Can airconditioning control germ spread?
by Anne Ruth De la Cruz
The Novel Coronavirus. Covid-19. This is on everyone’s minds, and how everyone is going to great lengths to ensure the virus stays out of our bodies.
It is a scientific fact that dry air affects immunity and viral spread. And for the vital hospitals, factories, and offices that must stay open during the nationwide enhanced community quarantine, a key component to their effective functioning is the heating, ventilation, and air conditioning (HVAC) system.
A well-maintained HVAC system can play a significant role to prevent the spread of germs, while allowing critical processes to run successfully, according to Wilfredo R. Legaspi, general manager for HVAC, Lighting, and Auxiliaries of MSERV. A fully owned subsidiary of the Manila Electric Co. (Meralco), MSERV provides energy services and solutions, focused on electro-mechanical engineering, procurement, and construction (EPC) services, as well as energy-efficiency and urban services.
HVAC systems do more than provide cool, comfortable temperatures for doctors, patients, and workers. Many manufacturing processes and much laboratory work require precise temperature and humidity control, in premises that are dust- and germ-free.
“Proper and regular maintenance should be a priority,” Legaspi underscores, “so that HVAC systems perform according to their design.”
Viruses that cause the flu and the Corona Virus Disease (Covid-19) spread through droplets when people speak, cough or sneeze. At higher humidity levels, the droplets grow heavier, fall sooner, and travel shorter distances.
Too-low levels of humidity tend to dry out mucus membranes in the upper respiratory tract, which traps harmful particles before they reach the lungs. Rooms and buildings must, therefore, sustain a delicate balance for indoor humidity.
Fortunately, HVAC system design and maintenance are part of MSERV's expertise, Legaspi says, focusing on indoor air quality (IAQ) as the benchmark of a system's efficacy. IAQ addresses the basic areas of health, comfort, and energy efficiency.
To further germ-proof an HVAC system, he recommends the following:
- Bring in more outdoor air into buildings using HVAC systems. Outdoor air can dilute airborne contaminants, making infection less likely. This is the gist of “Your building can make you sick or keep you well,” by Dr. Joseph G. Allen, director of the Healthy Buildings Program at Harvard T.H. Chan School of Public Health.
Well-designed HVAC systems provide an essential control of humidity levels. When cold, dry air comes indoors and is warmed, the relative humidity indoors drops by about 20 percent. Virologists warn that such a drop in humidity makes it easier for airborne viral particles to travel.
- Enhance the level of filtration. Legaspi notes that buildings must be installed with filters that have a minimum efficiency reporting value rating of 13 or higher. This can capture more than 80 percent of airborne viral particles.
Filtered air conditioning systems in tropical countries like the Philippines are essential where patients or workers converge since high outdoor humidity can support viral spread.
- Use portable humidifiers to offset cold, dry conditions. Studies in mice suggest that a relative humidity of 40 to 60 percent is ideal for containing the Covid-19 virus.
This new research on the role of humidity in viral transmission is from a March 2020 paper published in the Annual Review of Virology by Professor Akiko Iwasaki, an immunobiologist at Yale University.
Iwasaki recommends the use of humidifiers in buildings where necessary. Her team’s related studies in mice found that an environment of 50 percent relative humidity contributed to good viral clearance and efficient immune response.
Legaspi says a temperature range of "22° to 26° C" at 40 to 60 percent humidity corresponds to decreased viral and bacterial infections. If an HVAC system cannot do so, he suggests portable humidifiers can be strategically placed in certain rooms.
- Regularly inspect and clean the HVAC system. MSERV guarantees that this will maximize energy efficiency; this also optimizes the systems’ ability to minimize the spread of pathogens.
Although manufacturers of industrial HVAC systems provide comprehensive installation services, Legaspi recommends having MSERV as part of the planning process for facilities.
“If there is a need to install an HVAC system, do it right from the very beginning,” Legaspi advises. This ensures that an HVAC system is properly supplied with power, to deliver cleaner and more efficient operation.
Story originally posted on Power Club.
To learn more, contact your Relationship Manager, call 16210 or email us at enterprise@meralco.com.ph.
