Date of Award
Doctor of Philosophy
Past research on the optimization of building performance has resulted in various control strategies which minimize building energy consumption while maintaining a specified level of indoor environmental quality (e.g., thermal comfort, mass air quality, lighting levels). The optimal control strategy proposed in this study uses a "performance index," which quantifies the "costs" of energy consumption and indoor environmental quality, to mathematically express the operating performance of a building;A procedure is developed for deriving a dynamic system model which relates the indoor environmental quality to the energy consumption of a building. A system model is derived, semi-empirically, from actual building performance data and is converted to a finite-difference, state-space form. A mathematical optimization procedure, based on "Pontryagin's Maximum Principle", the system model, and the performance index, is developed to determine the optimal control for a building which maximizes the indoor environmental quality while minimizing the energy consumption;The system modeling and optimization techniques are applied to a single-family residence with a forced-air, electric-resistance heating system. The resulting system model indicates good agreement between the actual and predicted indoor environmental quality (thermal conditions). The results of the optimization of a hypothetical intermittent occupancy scenario indicate that maximum energy savings with minimum comfort penalties are realizable at the beginning and end of occupied periods. The optimization of a time-of-day electric rate structure scenario indicates significant cost savings with only minor increases in discomfort as a result of systematically over-heating and over-cooling the structure to shift electrical loads from periods of high electric rates to periods of low electric rates;A procedure for incorporating the optimization techniques into an actual control strategy is proposed. The practical aspects of providing weather predictions, adaptive modeling, and occupant inputs are also discussed.
Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/
Roy R. Crawford
Crawford, Roy R., "Time-optimal control strategies for residential heating systems using state-space techniques " (1983). Retrospective Theses and Dissertations. 8465.