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 7, 2014
Ohio legislature moves to bar LEED standards on state projects
The use of LEED standards is being barred for public construction in Ohio under a state senate resolution.
| Jan 31, 2014
Center for Environmental Innovation in Roofing releases solar panel racking criteria for asphalt shingle roof systems
The Center for Environmental Innovation in Roofing’s PV Taskforce is releasing the first public draft of PV Racking and Attachment Criteria for Effective Asphalt Shingle Roof System Integration for an initial round of public comment.
| Jan 31, 2014
Developers are exceeding LEED standards for marketing purposes
Using LEED certification as a marketing tool is perceived by developers to be a successful tool, and this has pushed them to go above the minimum requirements at each level of certification, according to a study in the Environmental Science & Technology journal.
| Jan 31, 2014
OSHA extends feedback period for disclosure of workplace injuries proposal
The Occupational Safety and Health Administration said it would extend the comment period for a proposal that would require employers to submit electronic reports of workplace injuries and illnesses.
| Jan 31, 2014
DOE releases new efficiency standards for halide lamps
The Energy Department has finalized new energy efficiency standards for metal halide lamp fixtures, which are used in lighting for big box stores and parking lots.
| Jan 31, 2014
New LEED online platform now available for LEED v4 projects
LEED v4 projects will be the first to experience the new LEED Online platform with streamlined documentation and processes.
| Jan 26, 2014
New York extends, enhances tax abatements to promote green roofs
The expansion of a tax-abatement program for green roofs under New York state law doubles the previous maximum benefit of $100,000, adds new plant species to the list of those applicable for the tax break.
| Jan 23, 2014
Washington state micro apartment law prompts fire safety concerns
Proposed legislation to further regulate the building of micro apartments has triggered appeals from community activists concerned that fire safety standards are sub-par.
| Jan 23, 2014
Pennsylvania owes school districts $1B for construction projects
The Pennsylvania Department of Education owes about $1 billion to numerous school districts for about 350 state-approved renovation and construction projects.
| Jan 23, 2014
About 1,500 concrete buildings in Los Angeles found vulnerable to earthquakes
Some 1,500 concrete structures built in Los Angeles before 1980 could be vulnerable to earthquakes, according to University of California researchers.