Preliminary Study on Energy Efficiency Associated with Earth Buildings

Earth buildings are the buildings made of earth, at least for its main load bearing structure. In wider view, earth buildings are part of thermal mass building family including earth sheltered buildings, rammed earth buildings, etc. “Preliminary Study on Energy Efficiency Associated with Earth Buildings” is the research on the method to calculate the energy efficiency of earth buildings. There are also suggestions on the design for large scale (multi-story) earth buildings. An earth building is not only a type of green building but also a very old type of building. Today, there is a revival of earth buildings across the world owing to their friendliness to the environment. Unfortunately, the calculation of energy efficiency of earth buildings is entirely based on experience without any standard calculation method or standard experiment method. In term of scale, most earth building designs to date are small and thus low efficiency in land use. Designs of large scale earth buildings are almost absent from all sources of documents. This research will undertake two tasks: (1) to suggest the method for the calculation of energy efficiency of several earth building models. (2) to propose several large scale earth building designs to demonstrate potentials of large scale earth buildings. Thermal mass of an earth building is a complicated system, and its design and calculation are a huge task. Unfortunately, there is no whole-building energy simulation program for earth buildings which have earth cover thicker than 1m. Therefore, it is proposed that an earth building be converted to a conventional building to enable the use of the energy simulation program. However, this requires an experiment to provide inputs to run the whole building simulation. The experiment would include a test pipe, which is smaller than the tube but all the key thermal parameters are the same. The proposed designs for large scale earth buildings include several models that are the high-rise buildings of different sizes and shapes with two common points: the load-bearing structure is made entirely of earth that meets certain criteria and the useful spaces are located in the reinforced concrete tubes or square compartments embedded in the earth body. It is ideal that an earth building requires no air heating and cooling at all, which can be obtained by good combination of location and design. In an extreme climate where the average annual mean temperature is either too low or too high, air heating or cooling energy may be required. In short, earth buildings advantages include energy saving, greener outdoor environment, reduction in urban heat island phenomenon. Earth buildings also have some disadvantages such as high land use per occupant. This study helps enhance the advantages and minimize the disadvantages of earth buildings