Floating Ice Homes

Question

On an Earth fully covered in water, are floating homes made of ice a practical idea (in arctic latitudes). Ignoring how these houses could be made, would the ice provide enough bouyancy to keep the "home" afloat? Is there a readily available insulation to prevent the ice from thawing inside out that isn't expensive?

I imagined an insulated pre-fab sphere-like structured that is then sprayed with freshwater so that it freezes until a 2 to 3 foot layer of ice had accumulated in which case it would put into the ocean.

Answer 1

Not as described...

Icebergs are frozen fresh water. And presuming that the ocean is roughly as dense as it is now, an iceberg has roughly 1/10th of its total volume above water.

A Spherical House will in this case be mostly underwater, with a small slither above the waterline, which sounds fine...

But that's not the problem, the problem is that it is a spherical house which means that its inherently unstable and will roll. That means that the piece above the water line will fall below the water line.... That is when the ocean will decide to occupy the center of the house.

Ice itself has a weight of about 919 kg/m³. That is pretty heavy, but pure water is fair heavier at 1000 kg/m³, and sea water even more so at around 1025 kg/m³. Carving out enough space in the center to support a workable house, also means carving out enough space for the intruding sea water to overcome the ice's buoyancy.

To solve the capsizing problem means that this house looks far more like a ship.

• Lowering the center of gravity
• passive anti-roll systems such as fins
• active anti-roll systems such as pumped ballast tanks

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Temperature

The next problem is that ice melts, and water freezes.

• When the water (or air) around the iceberg becomes too warm the ice will melt.
• When the surrounding water is too cold, the ice will grow.

When it melts it won't melt evenly, and when it freezes it won't freeze evenly, this will likely unbalance the weight, and eventually cause a capsize.

Not to mention the house might find itself part of an ice-shelf.

And even more insidiously. Water expands when it freezes.

• If the water managed to get close to the house component it will do damage.
• If the water expanded along a fault line it could crack the ice shell, permitting water to explore the new region.

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Making it work.

The truth is that ice is not a very good building material on a planet which permits it to be in any one of the three phases.

You might be able to get away with this on a planet with seas made of another liquid, such as Titan's Ethane/Methane lakes. There Water is always Ice.

Otherwise the best technique would be to build an igloo on the ice sheets/ice bergs themselves. Moving further north and south with the seasons.

Answer 2

There was a project of a ship made from ice&papper. This is quite workable solution. You may want to use hay, wool or some synthetic threads instead of papper for even better results. So yes ice provide more than enough bouyancy to keep small house afloat.

Solid ice block would have only 1/10 above the water, but you don't need to make it solid. Metal wich is most current ships are made from is six times havier than water and it is absolutely not a problem. Since ice is lighter than water you may have quite a thiсk walls for your waterhome.

The only thing you should think about - is a form. Sphere is not approprite. From stability point of view form of the ship is not defined by the material it is made from. So keep to traditional "reverse trapeze" or "half-elipse" hull shapes.

Ice is also a good boatbildiong material since it can "heal" itself: sea water in cracks quickly loose salts consentration and resulting freshwater frezes in a crack and closes it.

The only disadvantige is melting. And even on high lattitudes melting is a problem, since ice is floating in antifreeze. So you would need some active cooling system inside ice hull, to keep temperature of the ice bellow -4 C all the time. Luckely ice has quite a low termal conductivty, but much higher than water and high termal capacity. So it's not that hard to do it, but you will need quite a tight grid of coolant tubes inside ice hull.

You will need to remove about (it greatly depends on hull shape) several watts (5-20) of heat per cubiс meter. Since "carring capacity" of solid ice is about 50kg per cubiс meter (100kg is too much) for, say, "standart cottage" (up to 20t) this means 400 cubic meters of ice (20x20x1 meters ice plate) and 2 kWt of cooling power - about 3-4 kWt of energy consumption. But if we shape that ice in a boat-like hull it would be able carry up to 100t.

For 100 000 t aircarrier-like home (about thousands of people) you will need about 4MWt power to cool it reliably. It's not that much. Boeing 878 produces 1MWt of power for all it's electrical needs during flight. This aircarrier-like home would consume for cooling 10 000 L of disel fuel (less than a tank car) per day, few litters per person . Less than 300$ per person per month.

Answer 3

Yes the ice could provide sufficient buoyancy by a large margin. The potential problem would be ice drift from a polar glacier into the sea followed by a move to warmer latitudes. This could melt the habitat within a few years. Better to build it on a thick layer of ice far from the sea.

If the habitat was sufficiently near to the pole then it would take a very long time to reach the sea. If the world in which this occurred was a bit colder than Earth this time period might be extended almost indefinitely.

In summary have a cold Earth – this would enable a floating habitat to survive for longer or put the habitat near the pole, this would also enable a habitat to survive for longer.