Ask an expert at Southland: COVID-19 and engineering

Peter Pobjoy at Southland Industries shares details on what engineering changes may lie ahead with COVID-19 issues

By Peter Pobjoy, PE June 24, 2020

Have building owners or clients approached you to assist with changes or updates to their building to help protect against COVID-19? What services can you offer?

Peter Pobjoy: Our first conversation with owners starts off by explaining that the HVAC systems are not the sole focus of mechanical, electrical and plumbing engineers, as the virus transmission is more likely to take place within the occupied space between people rather than be transferred there by the HVAC system. There are many published recommendations, but we believe that while they may mitigate the chance of spreading the virus, they are not going to prevent it from spreading when the virus is present.

Owners are interested to know about any technology that can assist with managing their building systems to be more resilient and be best prepared for the current and any future pandemics. We are first recommending that building owners do a facility condition assessment (FCA) to understand exactly what systems are in place, the condition and what recommissioning work needs to take place to correct performance. Following the FCA, we recommend outlining a menu of options with associated cost and energy impact.

This can range from strategies around limiting contact to HVAC modifications. It really depends on the building use, existing systems and current state before recommending a wide variety of measures. A thorough analysis of the building with existing data and modeling with the use of computational fluid dynamics will serve the owner will in evaluating the best path forward.

What HVAC, test-and-balance or air balancing challenges have you encountered? What unique challenges are you solving?

Peter Pobjoy: ASHRAE, the Centers for Disease Control and Prevention and World Health Organization, among others, have published position papers in reaction to the current pandemic. With regards to HVAC, there is widespread opinion that the HVAC system is not a main contributor to the spread of the disease within the building because the droplets that carry the disease are too heavy to be transmitted throughout the HVAC but rather, are transmitted directly within the space where people are congregating.

That being said, the idea to increase ventilation through both additional outside air and with additional air changes may mitigate the spread to some extent. Disengaging demand-control ventilation controls is one aspect that will help maintain higher outdoor ventilation rates in addition to running systems beyond normal occupancy periods up to 24/7. Taking this action will increase energy consumption and that is one challenge owners will face as they balance occupant health with operating costs.

Before a building owner makes any changes or modifications to existing systems, they should first verify that the systems are correctly balanced and delivering the airflow in accordance with the design. This would include airflow quantities, pressure relationships, leakage and directional airflow.

For hospitals and health care facilities, do you anticipate demand for specialty or pressurized environments? What else is changing in these buildings?

Peter Pobjoy: Currently, the only approved method of containing a patient with a virus such as COVID-19 is to place them in a negative pressure isolation room, which meets the criteria of a vestibule, single pass air, alarms, etc. What was evident in the early stages of the pandemic was there were insufficient quantities of these space types in acute care hospitals. As hospitals evaluate the planning of their facilities, I would expect to see more negative pressure rooms including potentially larger spaces up to an entire building floor designed to accommodate critical care patients with highly infectious diseases.

“Containment pod” prototypes are also being developed to allow for the transportation of a patient through a noncontained area.

From an engineering standpoint, what other markets or building sectors do you anticipate will grow due to the changes occurring due to the coronavirus? Is there a new engineering sector you plan to focus on to meet these needs?

Peter Pobjoy: Resilience of a building and related systems will have an added dimension in dealing with a pandemic such as the current COVID-19. This will require an integrated approach rather than traditionally looking at MEP systems individually, including not just MEP but the building infrastructure as a whole. We see experienced teams that understand the planning aspects, energy performance and environmental health working together to design buildings to meet the new challenge.

As more data becomes available from institutions such as ASHRAE and the Centers for Disease Control and Prevention with more definitive conclusions on how the virus behaves, we are certain that manufacturers will be developing products with added performance that may include sterilization and filtration as standard components.

Author Bio: Peter Pobjoy, PE, is Senior Vice President at Southland Industries in Garden Grove, Calif.