HVAC through a sufficiency Lens: Reframing comfort and energy demand in buildings

While building HVAC system research has long emphasized energy efficiency, efficiency alone cannot deliver the emission reductions required in the building sector. The sufficiency approach aims to reduce overall energy demand while maintaining thermal comfort, well-being, and equity. This article defines the concept of sufficient HVAC; explores existing and emerging strategies such as adaptive comfort, zoning, and occupancy-based operation, and proposes a set of metrics for evaluating HVAC perfo