Evaluating airflow dynamics in operating rooms: A comparative study of low-cost and high-end air velocity sensors

¹ Department of Energy and Process Engineering, Norwegian University of Science and Technology - NTNU, Trondheim, Norway
² Department of Architecture & Technology, Norwegian University of Science and Technology - NTNU, Trondheim, Norway
³ Norconsult Norge AS, Sandvika, Norway
⁴ Norconsult Digital AS, Sandvika, Norway

Abstract

For indoor environmental control, especially in healthcare settings, precise understanding of airflow distribution is crucial due to its impact on energy efficiency, environmental comfort, and most critically, occupant health. Accurate airflow measurement is vital in operating rooms (ORs), where the quality of air directly influences surgical outcomes and patient safety. This study focuses on evaluating the performance of low-cost airflow monitoring systems in capturing the real pattern of laminar airflow in an OR lab, a key factor in maintaining a sterile surgical environment. To this end, the study employs an array of sensors, including low-cost Omron MEMS Flow sensors, intermediate AirDisSys 5000 anemometers, and the high-end Testo 400 air velocity probe, were placed at four levels from the operating table to the laminar airflow diffuser. Following calibration of low-cost sensors using Testo 400, those sensors conducted measurements at various levels in comparison to the data from Testo 400 and AirDisSys 5000. The advanced Particle Image Velocimetry (PIV) technique was employed for detailed analysis of the crucial area next to an imaginary patients wound, indicating strong turbulence there. Results reveals that the airflow turbulence intensity near the wound surface significantly increases, rising from below 5% to around 15%, meanwhile, the relative error of low-cost sensors also grows as the airflow nears the wound surface. The results of this comparative analysis provide a nuanced understanding of the performance of various air velocity measurement instruments, highlighting their respective strengths and limitations. This information is invaluable for both academic research and real-world applications, guiding healthcare facilities in enhancing their air monitoring systems.