What matters in the environmental performance of campus buildings? Interactions of building envelope, energy systems and user behavior

Buildings and building management are integral to efforts to reduce energy consumption, improve energy efficiency and reduce environmental impacts worldwide. Although impacts associated with building materials are significant,... [ view full abstract ]

Buildings and building management are integral to efforts to reduce energy consumption, improve energy efficiency and reduce environmental impacts worldwide. Although impacts associated with building materials are significant, the majority of life cycle impacts occur during buildings use phase through consumption of energy for various purposes. In the US, between 60-75% of energy supply to buildings is for thermal comfort (heating and cooling) and hot water. Indoor environmental quality (IEQ) can have dramatic implications for productivity of occupants in office and educational buildings, and can be indicative of well-being in residential buildings. Efforts to improve environmental performance of buildings over their lifecycle can be combined with enhancing the IEQ. This research will examine the following hypothesis:

Current energy use for provision of thermal comfort and hot water in buildings involves a lot of waste due to lack of occupancy monitoring, poor thermal performance of building envelope and dated heating/cooling system design.

Heating and cooling system characteristics and fuels do not act alone in determining environmental impacts of energy use in buildings, but interact strongly with climate, building thermal envelope, and occupant behavior. An integrated hybrid LCA model developed to assess electricity system scenarios [1] is being extended to included detailed descriptions of heating and cooling technologies, thereby providing a more complete coverage of the energy sector. This iteration of the model is being designed to assess life cycle impacts of electrical and thermal energy provision in buildings in general. A first case study will examine a significant portion of the Yale University campus. Results will of the LCA model will determine the extent of the effects of heating/cooling technology and energy sources on life cycle environmental impacts.

Some particularly novel features are contained in the research design. First, areas where designs for ‘resilient’ buildings (in preparation for potential shocks to energy/electricity supply) overlap with improved energy and environmental performance will be screened and assessed from practical and environmental perspectives. Second, three separate energy supply systems to the camps will be analyzed by measuring the respective lifecycle GHG emissions and cumulative energy demands. The three supply systems are 1) the current system, a gas fired combined heat and power (CHP) plant together with a steam/electric powered chiller plant 2) separate heat and power (SHP) supplied by utility electricity and gas 3) simultaneous heat and cooling produced by an electric heat recovery chiller with thermal energy storage, residual gas boiler heating, and utility electricity. Further research will examine interaction of occupants with building energy performance and IEQ, in terms of thermal comfort and perceived productivity.

[1]       T. Gibon, R. Wood, A. Arvesen, J. D. Bergesen, S. Suh, and E. G. Hertwich, “A Methodology for Integrated, Multiregional Life Cycle Assessment Scenarios under Large-Scale Technological Change,” Environ. Sci. Technol., vol. 49, no. 18, pp. 11218–11226, 2015.