High-volume low-speed (HVLS) fan system is considered an effective means of reducing energy consumption and building operation cost. This study adopts a performance-based approach using a CFD tool, FDS to evaluate the impact of HVLS fans on fire detection and smoke spread in an atrium, with a focus on whether the intense airflow of HVLS fans would affect the activation of fire detection systems such as beam/smoke detectors, aggravate smoke/fire spread at early stage of a fire, and hence impose stress on smoke control system serving the large space. It demonstrates that energy-saving HVLS fans will bring adverse effects on fire life safety in large spaces and therefore recommends the implementation of such system draw attention from all building stakeholders (owner, designer, AHJ, etc.) about its fire safety risks. It is expected that amendments in future editions of building codes and standards address deficiencies caused by HVLS fan systems and provide corresponding design guidelines.