Dynamic earth-contact building: A sustainable low-energy technology

Sustainable development includes low-energy buildings, which reduce energy consumption, green house gases emission, water usage, etc. The choice of subsurface wall at varying depths for construction of buildings has a direct impact on energy consumption and the environment. This paper includes in its scope all building structures in which a significant area is in direct contact with the earth, and excludes indirect earth contact. A two-dimensional simplified analytical Fourier boundary series was developed to study dynamic earth-contact heat transfer and humidity variation in building. It was used in conjunction with the whole-building energy simulation program developed in the TRNSYS environment. The predictions were compared with extensive experimental data measured from typical existing earth-contact buildings situated in the Indian Institute of Technology Delhi campus. Heat transfer through earth-contact building structures was predicted to decrease with increasing soil contact. The results obtained from the detailed model showed that earth-contact structures form excellent passive technology that can be exploited for energy conservation. This work is part of an effort to develop zero energy building models in India. The presented model can be easily incorporated into indirect earth-contact structures in order to describe the impact of cooling tubes, earth-air tunnels or heat pumps in indoor environment.