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
| 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.
| Feb 23, 2012
Federal agencies fixed on leasing LEED-certified space
The federal government is especially focused on renting LEED-certified spaces.
| Feb 23, 2012
Regulators investigating construction accident at World Trade Center
The New York Port Authority and the city’s fire and building departments are investigating an accident at the World Trade Center construction site in lower Manhattan after a crane dropped steel beams that fell about 40 stories onto the truck that delivered them.
| Feb 23, 2012
New Virginia statewide building code goes into effect March 1
After March 1, all building plans in Virginia must adhere to the 2009 code that was adopted a year ago.
| Feb 23, 2012
Privatizing flood insurance could lead to new code requirements
One thing that could pave the way toward private flood insurance would be NFIP reforms, like requiring new construction in flood-prone areas to be elevated.
| Feb 22, 2012
ACI BIM manual for cast-in-place concrete in development
The improved communication, coordination, and collaboration afforded by BIM implementation have already been shown to save time and money in projects.
| Feb 20, 2012
Comment period for update to USGBC's LEED Green Building Program now open
This third draft of LEED has been refined to address technical stringency and rigor, measurement and performance tools, and an enhanced user experience.
| Feb 20, 2012
GAF introduces web portal for architects and specifiers
The new portal offers a clean look with minimal clutter to make it easier to find the technical information and product data that architects need.
