Impact of design conditions on energy use: the case study of a health care facility

Heating, ventilation and air conditioning (HVAC) systems in healthcare facilities provide a broad range of services; in particular, ventilation is used extensively to provide safe and comfortable environments for patients and medical staff, affecting the distribution pattern of airborne particles. Primary patient treatment areas such as surgical departments are supplied by specific emitters that undergo continuous maintenance and inspection. Improperly operating and maintained HVAC systems can even become a source of microorganisms. Due to 24 hours/day, 7 days/week operation, healthcare facilities are responsible of large quantities of energy consumption. This works aims to assess the energy consumption of a surgical unit designed in compliance with ASHRAE 170, UNI 11425 and HTM 03-01, which led to different design approaches for the definition of ventilation rates, showing the impact of heterogeneous guidelines on the energy use; the standards defined design criteria implemented in an energy model carried out with the dynamic tool TRNSYS, performing in three different climatic conditions. Results show that energy demand varies significantly depending on the standard used, highlighting the importance of a unique reference standard describing technical recommendations for HVAC systems design in operating/surgical rooms to obtain safe and clean environments while avoiding energy waste.