(Georgia Institute of Technology, 2018-07-30)
Chen, Jianli
As one of the largest energy consumers in our society, commercial buildings take up approximately 20% of total energy consumption based on the data from Department of Energy (DOE). Among this energy consumption, nearly half of it is consumed by air conditioning systems for maintaining a comfortable thermal environment for building occupants. Despite this high energy consumption, complains of thermal comfort and health problems still commonly exist in air-conditioned buildings. The mean building satisfaction rate was only reported as 59% based on a large survey of building occupants, which is far below the minimum thermal comfort requirement in ASHRAE standard 55. Meanwhile, there also exist health problems in air-conditioned buildings, which include both building related diseases (typically caused by specific exposure to infectious indoor source) and sick building syndrome, which describes a group of general symptoms including eye or throat irritation, shortness of breath, visual disturbance etc. Thus, in these years, coupling natural ventilation with mechanical ventilation, hybrid ventilated buildings have attracted more attention from both academia and industry with increasing awareness of building sustainability. Hybrid ventilated buildings have the potential to minimize the energy bills for owners without compromising the thermal comfort of building occupants. Compared to the mechanical ventilated building, the hybrid ventilation system allows opening the window when the outdoor environment is favorable, which provides occupants with amenity to nature and saves energy in the building operation. Compared to the natural ventilation building, the hybrid ventilation building could protect the building occupants from the unfavorable outdoor environment with air conditioners on. As the first step to further popularize the hybrid ventilation building, this dissertation will provide a thorough investigation of the hybrid ventilation potential across different US climates with accounting for comprehensive and influential aspects related to the usage of natural ventilation, including different levels of uncertainties a hybrid ventilation building could experience, the influence of building intelligence and the impact of outdoor air quality. How to better assess the thermal comfort risks and utilize simulation to design this type of building will also be presented.
(Georgia Institute of Technology, 2006-11-15)
Fernandez-Solis, Jose Luciano
The construction industry is a major emissions contributor and a main resource consumer. Because of this, the industry is formulating short and long-term 'sustainability targets'. The trend points towards an unsustainable future, within the next 75 years, due to actual and projected increases in resource consumption and emissions generation in response to global population growth, and improving living standards, affluence.
There are no reliable studies that predict whether the required reductions in ecological impacts can actually be realized, and if so, on what time scale. In fact, currently no available system representations of the industry can serve as the basis for studying long-term sustainability through the twenty-first Century. Hard dynamic systems, based on reductionism, are no longer adequate representations to study the dynamics of complex systems. A worldview that includes complexity requires foremost a philosophical induction (a theory) of the nature of all the forces that move the industry and a mechanism for understanding how complex forces aggregate and affect growth.
The dissertation examines the current understanding of the Theories of Complexity in general, and in building construction, as preparation for a deeper understanding on how sustainability and its opposite, exponential growth (or "exponentialoid") relate. Guaranteeing sustainability transcends the current arsenal of counter measures such as LEED, high-performance measures, waste containment, conservation, lessening demand, renewable resourcing, greening of the industry, creation of high-performance buildings, penalizing the polluter, carbon trading, and others… Sustainability is re-framed as the (artificial) force that tames an unsustainable exponentialoid.
Sustainable forces are represented by elements of influence acting like vectorials that appear to have identifiable origin, direction and magnitude. A hypothetical example of how the heuristic/theory works is presented, pending future studies (needed to supply the necessary data required for a working model). This is pre-paradigmatic work, using both a novel worldview and method of analysis that points to increasingly detailed research work to be performed in the future.