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
| Apr 19, 2012
Michigan legislature tackling controversial rules on electricians
A fight is brewing in the Michigan legislature over how many fully qualified electricians must be present during electrical work when apprentices also are on hand.
| Apr 19, 2012
Washington city may base building code on rising sea level due to global warming
Aberdeen may become the first city in Washington to base a building code on rising oceans and global warming.
| Apr 19, 2012
CSI webinar on energy codes and building envelopes
This seminar will review recent changes in energy codes, examples of building enclosure wall assemblies for code compliance, potential moisture management and durability challenges, and design tools to assess and minimize potential problems.
| Apr 19, 2012
Innovative plan for storm water in Philadelphia gets EPA’s OK
Philadelphia's $2 billion plan to manage its storm water with green methods including porous pavement, green roofs, and more trees, was officially approved last week by the U.S. Environmental Protection Agency.
| Apr 19, 2012
LEED 2012 to include new credit category for transit-oriented development
The updated LEED 2012 system will introduce a new credit category, “Location and Transportation,” to encourage development oriented around public transit and more walkable communities.
| Apr 17, 2012
FMI report examines federal construction trends
Given the rapid transformations occurring in the federal construction sector, FMI examines the key forces accelerating these changes, as well as their effect on the industry.
| Apr 16, 2012
University of Michigan study seeks to create efficient building design
The result, the researchers say, could be technologies capable of cutting the carbon footprint created by the huge power demands buildings place on the nation’s electrical grid.
| Apr 13, 2012
Congress’s action doesn’t mean Pentagon can’t build LEED gold structures
Though Congress passed a defense budget preventing the Department of Defense from spending money to achieve LEED gold or platinum certification, the Pentagon may still end up constructing buildings to those standards.
| Apr 13, 2012
International Living Building Institute certifies first two Net Zero Energy buildings
A community building in Oregon and an office building in California are the first two projects to earn net-zero status under the International Living Building Institute’s Net Zero Energy Certification program.
