December 8th 2020

CFD Simulation for Hospital Operating Rooms (ORs)

CFD Simulation for Hospital Operating Rooms (ORs)

CFD Simulation is an important tool for designing ventilation systems in critical healthcare facilities. Given a typical Operating Room (OR), ‘ASHRAE Standard 170 - Ventilation of Health Care Facilities’ has useful guidance: 

  • Downward Laminar Flow Supply Diffusers: 25-35 cfm/ft2 (127-178 L/s/m2).
  • Two (minimum) low-level side-wall return or exhaust grilles:  ~8 inches above the floor (200 mm) and spaced at opposite corners, or as far apart as possible. 
  • Positive Pressure to all adjoining spaces.

The CFD Simulation graphics shown below uses the MicroFlo Application within IESVE Software. In this example, we are tracking particulates within the room and showing air velocity gradients. 

One common metric used for evaluating contaminant control is the Local Mean Age of Air (LMA), or ‘Age of Air’ for short.  The mean age of air is the average time the air has spent in a space accumulating unwanted contaminants. In the example below, the Operating Room (OR) has a requirement for 20 Air Changes per Hour (ACH); i.e. the room air is to be changed every 3 minutes. 

The area surrounding the patient and surgical team shows the Age of Air to be below 2 minutes. The laminar flow supply diffusers overhead prove to provide an effective ventilation strategy for this critical area in the surgical space. 

To learn how to setup a CFD Simulation, please review this FREE training webinar: