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 20, 2013
ANSI/CRRC Cool Roof Standard has been approved
The Cool Roof Rating Council says the American National Standards Institute has given final approval of its ANSI/CRRC-1-2012 Standard after a two-year public review process.
| Feb 20, 2013
Group of West Coast civil engineers developing building standards for tsunamis
A group of civil engineers from around the western U.S. is developing additions to the building code to address the threat of a tsunami.
| Feb 20, 2013
Higher standards, efficiency programs keys to 40% energy usage reduction in commercial buildings since 1980
Commercial buildings have seen a drop in their energy intensity of more than 40% since 1980, according to a recent report from Bloomberg New Energy Finance and the Business Council for Sustainable Energy.
| Feb 12, 2013
Higher education institutions providing leadership on sustainability
More than 665 U.S. colleges and universities have publicly committed to pursue net-zero carbon emissions.
| Feb 12, 2013
ASHRAE publishes protocols for performance measurement
ASHRAE has published “Performance Measurement Procedures for Commercial Buildings: Best Practices Guide,” a how-to guide for continuously evaluating and improving the performance of commercial buildings throughout their service life.
| Feb 12, 2013
California resolves ADA inconsistencies with 2013 building code
The recently adopted 2013 California Building Code (CBC) revisions bring the state code in line with the federal Americans With Disabilities Act 2010.
| Feb 12, 2013
Bullitt Foundation says Living Building Challenge can only be met after code change
The 50,000 sf Bullitt Center in Seattle is being constructed to be the greenest, most energy-efficient commercial building in the world, and meet the ambitious goals of the Living Building Challenge.
| Feb 12, 2013
Tilt-Up Concrete Assn. offers technical advice on 2012 International Energy Code
The Tilt-Up Concrete Association (TCA) says it can be a major industry resource in helping designers adhere to the International Energy Conservation Code (IECC).
| Feb 8, 2013
WDMA releases national policy agenda for windows, doors, skylights
Document urges a regulatory stance that will support manufacturing, including favorable building codes and tax policy.
| Feb 6, 2013
Green-roofing bills approved by New Jersey's state Assembly
Two bills that would require installation of green and blue roofs on new government buildings received overwhelming approval from the state Assembly in New Jersey.
