As scientists learn more about the COVID-19 virus, opinions are changing on how it is spread from person to person, and that has implications for how to reopen buildings safely.
Emphasis to date on protocols for reopening buildings has focused on surface cleaning and occupant density. But, if as some scientists suspect, the virus can live for at least three hours in aerosols—tiny particles that can be carried through the air for long distances—HVAC systems could play a key role in spreading the virus. There are opposing views on whether aerosols actually can transmit the virus, but if they do, then ventilation systems could spread the virus through unfiltered re-circulation of indoor air.
In April, ASHRAE addressed the issue of possible aerosol transmission with recommendations that include:
· Maintain a relative humidity of 40% to 60% inside buildings instead of the usual 20% to 40%.
· Install air filters rated at least at MERV-13.
· Minimize re-circulation of indoor air, and bring in outside air either by mechanical means or by opening windows.
The humidity recommendation was made because higher humidity makes aerosols heavier, causing them to drop to the floor faster. ASHRAE has also recommended that the intake of outside air be set to the highest level permitted by the mechanical equipment. Some specialists recommend a full re-commissioning process for reopening buildings.
Related Stories
| Jul 31, 2014
Cambridge, Mass., is latest locale to require energy usage disclosure
The City Council of Cambridge, Mass., approved the Building Energy Usage and Disclosure Ordinance (BEUDO) that requires benchmarking and disclosure of building energy performance for large commercial, institutional, and multifamily buildings.
| Jul 31, 2014
Stalled $1.5 billion Miami mixed-use redevelopment project advances
A long-delayed $1.5 billion mixed-use development in Miami moved ahead after city planners approved the project’s first phase.
| Jul 30, 2014
USGS updates National Seismic Hazard Maps
The U.S. Geological Service recently released an update of U.S. National Seismic Hazard Maps that reflect the latest analysis of where future earthquakes will occur, how frequently they may occur, and their strength.
| Jul 23, 2014
Fairfax County, Virginia toughens green standards
The Fairfax County Board of Supervisors recently strengthened its green building policy, requiring higher standards for residential, retail, office and other construction projects seeking approval for rezoning.
| Jul 23, 2014
Berkeley National Lab’s FLEXLAB is a test bed for energy efficient office design
FLEXLAB, short for the Facility for Low Energy Experiments, opened this summer at the Lawrence Berkeley National Laboratory.
| Jul 23, 2014
House passes 2015 GSA budget with 17% cut for new construction projects
The General Services Administration’s construction budget for fiscal year 2015 passed by the House this month includes cuts in both new construction and renovation/repairs compared to 2014.
| Jul 16, 2014
Coastal flooding increasing along East Coast, says report
An analysis of tidal levels and flood data by the news organization Reuters concludes that flooding has increased along the Eastern Seaboard over the past four decades.
| Jul 16, 2014
Local hiring requirement a tough challenge for new Detroit arena project
An agreement for a land transfer from the City of Detroit to Ilitch Holdings Inc., that enabled construction of a new arena for the Detroit Red Wings requires that 51% of the project’s construction workers must come from the city.
| Jul 16, 2014
Local hiring requirement a tough challenge for new Detroit arena project
An agreement for a land transfer from the City of Detroit to Ilitch Holdings Inc., that enabled construction of a new arena for the Detroit Red Wings requires that 51% of the project’s construction workers must come from the city.
| Jul 16, 2014
Massive $6.5 billion Silicon Valley development gets key city approval
The Santa Clara (Calif.) City Council approved the next steps for a massive development project next to Levi’s Stadium, the new home of the San Francisco 49ers.
