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
| Nov 18, 2011
New OSHA fall safety rule could save contractors money on insurance premiums
The new Occupational Safety and Health Administration rule requiring employers operating in the residential construction industry to use the same methods of fall protection that historically have been used in the commercial construction industry could save them money.
| Nov 18, 2011
Some believe new Austin building code will help mom and pop shops
Austin, Texas has proposed building codes that require wider sidewalks and call for buildings to be closer to sidewalks along a 3.5-mile stretch of highway.
| Nov 11, 2011
AIA: Engineered Brick + Masonry for Commercial Buildings
Earn 1.0 AIA/CES learning units by studying this article and successfully completing the online exam.
| Nov 10, 2011
WaterSense standard for weather-based irrigation controllers unveiled
The U.S. Environmental Protection Agency’s (EPA) WaterSense program has released a final specification for weather-based irrigation controllers—the first outdoor product category eligible to earn the WaterSense label.
| Nov 10, 2011
Advocate seeks noise reduction measures in California building codes
A former chief building inspector for San Francisco wants to enact building codes that would limit noise levels in restaurants and other spaces open to the public.
| Nov 10, 2011
California seismic codes spur flurry of hospital projects
New seismic requirements in California are helping to drive a flurry of new projects and retrofits in the state’s health care sector.
| Nov 10, 2011
Senate ready to repeal 3% withholding on government contracts
The U.S. Senate is set to approve legislation that would eliminate a law requiring federal, state, and local governments to withhold 3% of their payments to contractors and companies doing business with the government.
| Nov 10, 2011
New legislation aimed at improving energy efficiency in federal buildings
Recently introduced legislation, the “High-Performance Federal Buildings Act,” would help federal agencies save energy and money by improving building performance.
| Nov 4, 2011
CSI and ICC Evaluation Service agree to reference GreenFormat in ICC-ES Environmental Reports?
ICC-ES currently references CSI's MasterFormat and other formats in all of its evaluation reports. The MOU will add GreenFormat references.
| Nov 3, 2011
House Votes to Kill 3% Withholding Requirement; Senate Yet to Vote
The U.S. House of Representatives voted last week to repeal a 3% IRS withholding tax on businesses that do work for the government.
