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
| Dec 1, 2011
Safety tracking tool helping prevent injuries at World Trade Center site
Since putting in place their Safety Management Systems Tracking Tool three years ago, risk managers for the World Trade Center project in New York say they've seen workplace injuries, reported hazards, and workers compensation claims decline.
| Dec 1, 2011
OSHA releases new construction safety videos
OSHA released new safety videos to offer both employers and workers brief, easy-to-understand education about construction safety.
| Dec 1, 2011
GSA Region 5 BIM standards could set national agenda in government contracting
Learning how the GSA wants to work with contractors using Building Information Models (BIM) will dramatically improve your odds of winning federal work.
| Nov 23, 2011
Fenestration council seeks committee members
The National Fenestration Rating Council (NFRC) is seeking members for a committee to pursue recognition of its ratings procedures from the American National Standard Institute (ANSI).
| Nov 23, 2011
Obama signs repeal of 3% withholding on government contracts
President Obama signed a bill that repeals a law requiring governments to withhold 3% of payments over $10,000 to contractors.
| Nov 23, 2011
USGBC launches app lab for LEED certification process
The U.S. Green Building Council has released the App Lab, a searchable catalog of third-party apps that are integrated with LEED data.
| Nov 23, 2011
Document gives advice on stormwater runoff management
The report, “Rooftops to Rivers II,” provides tips on how cities can use smart infrastructure and green building design to minimize pollution from stormwater runoff and other wastewaters.
| Nov 23, 2011
Zoning changes proposed to make New York City buildings greener
New York City will introduce new zoning proposals next month that would make it easier for building owners to add features that will make their properties more sustainable.
| Nov 18, 2011
AGC offers webinar on Davis-Bacon compliance
Webinar to be held in two sessions, Dec. 7 and 8 from 2:00-3:30 p.m. EST.
| Nov 18, 2011
New green construction code may help push LEED standards higher
The International Green Construction Code (IgCC) is expected to set a floor for building standards and may create the opportunity for LEED certifications to push toward higher ceilings.
