<p> Life cycle assessment (LCA) can aid in quantifying the environmental impacts of whole buildings by evaluating materials, construction, operation and end of life phases with the goal of identifying areas of potential improvement. Since buildings have long useful lifetimes, and the use phase can have large environmental impacts, variations within the use phase can sometimes be greater than the total impacts of other phases. Additionally, buildings are operated within changing industrial and environmental systems; the simultaneous evaluation of these dynamic systems is recognized as a need in LCA. At the whole building level, LCA of buildings has also failed to account for internal impacts due to indoor environmental quality (IEQ). The two key contributions of this work are 1) the development of an explicit framework for DLCA and 2) the inclusion of IEQ impacts related to both occupant health and productivity. DLCA was defined as “an approach to LCA which explicitly incorporates dynamic process modeling in the context of temporal and spatial variations in the surrounding industrial and environmental systems.” IEQ impacts were separated into three types: 1) chemical impacts, 2) nonchemical health impacts, and 3) productivity impacts. Dynamic feedback loops were incorporated in a combined energy/IEQ model, which was applied to an illustrative case study of the Mascaro Center for Sustainable Innovation (MCSI) building at the University of Pittsburgh. Data were collected by a system of energy, temperature, airflow and air quality sensors, and supplemented with a postoccupancy building survey to elicit occupants’ qualitative evaluation of IEQ and its impact on productivity. The IEQ+DLCA model was used to evaluate the tradeoffs or co-benefits of energy-savings scenarios. Accounting for dynamic variation changed the overall results in several LCIA categories—increasing nonrenewable energy use by 15% but reducing impacts due to criteria air pollutants by over 50%. Internal respiratory effects due to particulate matter were up to 10% of external impacts, and internal cancer impacts from VOC inhalation were several times to almost an order of magnitude greater than external cancer impacts. An analysis of potential energy saving scenarios highlighted tradeoffs between internal and external impacts, with some energy savings coming at a cost of negative impacts on either internal health, productivity or both. Findings support including both internal and external impacts in green building standards, and demonstrate an improved quantitative LCA method for the comparative evaluation of building designs.</p>
| Identifer | oai:union.ndltd.org:PROQUEST/oai:pqdtoai.proquest.com:3573266 |
| Date | 24 September 2013 |
| Creators | Collinge, William O. |
| Publisher | University of Pittsburgh |
| Source Sets | ProQuest.com |
| Language | English |
| Detected Language | English |
| Type | thesis |
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