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ABSTRACT

During the COVID-19 pandemic, building owners and operators sought to protect their occupants by following ASHRAE and CDC guidance for HVAC and water system risk mitigation. This paper presents the results of building readiness assessments conducted for 95 commercial office buildings across the United States. In these assessments, the authors evaluated buildings for initial alignment with ASHRAE Epidemic Task Force (ETF) guidance and recommended action where additional risk mitigation measures were warranted. The engineering assessments focused on outdoor air ventilation rates, filtration efficiency levels, flushing spaces during unoccupied periods, and Legionella water management practices. Primary challenges to implementing ETF guidance included resistance to operational changes with potential adverse energy impacts, concerns regarding existing system limitations, and in a limited number of cases, ventilation system design constraints. The assessments showed that most of the office buildings could modify their HVAC and water system operating practices to minimize the spread of harmful pathogens without major upgrades to equipment or significant increases in energy use. Almost all subject buildings had the capacity to meet or exceed minimum ventilation rates, upgrade to at least MERV-13 filters, implement appropriate flushing periods to achieve target clean air changes, and manage their water systems to minimize Legionella risk.