Numerical optimization of integrated passive heating and cooling systems yields simple protocols for building energy decarbonization

Passive heating and cooling systems have the potential to reduce space-heating and space-cooling loads in buildings significantly, with minimal embodied energy investment and extremely low operational energy demand. Excellent performance requires movable insulation, operable shading, operable vents, and other adjustable elements, but effective methods for controlling their operation have not yet been established. In particular, the numerical optimization of interdependent passive heating and cooling parameters to maintain thermal comfort has not yet been demonstrated; development of simplified control strategies has not been explored; and resulting load reductions have not been estimated. Here, we investigate these problems in planning for the adaptive reuse of an historic brick office building in the Mediterranean climate of Berkeley, California. Using Hooke-Jeeves and particle-swarm optimizations of passive system parameters in a field-validated EnergyPlus model, constrained to develop monthly schedules responding only to time or temperature, we find that near-optimal configuration and control of passive solar collection eliminate over half of the baseline heating load; likewise, well-controlled shading and natural ventilation eliminate ?80% of the cooling load. Together, these results reveal the magnitude of the passive space-conditioning resource in this energy-intensive region and demonstrate the power of simple, effective operational strategies to realize substantial energy savings.