The population density in high-rise offices forces physical contact in elevators. Direct contact with surfaces infected with viruses is unavoidable. Centralized air conditioning blows viruses into the office, and the viruses can then circulate in an enclosed area. Personal hygiene precautions are vital. Outdoor air intake can reduce virus infection rates in buildings but need hospital-grade filtration to remove harmful particles. Wang Yuke reports from Hong Kong.
The COVID-19 pandemic has upended prior conventions of open-plan and high-density workplaces. A safety radius between workstations, plus plexiglass partitions, personal masks, frequent hand washing, hand sanitation dispensers, temperature readings, and avoiding coughing or sneezing in the open are preventive hygiene disciplines to inhibit the spread of viral infections.
“Hot-desking” is another idea being dumped to reduce viral infections from multiple access to common facilities. Viruses survive on human-touch surfaces for days, and spread through subsequent human contact. Work-at-home and video conferencing allow staff in the digitally connected world to virtual-meet anywhere, anytime.
Virtual meetings
Zoom is a widely used virtual conference platform for companies and educational institutions. Security of data privacy is a concern, which the company has assured will not be compromised in the United States and Europe. Hong Kong-based International Interior Design, launched its BenQ Interactive Flat Panels, for collaborative virtual meetings to share notes and presentations on a virtual whiteboard, like a physical meeting.
Virtual conferencing requires adequate bandwidth to work efficiently. Most capital cities are now broadband enabled, although at peak hours that may be strained as video consumes bandwidth capacity. The frequent-travel jockeys from Hong Kong need not mount airlines so often. Flight and hotel expenses can be cut, while companies save space by rostering staff between home and office.
Meanwhile, the suitability of tiny shared flats in cities like Hong Kong and Tokyo, as alternative work spaces, cannot be assumed. It is likely that junior staff take their laptops to Starbucks or similar social locations with broadband availability. Cities with suburban extensions and reliable public transport like Kuala Lumpur, Taipei and Bangkok, are less constrained in space for working from home.
Office space shrinks
Apart from flexible conference rooms for face-to-face meetings, the office of tomorrow will need only the minimum space for in-office staff and document storage. The impact of reduced demand for office space will be significant. Landlords will need to compete on “virus- proofing” buildings, air-quality systems, and frequent disinfection of elevator buttons and escalator handrails. Tenant health has become a major factor in leased spaces.
Apart from personal hygiene precautions, there will be a critical re-examination of building structures, closed loop air-conditioning, fresh air intake, and neglected restrooms. Millions of humans spend eight to 10 hours daily in these buildings. Some corrective measures are feasible to retrofit existing buildings — if landlords are willing. Companies can migrate away from those buildings that cannot be upgraded for infection control.
High-rise buildings need elevators to move people efficiently, but that totally defeats the precautions of social distancing and the risk of contact with viruses on public surfaces. Companies could move to suburban locations with low-rise, low-density buildings, at reduced rent.
Offices need to reduce human density. The empty spaces can be flexibly configured for individual workstations or team collaboration as required. The ideal would be an environment for individual autonomy and activitybased ergonomic culture.”
Dieter Kursietis, consulting director at Gensler Hong Kong, an architecture, interior, planning and strategic consulting firm
Dieter Kursietis of Gensler HK counsels on flexible workspaces for meetings, and rotation of staff on shifts, to reduce office density. He said such density is bad for infection risk and productivity. Kursietis predicts more “pods” will be installed in offices for virtual communications at workstations. Gensler has received many inquiries from multinational companies about workplace redesign to address virus infection risk. Social distancing in the office is likely to become a universal code of practice. Cushman & Wakefield, a real-estate services firm, introduced the “six feet rule” for each workstation to have a clear radius from co-workers. It uses directional signage so that employees keep a distance from each other of at least 6 feet (1.8 meters).
