Kaiser Family Foundation (KFF) reported that, as of mid-August, coronavirus had contributed to more than 70,000 deaths of senior living residents and staff. People in long-term care facilities make up 8% of coronavirus cases, yet 45% of all COVID-19 deaths.
Long-term care facilities seemed to see some reprieve from the virus, with their share of coronavirus deaths becoming relatively constant through the summer months. However, in mid-August cases began again to increase, demanding that these facilities’ managers take new steps to adapt buildings to keep residents and staff safe through the predicted surge to come. MEP design considerations can play a significant role in keeping seniors safe.
While there may be another COVID-19 surge coming in the winter season, facilities managers are now better armed with insight on how to adapt their buildings to keep occupants safe. Taking action on the four MEP design considerations described below today can reduce the risk of viral transmission in the months to come.
Extensive research indicates that lower humidity levels promote the airborne transmission of all kinds of viruses, making humidification one of the biggest influencing factors on the spread of disease. The current research indicates that low relative humidity (RH) has a significant impact on the transmission of airborne droplet of all sizes, as well as viruses’ ability to survive outside of a host carrier. Midrange RH levels—within a range of 40% to 60% RH—are the most effective at neutralizing the virus’s ability to survive long enough to infect another person. RH levels also impact the human respiratory system’s ability to fight off viral infections.
The best method for distributing humidity throughout these occupied spaces is through the use of add-on systems for the central HVAC systems. These add-on systems generally rely on the generation of clean steam, which is injected into the airstream in the supply air ducts or HVAC equipment through in-duct distributor units.
By examining MEP design considerations, as well as monitoring and control factors, senior living facility managers can ensure their buildings’ HVAC systems provides the most economical and powerful means of keeping humidity levels within the desired range for infection control.
Proper ventilation is a critical factor in maintaining acceptable indoor air quality. The better the supply air mixes with the air in the occupied space, the better the chances are that any airborne contaminants will be carried back to the HVAC unit, where they can be trapped within an air filter or rendered inactive by air cleaning methods installed within the unit.
Ventilation effectiveness is largely dependent upon how well the HVAC system has been designed, but even in existing facilities, relatively minor revisions can improve a system’s ventilation effectiveness. However, research indicates that ventilation effectiveness can drop significantly in the heating mode, due to reduced airflows and stratification of the air in the space.
What’s more, increasing ventilation rates beyond code-required levels can also lead to some unintended consequences if not implemented properly—most notably, a drop in thermal comfort and inappropriate RH. This adjustment can also substantially increase a facility’s energy costs. Energy recovery ventilators can reduce the burden of increased ventilation air and its energy costs. Properly designed ventilation systems can actually improve both infection control and building efficiency.
Appropriate filtration can help capture infectious viral particles and remove them from recirculation in the air. The challenge here is that many infectious particles are extremely small in size. The SARS-CoV-2 particle measures only 0.12 microns in size. That’s why it is important to use a filtration media that is rated to capture these smallest particles. A minimum MERV 13 rating would be required to achieve even a 50% capture rate for particles under 1 microns, while a MERV 16 filter rating is required to achieve a 95% capture rate.
Not all HVAC systems are able to support higher rated filters. While the first step should be to install the highest MERV rated filtration media possible, consider in-room filtration units to provide an additional layer of protection for seniors.
While staff should already be disinfecting visible, high-touch surfaces in accordance with CDC guidelines, HVAC systems may also benefit from disinfection technologies. Germicidal UV (GUV) systems are one solution for this. GUV is a time-tested technology that has proven effective at killing viruses, bacteria and fungal organisms in healthcare and other settings.
The challenge to effective GUV is in ensuring those particles are directly exposed to UV rays of sufficient power and duration. To achieve airstream disinfection, UV-C lamps should be installed within the main supply air duct to disinfect air as it passes through. Some facilities opt to combine HVAC GUV and upper-room GUV with fully automated room decontaminators or portable, self-contained air cleaners that incorporate GUV in their operation.
As knowledge around the SARS-CoV-2 virus evolves, so too will our best practices. However, there is clear evidence that MEP design considerations can significantly impact viral transmission.
Now is the time for senior living facilities managers to conduct a thorough facility analysis and ensure that all systems are functioning to their maximum potential. Improvements to ventilation, humidification, filtration, and disinfection will result in better infection control even after the COVID-19 pandemic has passed.
If you’re looking for an experienced partner to assist in this work, contact Schnackel Engineers today.
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