you want to get it lower than. 100g of salt in 1 L of solution freezes at 21F. it's not as efficient as freon, but it could probably be used for something.

I guess I am messing something here. This is really just simple thermal dynamics.
It is all about heat transfer.
I store ice I am really storing the ability to absorb energy that transfers into my ice house.
If I had a lake in some areas I am likely to develop a warm layer over a cold layer in summer.
If I take water form the cold layer I can transfer heat to it and cool an areas by heat transfer.

So you really have to goals
One is stopping the transfer of energy into the ice house or slowing the transfer of energy. Such as insulation, radiant heat barriers, etc.
The second is developing sources to absorb energy inside the ice house. Such as cold water from a spring, stored ice, etc.

Also freezing ground works if ground is thaw stable. If not you get expanding and contracting.
However, if you have clay soils you can also get expanding and contracting due to moisture content of the clay soil. Expands when wet and cracks when dry.

If you are thinking of efficiently maintaining a difference in temperature, but skipping insulation, that seems backwards to me.
Insulation is going to most likely give better performance for cost, be cheaper, and last longer than the rest of the whole scheme.

I'd use insulation of some kind around anything I want to keep at a different temperature than the rest of its world.
Especially if I want to do a small-scale version, or a walk-in-walk-out storage, where I have a lot of surface area and empty space compared to my stored thermal inertia.

Here's some ancient refrigeration tech that just fascinated me:

http://misfitsarchitecture.com/2013/02/22/its-not-rocket-science-2-yakhchal/

They also have a good article on night sky radiant cooling, which is the no-power-input (or human-labor-only) version of this heat-transfer idea.
http://misfitsarchitecture.com/2013/03/01/its-not-rocket-science-5-night-sky-radiant-cooling/

We did play with heat tubes recently, and there are some pretty cool things out there - but don't forget that heat naturally flows from hotter to cooler. Keeping something cooler than its surroundings takes energy, and that energy will give off some waste heat, so it's a harder job to keep things cold than to keep them warm.

This "what if" was pretty cool too: http://what-if.xkcd.com/132/

-Erica W

We also got a tip about no-power refrigerators last week: a well-insulated box, with a damp terra-cotta dish on top.
You pour water on the clay dish and evaporation helps it serve as a heat sink, pulling heat away from the contents of the box.
I do the same thing with a damp tea towel on top of my cooler, or a damp paper towel around car snacks, when I can't be bothered finding ice.

There are French butter dishes that use water the same way, and Middle Eastern cooling towers using big evaporative surfaces like porous clay jars or damp fabric (swamp coolers).
If your items-to-be-cooled can tolerate some humidity, evaporation is your friend. Just don't let the moisture condense on them too much, or it delivers that heat right back.

-Erica

Thanks Erica, that was great stuff!
It makes me want to use my solar thermal panels as a cooling source at night in the summer.

If some sort of PAHS idea was added we could call it Passive Annual Ice Storage instead! Create a massive amount of thermal mass underground around your ice house/root cellar and then pump freezing cold air into it all winter. I'm thinking it would be possible to keep an area BELOW freezing, during the summer, WITHOUT electricity. As far as I know though, no one has done this.. Then you wouldn't even need any ice..

I think the idea of PAHS is to have the ground around your living space comfortable temperature for humans, not penguins. You might just have a good point though.

I've thought about an underground space, well insulated, that could be opened to the winter air to freeze many plastic 2L bottles of water over the course of the winter. At the very least you aren't hauling in and packing ice.
This might mitigate excessive moisture as the ice melts. Sounds like the lowest input of labour for a lot of cold storage.

But now what? You'll still have plenty of condensation if you pass humid summer air over the bottles.

Johnmark,

What part of the world is this theoretical project? I ask because if you have the need for cooling, by default you have heat. Back to Permiculture principles. The problem is the solution. Heat is pressure. Pressure is heat. (8th grade physical science class review.) People are missing the boat on Solar Power. Stop trying to convert to electricity at a low efficiency; and then lose more efficiency in driving a motor. If you have heat, replace the electric condenser motor with a heat sink. A large black metal drum will do. Use the refrigerant one would normally use in a frig unit (or go commercial and use an Ammonia based mix), Let the sun heat the gas enclosed in the chamber. Pressure rises. The rest of the system works as normal. Advantage? No electricity. No moving parts. The amazing thing is this is not new technology. This same basic design has been employed in LPG and Propane refrigerators for over 100 years. This just uses the heat of the sun rather than petroleum gas.

That brings up another idea. What about a bio-gas digester to produce methane to run the condenser? Make a sub terranean super insulated spring house, just like grandma's; and reduce the additional 20-30 degrees via a methane fired refrigerator system.

Also Mollison had a brilliant yet elegantly simple way to cool. However it requires some elevation change to get the weight of the water column to work for you. Take a look. Well worth the 7 minutes. Isothermically compressed air!