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
| Mar 8, 2012
Green buildings more resilient than conventionally built structures
A new study by the U.S. Green Building Council (USGBC) and the University of Michigan’s Taubman College of Architecture and Urban Planning suggests that structures built to green standards can advance building resiliency.
| Mar 1, 2012
LEED Platinum standard likely to mean net-zero energy by 2018
As LEED standards continue to rise, the top level, LEED Platinum, will likely mean net-zero energy construction by 2018.
| Mar 1, 2012
EPA beefs up stormwater discharge rule from construction projects
The U.S. Environmental Protection Agency (EPA) has now finalized its 2012 construction general permit (CGP) that authorizes stormwater discharges from construction projects that disturb one or more acres of land in the areas where EPA is the permitting authority.
| Mar 1, 2012
Regulators investigate structural failures during construction of two Ohio casinos
Regulators with the Occupational Safety & Health Administration and the city of Cincinnati are investigatingthe collapse of the second floor of Cincinnati's Horseshoe Casino as workers were pouring concrete.
| Mar 1, 2012
Is your project too small for LEED? Consider other green standards
There are many other recognized national, state and local programs that offer a variety of best management practices and sustainable design, construction and operating strategies.
| Mar 1, 2012
California bill aims to cut costs for commercial building energy retrofits
A bill in the California Assembly would allow the state to pool together property owners’ energy-retrofit loans.
| Feb 29, 2012
Carvalho appointed Shawmut Safety Director
He has been a driving force behind multiple safety-orientated initiatives at Shawmut, including Safety Week, the creation of an online safety manual, and the implementation of a new safety reporting and tracking system.Â
| Feb 23, 2012
Federal budget cuts put major building projects on hold
A plan to build the National Bio and Agro-Defense Facility in Kansas is among several major building projects in jeopardy after the Obama administration’s 2013 budget was unveiled. The budget would cut all construction spending for the facility.
