Benefits of Outside Air (12-05-19)

McArthur simulated the experience of being in “large offices in all climate zones . . . with various outdoor air rates,” and documented the significant performance/economic benefits that result from relatively high outdoor air ventilation rates.  The researcher shares that “A benefit-cost analysis considered energy costs and carbon emission offsets to achieve net-zero carbon operation for large office buildings across international climate zones with ventilation rates ranging from 125% to 1000% ASHRAE 62.1 minimums. Key findings: (1) the productivity benefit was substantially larger than the incremental energy costs; (2) carbon offset costs were relatively low compared with energy costs and had a negligible effect on results; (3) increasing outdoor air resulted in consistently increasing net benefits on an area basis; and (4) the benefit-cost ratio was inversely proportional to the severity of the climate, with the most moderate climates actually showing a net energy decrease with elevated outdoor air.” A definition: “ANSI/ASHRAE 62.1 defines the minimum allowable outdoor air for all building types excluding low-rise residential buildings.”

J. McArthur.  2020.  “Rethinking Ventilation:  A Benefit-Cost Analysis of Carbon-Offset Increased Outdoor Air Provision.”  Building and Environment, vol. 169, no. 106551,