opinion regarding maximum fresh air in ventilation. The understanding should be conveyed that the supply air to the rooms would be virus-free before or after the original guidelines and the GHG emissions addition can be avoided if the systems are allowed to control under energy conservation logic that existed prior to the COVID-19 issue. Facility staff will not likely alter the public and teacher unions’ opinion for maximum fresh air without very clear and public support of ASHRAE indicating the new position will not negatively impact the effort to correct the COVID-19 fight, but will prevent further damage to the planet via unnecessary GHG emissions. The comparisons of earlier ASHRAE guidance to the October 5, 2020 ASHRAE guidance are: 1) August 20, 2020 “Ventilation: A good supply of outside air, in accordance with ASHRAE Standard 62.1-2019, to dilute indoor contaminants is a first line of defense against aerosol transmission of SARS-CoV-2. Pre- and post-occupancy purge cycles are recommended to flush the building with clean air.” October 5, 2020: “Pre- or Post-Occupancy Flush with Outdoor Air: Focus on removing bio-burden pre-or post-occupancy of the building. Flush building for a time required to achieve three air changes of outdoor air (or equivalent, including effect of outdoor air, particulate filtration, and air cleaners).” Red highlighting added. 2) July 22, 2020: “During the Pandemic, disable any Demand Control Ventilation (DCV) and introduce the maximum possible OA flow 24/7 until further notice (including DOAS).” October 5, 2020” “Energy Savings: During Evaluation and Inspection, determine optimized control strategies that can be implemented per ASHRAE Guideline 36-2018, High-Performance Sequences of Operation for HVAC Systems.” October 5, 2020: “Modes of Operation for the Building: Operate in Occupied Mode when people are present in the building, including times when the building is occupied by a small fraction of its allowable capacity.” 3) October 5, 2020: “Ventilation and Filtration: Confirm systems provide required minimum amounts of outdoor air for ventilation and that the filters are MERV 13 or better filters for recirculated air. Combine the effects of outdoor air, filtration, and air cleaners to exceed combined requirements of minimum ventilation and MERV-13 filters. The environmental benefits in the apparent shift are: 1) From two purge cycles a day to one is a 50% reduction in additional pollution generated. 2) The shift from disabling the Demand Control Ventilation to maintaining energy conservation logic is a potential 700% improvement in pollution reduction on some fan systems. 3) The shift from running fans 24/7 on maximum fresh air to operate in Occupied Mode when people are present in the building is the greatest reduction in additional pollution generation. 11.198
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