Outdoor air intake
Fresh air is vital to dilute the concentration of viruses and bacteria in buildings, to reduce the risk of infection. A 2019 study on influenza transmission by Pennsylvania State University, found that adequate levels of outdoor air ventilation can equate to having 50 to 60 percent of occupants vaccinated. In an influenza-virus experiment, scientists at the University of Maryland found the virus in 39 percent of aerosol samples, confirming that influenza can transmit through air circulation.
The common flu is a seasonal occurrence in Hong Kong, affecting thousands of adults and school children annually. The elderly and people with respiratory medical conditions are most vulnerable to poor indoor air quality, cautions Peter Cheung, research assistant professor in biomedical engineering at the Hong Kong University of Science and Technology.
Cheung references a recent study by Francesca Dominici at Harvard University, which found that a minor elevation of long-term exposure (even a 1 μg/m3 increase in concentration) to fine particulate matter (less than or equal to 2.5 micron) can lead to 15 percent death rate increase for COVID-19.
Mike Putnam, pre-construction manager at Unispace, an international company providing business and commercial interior design solutions, notes that an appropriate Heating, Ventilation & Air-Conditioning (HVAC) system has to balance occupation density, floor area, use of space, etc.
The American Society of Heating, Refrigeration & Air-Conditioning Engineers (ASHRAE) specifies a minimum outdoor ventilation rate of 20 to 30 percent. Its protocol for office space is a minimum outdoor ventilation rate of 5 cfm (cu.ft/min) per person or 0.06 cfm/sq.ft. Classrooms need 10 cfm per person or 0.12 cfm/sq.ft. Sports and entertainment facilities require a higher rate of 20 cfm per person.
Roberto Bruzzone, co-director at HKU-Pasteur Research Centre, School of Public Health at the University of Hong Kong, maintains that good outdoor ventilation is important for infectious disease control in our densely-populated city. Given the city’s vehicular traffic-polluted outdoor air, filtration of air-intake is especially critical. The filtration system has to be tuned to “viral load, distance between people, and time they spend together, which combined, determines transmissions,” notes Bruzzone.
Effective filtration
A building air-filtration system removes dust, pollutants, viruses and bacteria. “Without an air filter, efforts to control air quality for occupant health are pointless, as the viruses and bacteria circulate in the air, to infect more victims,” said Wong Tze-wai, adjunct professor of the JC School of Public Health and Primary Care, at the Chinese University of Hong Kong. Wong has conducted extensive research into infectious diseases, environmental and occupational health. “The more fresh air coming in, the better,” Wong said. “We have engineering standards for interior design, on indoor temperature, humidity, and air current speed, ... but these standards are mostly designed for occupants’ comfort, not to control viral infection risk,” he added.
The amount of fresh air in most indoor areas in Hong Kong is low. Introducing more fresh air will increase the energy load of the air conditioning. It’s a costly practice, which private building owners are reluctant to invest in.”
Wong Tze-wai, adjunct professor of the JC School of Public Health and Primary Care at the Chinese University of Hong Kong
Douglas Newkirk, design director at Gensler HK, said the firm has received inquiries to improve ventilation in toilets and common areas. Newkirk said that in older buildings, a single ventilation system serves all stalls in public toilets. “The ideal is to have independent ventilation for each cubicle,” Newkirk said. Research has indicated that the “toilet plume” generated after flushing spreads infection via aerosol particles through the air and into air-conditioning circulation. Virus-infected feces and vomit are particularly dangerous, he said.
While air filtration systems are nominally available in modern commercial buildings in Hong Kong, John Goudie of Goudie Associates, one of the partners of the Savvi Design and Build Platform, said they are mostly inadequate. “Many independent air-conditioning systems have more effective filtration of harmful particles.” The Savvi platform uses data and artificial intelligence to match off-market options for tenants, with landlord and agency partnerships.
