COVID-19: Getting Back to Business Roadmap
Relative View on Returning to the Workplace
As data shows that the New York Metro area has flattened the curve and past the very worst of the crisis brought about by the COVID-19 pandemic, society and business are reopening. Being mindful that SARS-CoV-2, the virus causing COVID-19 disease, is still very much active and circulatiang in the community, building owners and operators must become knowledgeable about making the safest, most effective, and most cost-effective decisions regarding how to adjust our work environments to decrease the risk of exposure and make a safer workplace for employees.
Here are the facts that matter the most in our buildings:
- Social distancing is an effective method to minimize exposure1
- Removing the pathogen is effective in reducing infection rates2
- Relative humidity below 40% depresses human immune response and causes the virus to persist in the air – this is why you get sick in the winter3,4
When we look at mitigation strategies that align with the facts, they fall into three categories:
- Social distancing – from A/B scheduling of employees to floor markings
- Hygiene – disinfecting surfaces, hand washing, etc.
- Building infrastructure – filtration, ventilation, humidification, UVGI lighting, and indoor air quality monitoring
The CDC, WHO, and other healthcare organizations have placed great emphasis on the first and second strategies. While these options are very effective, they are hampered by inconsistency in individual behavior, perception of risk, and individuals’ inclination to act responsibly.
When we return to the office, it will be difficult to remain completely unexposed. And when this happens, we will only have one contingency – our immune systems’ ability to fight back.
For this reason, we must focus on indoor humidity levels. There is no single greater impact building owners can make than providing an indoor environment maintained above 40% relative humidity. Sustaining this one measure can significantly reduce the spread of the virus on particles traveling in the air and is the only factor we control that directly influences our body’s immune response – and ability to defend itself.
When the COVID-19 pandemic extends into the fall and winter of 2020, and you cannot maintain an indoor relative humidity above 40% in the workplace, you may want to reconsider returning your workforce to the office.
HVAC | Make Sense of Your Investments
When it comes to our HVAC systems, we have some opportunity to make our work environments safer. Current industry and regulatory guidelines do exist and are focused on two things: increasing ventilation and increasing filtration. While these two recommendations make sense in isolation, they can have devastating impacts on your occupant’s health as well as your energy cost, but those consequences go unnoticed until you look at the indoor environment holistically.
Increasing filtration probably makes the most sense. Filtration can remove the pathogen itself – fact #2 above. However, higher effectiveness in your filters typically means more fan energy consumption and lower overall airflow. Both of these consequences need to be analyzed to find the correct balance, and alternative methods can be considered such as UVGI lighting.
Increasing ventilation also makes sense in isolation – the solution being dilution – but this is arguably the most dangerous modification you can make because it is the one that leads to lower relative humidity. The higher the amount of cold air you bring into your building and heat up, the lower your relative humidity will drop. You must offset this by humidifying, or you will be weakening everyone’s immune system within your building. In addition to low humidity, conditioning outdoor air can be costly. Without performing an upfront analysis, opening your ventilation dampers to let in outside air can make for an unsafe indoor environment and cost you operational money in the process.
The playbook we recommend ensuring you understand the CAPEX, operational cost, and potential impact you will make with building-readiness measures before you implement them is as follows:
- Humidifier installation, reconfiguration, or recommissioning to minimize transmission capabilities of airborne germicides in low humidity environments by maintaining relative humidity above 40% when the building is occupied.
- Central air handling unit testing will include air flows, filter differential pressure, supply fan power consumption, ventilation rates, air change rates, and identifying existing filter specifications. Identify any potential filter upgrades along with the potential energy penalty.
- Custom programming to coordinate and maintain psychrometric conditions with the building as well as control ventilation, filtration effectiveness, and purging.
- UVC lighting as a viable option for inactivating viruses as well as keeping drains for coil drip pans clean.
- Positive pressurization of the building to the outside.
Occupant Perception | What You Cannot See
When we think about occupant perception, we may consider measures such as temperature checks at building entrances, occupant density, and social distance markings on the floor. This all makes sense, but the threat is in the air we live in and breathe.
We discussed some measures that will make that air safer for occupants, but how do we demonstrate that to our occupants? How do we show them how safe the air they are walking in, working in, and taking into their lungs is? There is only one way – demonstrate it.
Digital displays of indoor environmental quality is the one option we have to demonstrate the safety of the indoor environment to our occupants. A system comprised of monitoring stations and displays is the method to consider. Indoor air quality data and monitoring would also set a baseline for any of the more costly enhancements to your HVAC system as well. It is the logical starting point. Minimum readings would be CO, CO2, O3, PM 2.5, TVOC, temperature, and RH.
What Are the Industry Guidelines?
Our COVID-19 Back to Business services are based on industry guidelines, including the following strategic and practical guidance for COVID-19 transmission mitigation, education, and logistical implications:
- The Centers for Disease Control (CDC): Interim Guidance for Businesses and Employers Responding to COVID-19
- American Society of Heating, Refrigeration, and Air Conditioning Engineering (ASHRAE): ASHRAE COVID-19 Preparedness Resources
- For more industry specific guidance, ASHRAE summarizes their recommendations in presentations on:
- Occupational Safety and Health Administration (OSHA): Guidance on Preparing Workplaces for COVID-19
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