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
| Mar 22, 2012
Bill would reintroduce “opt-out” provision in lead paint law
The Lead Exposure Reduction Amendments Act of 2012 (S2148) would restore the "Opt-Out" provision removed from the Environmental Protection Agency's Lead Renovate, Repair and Painting (LRRP) rule in April 2010.
| Mar 15, 2012
New Florida building code establishes flood and storm surge provisions
The new 2010 code establishes minimum design and construction requirements to protect buildings from wind, rain, floods, and storm surges.
| Mar 15, 2012
Illinois city rejects international code due to home sprinkler requirement
Macomb, Illinois aldermen voted to recommend that the city not adopt 2012 international building and residential code standards requiring the installation of overhead sprinkler systems in newly constructed one-family and two-family homes.
| Mar 15, 2012
Tenant advocates propose licensing landlords in New York City
With thousands of New York City rental units posing potential dangers to tenants, city advocates are proposing measures to make landlords improve building safety.
| Mar 15, 2012
Construction industry a big winner in federal small disadvantaged business procurement
Last year, only 5% of federal contract dollars went to small disadvantaged businesses. Construction and facilities support firms were the biggest beneficiaries.
| Mar 15, 2012
ANSI approves new fall protection standards
The American National Standards Institute (ANSI) has approved two American Society of Safety Engineers' (ASSE) standards addressing fall protection.
| Mar 8, 2012
Engineering innovation provides new option for meeting seismic codes in skyscrapers
Two University of Toronto engineers have developed “viscoelastic-energy-dissipating dampers” to replace many of the heavy concrete beams used in tall structures.
| Mar 8, 2012
CSI webinar on building code compliance March 22
A March 22 webinar will provide an overview of a 28-step process during the design of a building to ensure compliance with building codes.
