Degree Type


Date of Award


Degree Name

Doctor of Philosophy


Mechanical Engineering


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,

Copyright Owner

Roy R. Crawford



Proquest ID


File Format


File Size

219 pages