Ventilation Against Disease Transmission in Hospitals: Evaluation of risk levels and energy consequences

Abstract

ABSTRACT Ventilation plays a critical role in controlling indoor air quality and reducing infection risks, particularly in healthcare settings where vulnerable populations are present. This study examines the effect of different airflow rates on infection control and highlights the differences between guidelines as well as specific national and international guidelines. Using field data from Kungälv Hospital in Sweden, along with simulations from the REHVA COVID-19 Ventilation Calculator and IDA ICE software, the study compares the impact of ventilation on high-risk diseases like measles and moderate-risk illnesses such as seasonal influenza. There are notable differences between the strictest and least stringent guidelines, with some recommending as low as 2 air changes per hour (ACH), while others suggest up to 12 ACH for isolation rooms. Results reveal that as the airflow rate increases, the infection risk decreases, but energy consumption also increases, raising concerns about sustainable building practices. Doubling the ventilation rate from 25 l/s to 50 l/s led to a substantial reduction in infection risk (37% relative reduction), but it also increased energy consumption, highlighting a critical trade-off. Furthermore, the findings show the impact of air cleaners on reducing airborne particles and the potential of integrating them into ventilation systems to enhance infection control. Alongside adequate ventilation, other measures such as utilizing UV lighting, promoting face masks, and reducing occupancy time are essential strategies to improve air quality in healthcare environments. These measures are particularly crucial post-COVID-19 pandemic, where preventing airborne transmission has become a major concern.