Passive Solar and Light In Earth-Sheltered Housing

I've been reading a lot lately about this earth-sheltered housing phenomenon, but some people still remain skeptical about the potential "basement-like" feeling of living partially underground. This is understandable, considering most of the homes are enclosed on 3 sides. If you are lucky enough to own land on a south facing slope, however, or if you have an area where you are able to pick the direction of your home, then you can utilize passive solar energy and avoid that "basement" feeling

If the house is built to properly maximize its solar potential, then it will have an elongated layout, with all bedrooms and living areas to the front of the home where the windows are located, and all of the bathrooms, storage areas, and utility rooms toward the rear of the home because no windows are necessary. In south facing homes this allows the maximum amount of light to penetrate the home, even in the middle of winter. This light also has the benefit of warming the home in the winter, with the assistance of an absorber and a thermal mass to hold the heat inside the home. In the summer this is controlled by an overhanging roof, as discussed previously.

Back to the original topic; lighting. These homes can actually have more light than a conventional home without any lighting fixtures. Many of these houses are constructed with domed or cathedral ceilings and light colored paint. This allows the light that enters the room to bounce off all of the curved and angled surfaces, scattering the light and illuminating the would-be dark space. The homes may also be built with skylights which allow sunlight access to the rear regions of the home. A fairly large example of this can be seem here.

Earth-sheltered homes therefore utilize solar energy in two major ways which cut down on energy consumption. They use passive solar energy to heat the home in the winter. This is accomplished through direct gain through the windows, and through indirect gain from the earth around the home. The summer sun warms up the earth around the home and slowly releases it into the home as the winter wears on. The light from the sun is also used to light the house which prevents the need for lighting in the rooms with windows during the day.

We need to begin to use more of these qualities from the earth and sun which are all renewable sources of energy, or at least reduce our need for it. It may be able to cut down on our impact on the world enough to save it from being irreversibly damaged.

Solutions for Space and Rural Area Housing

So a little more on these underground homes. Gideon Golany has researched different types of homes using earth-sheltered technology around the world. Many of his study areas have been focused in rural regions with little to no advanced technology available for constructing energy efficient homes. Some of these regions are also greatly lacking in construction materials, such as some arid regions in Tunisia, and some are just generally lacking in space due to over crowding, such as China. A list and preview of some of his books and papers can be found here.

Golany traveled to many of these areas to study the efficiency of maintaining temperatures for comfort and how they can save space in overcrowded regions. Many of these building techniques have been taken from ancient housing designs from each region. These can teach us a lot about how to use passive practices to maintain a comfortable environment inside our homes. This could reduce our impact on the environment.

Golany's studies in China tested the efficiency of two typed of homes. In the rural regions he tested, he found that completely underground dwellings radiating from a central courtyard were less efficient than dwellings located in the cliff face. This is because the air in the courtyard dwellings becomes stagnant. It heats up to uncomfortable temperatures in the summer and becomes cold because of a lack of sun penetrating the courtyard in the winter. This problem with stagnant air does not exist in the cliff side dwellings because air circulates much more readily past the front face of a dwelling.

This is important for more technologically advanced earth-sheltered homes as well. Ventilation is very important for these houses, because they are only exposed on one side. For the more natural houses it is an important factor in maintaining a comfortable temperature and preventing a stagnant feel inside the home. Various ventilation systems can maintain a comfortable atmosphere within advanced earth-sheltered dwellings and normal air conditioning systems may also be used to maintain the small comfort window down to an exact cue. These systems, as discussed earlier, may be much smaller, and therefore less expensive than those meant for conventional homes.

Mole Men in Our Future?

Have you ever considered living underground? Well, not completely underground necessarily, but in an earth-sheltered home? I've been dreaming about the day when I could live in one of these unique houses of my very own. But before that happens, is it really worth it?

There are a number of benefits to owning an earth-sheltered home, such as reduced heating bills, environmentally friendly living, and no great loss of yard space! One company, Earth Sheltered Technology, Inc., offers a list of benefits to owning an earth-sheltered home, as well as some designs and frequently asked questions.

The main selling point of the houses for me is their efficiency of heat use. The company claims that their houses are up to 80% more efficient than standard home. This of course means that many of their homes are less efficient than this, since that is the maximum efficiency. Because of this efficiency, however, you would need a system that was only about 1/4th the power of a normal heating system. You could also then combine this with newer, energy efficient technology, such as geothermal, passive solar, and efficient light bulbs such as LED (expensive but the most efficient for now).

If you were to build the house with the windows facing south and with an over hanging roof, it will be warmed in the winter when the sun is lower in the sky and be more shaded in the summer when the sun is higher. All these little things have the potential to greatly reduce energy bills and make an earth-sheltered home even more sustainable.

Follow up

Here is Speaker Pelosi thanking Power Shifters for their lobbying efforts and accomplishments.

Power Shift

Over the past weekend I attended a conference, along with 10,000 other young people, called Power Shift. This was a great experience for me and I would like to encourage anyone interested in environmental and sustainability issues to go next year. There were a number of panels and workshops presented by leading researchers, entrepreneurs, and leaders in many fields concerning sustainable power and how to achieve it.

This was a great experience that allowed me to learn a little bit more about different methods of combating the energy crisis. Many of the forums focused on our dependence on oil or on new energy sources, such as wind, geothermal, and solar. One of the forums I attended looked at making buildings more energy efficient. This one was especially informative and covered everything from what types of insulation work best in new buildings to how to go through old buildings and find ways to improve their energy efficiency with minor upgrades.

One work in progress that one of the panelists mentioned was a water heater, for any sort of building, that would use the heat normally lost from the hot water holding tank to reheat the water in loop. This would greatly reduce loss of energy from the hot water and recycle it for more efficient water heating. The panelist mentioned that it has the potential to take the water heating bill for a normal family home from about $75 down to about $16 a month.

Other more simple updates can be made to your home or the places you work, such as using more energy efficient light bulbs and eliminating "decorative" lighting fixture. Replacing old windows with new, more insulating ones is also becoming a popular investment. These methods are especially important for old buildings that cannot handle major renovations, but that have e tendency to drain power and have high energy bills.

Consider going though your home or office and looking for minor upgrades that will help us all in the long run.