The ultimate improvement in energy efficient building design is Passive Annual underground Heat Storage. How much more of an improvement can be made?
This ultimate energy conservation process is surprisingly simple: The sun heats the house and the house heats the earth. When the sun isn't out, the earth heats the house. Although the physics of underground heat flow is complex, Passive Annual underground Heat Storage can be easily applied by knowing a few easy to understand principles.
How well we understand the way things work determines how well the houses we design will work. We must also know how things donot work. Since a design based on erroneous assumptions willnot work or, at best, will not work well.
Still, the most advanced book available on the subject is Passive Annual Heat Storage - Improving the Design of Earth Shelters. This 1983 text is still quite up to date as it teaches the basic methods of understanding natural heat flow methods that never change. Other supplementary materials, home plans and instruction videos are available.
You can order books, videos, and papers on a large variety of topics which are available from the Rocky Mountain Research Center.
Baked dry in August, frozen stiff all winter, a Montana sod buster and his neighbors battled the elements. They shivered through the frigid northern winters, gathering buffalo chips for fuel to ward off the frostbite.
Our field farming friend noticed that the vegetables in his root cellar never got hot and never got cold. They were always comfortable. He wasn't! So he installed a window in his root cellar and moved in.
Within the first year, the unheated indoor temperature rose from its natural 45 degrees (7 C) to 55 degrees (13 C), all by itself. This drastically reduced the amount of fuel he needed, but his neighbors just laughed at him and continued gathering buffalo chips.
This rise in temperature was a surprise improvement, since everyone had told him that it would always be 45 degrees (7 C) no matter what. Mulling this over in his mind he thought: "If I could only raise the temperature another 10 or 15 degrees (6-8 C), I wouldn't need buffalo chips at all."
But how can you intentionally raise the temperature that occurs naturally in the earth? Well, he had already raised that average temperature about 10 degrees by installing the window. He reasoned, "It must be like raising the natural level of a lake. You let more water in and less water out. That's it!"
He grabbed his hat and dashed into town. Soon he returned with a pickup load of hard foam insulation and several rolls of plastic sheeting. He put the insulation and plastic over the top of his home, dirt and all, and covered the whole thing with another layer of earth.
All summer long, the heat which collected inside soaked into the ground to keep his home cool and comfortable. Just as he had suspected, the newly insulated earth began warming up from 55 to 65 (13 - 18 C) and by fall, all the way up to 71 degrees (22 C). When cold weather arrived, the earth remained warm and kept his new earth sheltered abode cozy all winter. Our subterranean sod buster was at last continuously comfortable. He had invented Passive Annual underground Heat Storage!
And his neighbors? Well, times have changed. Now a big monopoly collects and distributes all the buffalo chips and goes to the Public Service Commission each month to ask for another rate hike.
Passive Annual Underground Heat Storage - The Ultimate Improvement
An ultimate energy conservation system should:
Be simple and straightforward.
Work on the natural annual heat cycle.
Collect and store free heat whenever it is available.
Automatically bring the heat out of underground heat storage when needed.
Provide ALL of a home's heating and cooling needs.
Provide a continuous supply of fresh air.
Provide a surplus of energy for other needs.
Not use mechanical equipment.
Never break down or wear out.
Work in climates all over the world.
Be inexpensive and easy to build.
Developing Passive Annual Underground Heat Storage - An Illustration
Underground Heat Storage
Even the conventional earth shelter climatizes the earth around it to some extent. Passive Annual underground Heat Storage allows the newly climatized floating temperature to be adjusted up to a comfortable year round level!
Since the heat that comes through the windows of a subterranean home may now be contained, it will be stored in and released from the earth for at least 20 feet (6 m) by means of conduction. It is, therefore, conduction accessed underground heat storage. The working temperature of this conduction accessed underground heat storage is controlled by adjusting the indoor average annual air temperature.
The Underground Heat Storage Configuration
Earth's well balanced traits such as: heat storage, temperature moderation, thermal resistance, structural uses and low cost, make earth the most practical building material of all. Understanding how it really functions will allow us to define the several thermal jobs that the earth will accomplish, when we use it right. This will provide the pioneer with a suitable set of guidelines, starting points, basic sizes and configurations. These lay a foundation for the pioneering work in Passive Annual underground Heat Storage.
The different jobs that earth will perform for us depend on: where it is in relation to the house, how it is insulated, the length of the conductive paths to the nearest surfaces, and the average temperature it functions at. Three zones of heat conducting earth can then be identified by their thermal functions. They are:
