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
| Aug 30, 2012
Public comment period is open for CRRC-1 standard
The CRRC-1 standard covers specimen preparation and test methods for measuring the initial and aged solar reflectance and thermal emittance of roofing products.
| Aug 30, 2012
LEED system's footprint reaches 2 billion sf, with 7 billion sf in the pipeline
About 7 billion more sf of commercial space is expected in the pipeline.
| Aug 30, 2012
Georgia drops LEED wood source standard on state projects
Currently, LEED green building standards only accept timber products certified by the Forest Stewardship Council (FSC).
| Aug 21, 2012
AGC offers second edition of the Federal Government Contractor: Ethics & Compliance Programs manual
This publication helps contractors appreciate the grounds for an alleged violation of the expected standards of business conduct and ethics, and to develop, implement, and document an effective ethics and compliance program.
| Aug 21, 2012
Federal Safe Building Code Incentive Act’s bipartisan support, no notable objection, bodes well for passage
The Safe Building Code Incentive Act would give states a little extra post-disaster federal funding if they enacted and enforced nationally recognized building codes for businesses and residences before disaster strikes.
| Aug 16, 2012
New York’s Barclays Center project accused of ignoring noise, pollution regulations
Construction crews racing to finish the Brooklyn Barclays Center are ignoring strict regulations to reduce noise and pollution, a new report by critics has found.
| Aug 16, 2012
Harness saves life of worker cleaning Washington state Capitol
Fall-protection equipment helped save the life of a worker who was cleaning the Washington state Capitol building in Olympia, after the platform he was using gave way.
| Aug 16, 2012
CSI webinar on August 21 focuses on electronic energy control
The Construction Specifications Institute (CSI) is sponsoring a free webinar on August 21 at 2:00 p.m. (EDT) on electronic energy control.
| Aug 16, 2012
Public sector pushes sustainable building forward
Not usually noted for its innovation, the public sector has done the most to advance sustainable building, according to a recent panel of green building professionals.
| Aug 16, 2012
Canada’s first net-positive building under construction in Milton, Ontario
The GreenLife Business Centre in Milton, Ontario near Toronto is set to become the first net-positive energy building in Canada.