HEPA standard
Unispace follows the Minimum Efficiency Reporting Value (MERV), a scale designed by the ASHRAE to assess the efficiency of air filters. Putnam references the international high-efficiency particulate air (HEPA) standard. A HEPA certified air filter must remove at least 99.97 percent of particles 0.3 microns in diameter.
The HEPA standard is used for contamination control in the manufacture of disk drives, medical equipment, semiconductors, food, nuclear plants, and pharmaceuticals. It also applies to homes, vehicles and hospitals. After COVID-19, the filtration for office space is raised to MERV 13 or higher, closer to healthcare filtration, Putnam said.
The coronavirus can be transmitted in droplets exhaled from an infected person, through coughing, sneezing, and talking, as virus-laden fluid smaller than 5 microns. It can linger in the air for up to three hours.
Portable air purifiers come in handy at this particular time, especially welcome in small offices in Hong Kong. A floor-standing air purifier invented by Aurabeat, a startup in Hong Kong Science Park, works using silver ion, plasma and ultraviolet technologies. The company said it can eliminate the coronavirus and 99.99 percent of bacteria, with effective coverage ranging from 40 to 50 sqm.
IAQ guidance
The government’s guidance for green buildings stresses the importance of indoor air quality (IAQ) as “people spend more than 70 percent of their time indoors.” The guidance recommends two major approaches for better IAQ — adequate ventilation, and control of the source of indoor air pollutants.
Click to find out more about IAQ
The government launched an IAQ Certification Scheme for Offices and Public Places in September 2003 to encourage property owners and management to implement IAQ guidelines. It is voluntary and few have responded. “There is a lack of enforcement,” said Alex Yeung, founder of Bravolinear, a company specializing in air purifying technologies. He said incentives are not enough, and that the IAQ should be mandatory for new buildings.
The Asia-Pacific Economic Cooperation body found that only 7 out of its 21 member economies had mandatory regulations pertaining to IAQ — the Chinese mainland, Taiwan, Japan, South Korea, Vietnam, New Zealand, and Mexico.
Antiviral treatment
Human contact of public surfaces contributes to respiratory pathogen transmissions, Bruzzone said. A University of Arizona study in 2014 showed a single contaminated doorknob or elevator button could spread viruses to 60 percent of other sampled surfaces — such as light switches, countertops, coffeepot handles, faucet handles, and computer equipment — within two to four hours.
Surfaces repeatedly touched should be given special coating or finishes of materials with antimicrobial properties like copper, silver and brass. They can also be woven into fabrics, such as carpets and upholstery. However, treatment with such antimicrobial materials is expensive, said Albert de Plazaola, Unispace’s global strategy leader. “You have to use it tactically, and sparingly,” he said.
More-economical alternatives are smooth and nonporous materials that are easily cleaned. “Antibacterial or antimicrobial plastic and polyurethane, for instance, can withstand heavy cleaning and disinfection,” de Plazaola said. Chan of Goudie Associates added that roll-out mats are preferable to carpets for building entrances and lobbies as they better trap viruses and dirt, and withstand frequent cleaning.
Smart technology
“How can we save lives through smart technology?” Newkirk of Gensler asked rhetorically. “Touchless elevators, wave-motion entry doors, touchless faucets, automatic doors in bathrooms, touchless coffee-makers controlled via mobile apps, touchless lighting sensors...” Radio-frequency identification chip-embedded ID cards can allow contactless security screening, he said. “Hong Kong people have privacy concerns over facial recognition technology,” Newkirk said.
“If you find touch-free technology too costly, you may consider hands-free,” Newkirk said. Infrared rays at the door can detect the temperature of people before opening automatically, or foot paddles can fling the door open.
Ultraviolet light is a potential agent to sanitize viruses in office workspaces. However, there is no international standard for optimal light intensity, duration, and how spaces underneath desks, on the floor, and in bookshelves can be effectively sanitized by ceiling UV lighting, he said.
Contact the writer at jenny@chinadailyhk.com
