Hotels as quarantine facilities with airborne virus controls

Area of Science:

• Environmental Health Engineering
• Infectious Disease Control
• Building Science

Background:

• Hotels repurposed as quarantine facilities during COVID-19 often lacked effective air-cleaning systems.
• Viral aerosol transmission, particularly between zones, posed a significant risk to quarantine effectiveness.
• Controlling inter-zonal transmission is critical for isolating infected individuals in shared facilities.

Purpose of the Study:

• To design and evaluate effective air-cleaning strategies for quarantine hotels.
• To assess strategies for minimizing viral aerosol transmission, especially between different zones.
• To develop an index for evaluating the performance of air-cleaning infrastructure.

Main Methods:

• Development of a validated multi-zone model of an actual quarantine hotel.
• Introduction and application of the inter-zonal air exchange rate (zACH) index.
• Evaluation of various air-cleaning strategies, including UVGI, HEPA filters, air curtains, and combined approaches.

Main Results:

• The inter-zonal air exchange rate (zACH) significantly improved with air-cleaning strategies.
• Individual air-cleaning devices (UVGI, HEPA, air curtains) yielded zACH values of 3.5, 2.8, and 1.7 1/h, respectively.
• The optimal combined strategy achieved a zACH of 8.5 1/h, reducing maximum infectious exposure risk to below 0.4% in rooms and 1.6% in corridors.

Conclusions:

• A comprehensive air-cleaning strategy can effectively mitigate viral aerosol transmission in quarantine hotels.
• Optimizing air-cleaning requires balancing effectiveness with cost and energy considerations, as performance is not linear with device count.
• The findings provide a framework for improving infection control in quarantine settings and inform future pandemic mitigation efforts.