Exploiting a hybrid environmental design strategy in a US continental climate

Resistance to the widespread adoption of naturally ventilated buildings in North America derives from the exigencies of the ‘continental climate’ type: humid hot summers and cold, desiccating winters. The paper describes a proposed new hybrid strategy for conditioning the environment in the new library and faculty building for Judson College, Elgin, Illinois, US. The strategy exploits the significant mid-season opportunities for implementing natural buoyancy-driven displacement ventilation and passive cooling in the continental climate of the Chicago hinterland. Both the natural and mechanical modes of operation are described and put in the context of current thermal comfort criteria for wholly mechanical and wholly natural ventilation. Predictions are given of the annual duration of the various operating modes and the building’s likely overall energy performance using a standard reference year. Construction and energy costs are compared with those for a US Standard Building. An account is given of the various barriers encountered in introducing the innovations.