Optimal Control Strategies for Passive Heating and Cooling Elements Reduce Loads by Two-Thirds in the Adaptive Reuse of a San Francisco Bay Area Office

Syracuse, NY

Housing crises in urban centers and growing climate concerns are encouraging city planners and building owners to explore the conversion of commercial buildings into energy-efcient dwellings. Passive solar heating, shading, and natural ventilation are attractive in such adaptive reuse projects since they minimize operational energy, but they sufer from the perception of limited efectiveness, and passive heating is ofen disregarded entirely in cloudy climates. At the same time, passive heating has recently shown promise in the cloudy winters of western Oregon and upstate New York, allowing the San Francisco Bay area to provide an excellent opportunity for further exploration. Passive cooling measures, in turn, are essential to prevent overheating. Tis work investigates the conversion of a brick ofce space in Berkeley, CA into a residential lof, using movable insulation, operable windows, thermal mass, and shading to diminish the need for mechanical conditioning to the extent possible. To determine this extent, preliminary explorations in EnergyPlus were followed by Hooke-Jeeves and particle-swarm optimizations of control thresholds, following feld-validated techniques for passive heating and cooling simulation. Optimized parameters included skylight tilt; schedules for movable insulation, shading, and natural ventilation; and thermal mass quantity, each required to minimize annual sensible heating and cooling energy while maintaining adaptive thermal comfort. With optimal control, over half of the heating need could be met by passive solar collection and storage; likewise, most cooling (~80%) could be accomplished passively if shading and natural ventilation were well-controlled. Without these controls, most of the beneft was lost. We therefore propose replacing the term “passive” with “well-controlled passive” to refect the importance of controls in sensing conditions and adjusting movable elements to maximize the performance of these systems.

https://surface.syr.edu/ibpc/2018/GB1/4