Showing posts with label Permafrost. Show all posts
Showing posts with label Permafrost. Show all posts

Saturday, January 19, 2008

Technology Challenges: Buildings and Housing

Building anything in Antarctica is difficult. The lack of conventional resources such as timber and the remoteness of the continent alone make traditional construction a challenge. This post aims to outline alternative methods of construction that may produce buildings suitable for an Antarctic colony.

Most of the structures built in Antarctica today are not well enough designed to serve a permanent colony. One fundamental flaw is they are built above ground and thus are subject to the forces of the wind and extreme cold. In addition to this most structures leak out heat through windows and doorways further increasing the energy required to heat them.

Building Underground

The easiest way to combat this would be to build structures underground. The permafrost in Antarctica would provide a temperature stable environment year round. I have been unable to locate reliable sub-surface temperate data for Antarctic permafrost at various depths. So, for the following example I will use estimates. If anyone has that temperature data please send it in or post it in the comments section here.

Note the following estimate is given in Fahrenheit.

As a rough example:

If you build below ground and your sub-surface temperate is a stable 25 degrees, and you heat your buildings to 65 degrees you have a constant temperate differential of 40 degrees to maintain. Now, if you build above ground and the outside air temperature is -50 degrees, and you heat your buildings to 65 degrees you have a temperate differential of 115 degrees. It's fairly easy to tell that the 40 degree temperate differential is going to take far less energy to overcome than the 115 degree differential.

Reducing Heat Loss

One of the most important ways to reduce heat loss would be to build extremely well insulted structures. The use of commercially available insulting materials like the Thermalkool radiant barrier (which is paper thin and is rated R52) and other materials like mylar would help greatly. Using these materials in alternating layers with air pockets between it may be possible to build walls rated over R300 that are less than one foot thick. For comparison, the typical American home uses fiberglass insulation that's usually rated R30.

Another way to further reduce heat loss would be to seal the buildings air tight. Preventing air and with it heat from escaping the structure would reduce the energy demands needed to heat it. This of course presents an additional problem of maintaining a constant fresh air supply. For this an air exchanger system combined with a thermal energy recovery system via the use of Stirling engines or another thermal energy conversion technology could be used.

One example of such a system would be to have the cold fresh air intake shaft and the warm air exhaust shaft run parallel to each other with a number of Stirling engines sandwiched in between them. The temperature difference between the cold outside air and the warm air from inside the buildings could be converted back into electrical power this way. Also, a small amount of the waste heat would be transfered though the plates on the Stirling engines providing a small warming effect for the incoming air. This method could also be used with large chambers to effect a single large air mass at one time rather than a shaft system. A chambered system may also allow for multiple stages of thermal energy recovery and air intake heating to occur further increasing the energy efficiency of the system. Of course the larger and more complex the system the more it would cost to build and maintain.

Digging in Antarctica

Permafrost is notoriously difficult to dig through. However, with the use of explosives and modern tunneling techniques, that should be fairly easy to overcome. It will likely be far more expensive to build any sort of tunnel or underground structure in Antarctica compared with the rest of the world, but building any structure in Antarctica is already more costly than elsewhere.

If the underground structures are well insulated as described above, that will enable the surrounding ground to remain frozen. This will serve to increase the stability of the structures and tunnels requiring less bracing and support.

Natural Caves

There are a number of natural caves in Antarctica. There have even been accounts of stranded sailers surviving winters in caves on the sub-Antarctic islands. Many of those caves, especially on the continent have yet to be explored. Many more are buried and hidden under hundreds of feet of ice. It is possible there are caves large enough to build a colony inside them. Unfortunately, the odds of a large natural cave being in an accessible location suitable for a colony are slim to none. This does not mean the exploration of natural caves should be completely ruled out. It may be possible to enlarge a small natural cave to suit a colony. Tunnels between various smaller caves could in theory be dug to connect them. This would largely depend on the area to be colonized and features of the surrounding ground.