The coronavirus outbreak will not end overnight, and the economy will gradually reactivate as the number of cases drops. There are many viable measures to reduce COVID-19 transmission in buildings, but they can backfire when used incorrectly. To achieve the best results, building owners should follow the guidance provided by industry authorities like ASHRAE and the US Green Building Council.
Building managers can address COVID-19 with a combination of safety protocols and technical measures. ASHRAE recommends increased ventilation with outdoor air, while upgrading filters and adding ultraviolet disinfection. The US Green Building Council is providing guidance based on LEED, while expanding the certification with new credits that help prevent COVID-19. Similarly, the International WELL Building institute (IWBI) has published guidance based on the WELL Building Standard v2.
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This article will summarize some common mistakes when trying to prevent COVID-19 infection in buildings. These mistakes may seem like good prevention measures at a glance, but they are actually harmful.
Using Ventilation Controls With Their Normal Settings
The term “smart ventilation” can be misleading, and what is considered smart under normal conditions may not apply for emergencies like COVID-19. Ventilation systems are normally configured to provide just enough air for the building, but not more. Many facilities use demand controlled ventilation (DCV), where the outdoor airflow is adjusted according to occupancy. This saves fan power by reducing the air supply, and the heating or cooling needed to bring that air to a suitable temperature. However, reduced ventilation is not recommended when dealing with an airborne pathogen.
Ventilation controls are very useful, but they should be reconfigured for the coronavirus emergency. ASHRAE recommends as much outdoor air as possible, regardless of occupancy, while reducing indoor air recirculation. This helps dilute and remove viral particles from the air, reducing the risk of COVID-19 infection. However, if a DCV system is reducing airflow all the time, viral particles can reach a higher concentration.
DCV systems should be disabled temporarily, and ventilation equipment should be configured to supply as much outdoor air as possible. This can be accomplished more easily when a Building Automation System (BAS) is available. The normal configuration can be saved and disabled, and a new configuration can be set for COVID-19 prevention.
Using Ozone-Based Disinfection Systems for Occupied Spaces
Ozone is generally viewed as a “good” gas, since the Earth’s ozone layer blocks harmful radiation from space. However, the same cannot be said of ground-level ozone. Normally, persons with healthy respiratory systems will only experience shortness of breath and lung pain when exposed to ozone. However, the gas is more dangerous for patients with conditions like asthma and bronchitis, since they can experience aggravated symptoms.
Some disinfection methods use ozone directly, since the gas is capable of destroying bacteria and viruses. However, these methods should only be used for empty spaces and inanimate objects. Ozone is also a byproduct of some ultraviolet disinfection systems, particularly those with a wavelength below 200 nanometers. Before purchasing a UVGI system, make sure it meets the UL 2998 Standard - Environmental Claim Validation Procedure (ECVP) for Zero Ozone Emissions from Air Cleaners.
Ignoring Other Dangerous Germs in Building Interiors
The new coronavirus (SARS-CoV-2) is receiving plenty of attention from the media, but building owners should not overlook other biological hazards. Uncontrolled humidity can lead to a mold infestation, damaging materials and releasing spores into the air. These spores can cause allergic reactions, and patients with respiratory conditions are especially vulnerable.
The Legionella bacteria is even more dangerous than mold: it causes Legionnaires’ disease, a severe pneumonia with a much higher fatality rate than COVID-19. This bacteria tends to grow in stagnant water, especially when it has remained warm for extended periods.
Building owners should deploy prevention measures for coronavirus, but they cannot ignore mold and Legionella. Managers should be especially careful when reopening buildings that have been occupied for several weeks, since mold and Legionella could have spread undetected. Getting a professional assessment of your building is recommended before reopening.
Using Unsuitable Air Filters
ASHRAE recommends upgrading air filters to capture viral particles more effectively. However, you should not purchase the highest filter rating available without an HVAC assessment. High-performance filters capture small particles more effectively, but they also restrict airflow. Ventilation systems should have enough capacity to handle the new filter, or the airflow may drop to unacceptable values.
The most efficient air filters are those with a MERV rating of 13 to 16, and HEPA filters can trap an even higher percentage of fine particles. If your ventilation system cannot operate with these filter ratings, they are also available as portable units. You should not use an air filter that will choke your HVAC system, since indoor air cannot be renewed effectively.
Trying to Resume Business as Usual
COVID-19 has been disruptive for all business sectors, but it also provides an opportunity to improve efficiency in business practices. For example, many companies were forced to use remote collaboration for the first time, to continue operating during government lockdowns. However, they have realized that many tasks do not require the physical presence of collaborators. Remote collaboration prevents COVID-19 infection during the emergency, but it can also improve efficiency under normal conditions.
Construction technology (contech) is a promising field, but the industry has been slow to adopt innovative solutions. The COVID-19 outbreak provides a chance to test new concepts and prove their effectiveness, achieving a permanent benefit for the construction industry.