Summary
- It is impossible to track the actual pathogens in the air
- A combination of air quality and air flow monitoring can provide a very clear picture of how safe a space is
- Implementing guidelines and monitoring are insufficient. To attract tenants, this data must be presented through real-time dashboards
Ever since ASHRAE stated that “transmission of COVID-19 through the air is sufficiently likely that airborne exposure to the virus should be controlled” And that “changes to building operations, including the operation of HVAC systems, can reduce airborne exposures,” the race has been on to understand what can and should be done.
As is human nature, a lot of attention has been paid to alternative and emerging “silver bullet” technologies such as bipolar ionization, ultraviolet light, dry hydrogen peroxide, disinfection filtration systems, and portable air filtration. But as usual, it is the constant application of the fundamentals that is having the biggest effect across the industry.
By now, every owner and operator is familiar with the guidelines to increase outdoor air ventilation, control temperature and humidity control more precisely, upgrade particulate filtration, deploy portable HEPA room air filters, and utilize ultraviolet germicidal irradiation (UVGI) where possible.
These measures, while critical, have proven insufficient for commercial real estate. This is not because they are ineffective, it’s because simply implementing guidelines in the background hasn’t been enough to make tenants comfortable to return to buildings.
As such, real-time indoor air quality monitoring has been a major focus over the last few months. In practice, this is easier said than done. Here are the lessons Enertiv has learned deploying a range of sensors across office, multifamily and industrial assets.
1. Particulate Monitoring is Not Necessary
The truth is, there is no silver bullet to air quality monitoring. Despite some claims in the market, it is simply impossible to track pathogens in the air.
The naked particle size of the coronavirus is approximately 0.1 microns. The best commercially available particulate matter sensor on the market can only track particulates down to 0.3 microns. More importantly, the virus typically attaches itself to other small particles such as aerosols that can be anywhere from 0.3 to 10 microns as well as large droplets which are typically 10-20 micros.
Basically, particulate matter sensors alone provide many false positives because even the smallest particles may not be the virus. Likewise, there is a high risk of false negatives; large droplets that would appear too big to be the virus could be carrying the virus.
What is this spike due to? Can we conclusively say that this particulate matter contains COVID-19? Of course not.
That doesn’t mean that this data is useless. It can be a powerful indicator if combined with other sources.
2. Couple Air Quality with Air Flow
One of these critical supplemental data streams is HVAC performance, specifically air flow. This is calculated by tracking the temperature and humidity within air handling units to ensure that the targeted supply and return of outdoor air is being achieved.
This is critical because many systems were sized for a different purpose than is required under with COVID-19. It’s easy for an operator to change equipment settings, but without seeing the data on what effect that is having, there’s no way to verify a safe amount of outdoor air.
In addition, units working harder than originally designed leads to more frequent faults and breakdowns. In a time when equipment uptime is critical to keeping tenants safe, the status quo of discovering these issues during routine preventative maintenance is insufficient. Instead, mechanical and electrical performance data can alert operators the moment a fault occurs to reduce the time to repair and increase overall uptime.
Air flow monitoring, combined with traditional indoor air quality metrics such as carbon dioxide, provides a complete picture about the air quality within a building and tenant space. Again, this does not track COVID-19 particulates directly, but it allows operators to mimic the outdoors as close as possible, which has been shown to dramatically reduce transmission.
3. Tenants Need to See to Believe
It’s clear now that the government stating that the economy is reopened doesn’t necessarily translate to individuals deciding to come back to the downtown apartments or return to the office.
Implementing guidelines and measuring indoor air quality and air flow will only go so far if kept in the back-office. Owners need a way to communicate with tenants that the air quality in their space is improved and will be maintained at a high level.
The best way to do this is with visible dashboards in the building lobby and through tenant portals. Compared to signs posted and email communications that state what is being done, real-time dashboards do not require any trust, all the information a tenant could need is right there. Ideally, these visualizations are setup to provide high-level green, yellow, red indicators and the ability to dive into detail measurements if desired.
4. Corrective Measures
Data is the foundational first step that allows operators to understand what effect their changes to HVAC operations and filtration are having on the indoor environment. But when the data indicates there’s a problem, what is supposed to be done as a corrective measure?
Well, that depends on the problem. One of the most important lessons learned so far in the pursuit of maintaining a safe indoor environment in the time of COVID-19 is mapping specific issues to specific corrective measures.
Here’s an example:
ConditionCorrective MeasureWorsening baseline IAQ metrics, steady HVAC air flow performanceReplace filtersSteadily worsening air flowCheck seal perimeter of all filters inside air handling unitsQuick drop in air flowCheck outside air dampers, adjust setting higher than minimumOutside supply air consistent, return air steadily worseningConfirm exhaust connections are tightHVAC pump off for more than 24 hoursRun HVAC pump to maintain circulation
There are dozens more, but the point is that numerous things can go wrong with indoor air quality and responding to those, especially with the limited staff available in many properties, can be difficult without this precision.
5. Unintended Consequences Can be Managed
Making significant changes to the operations of a building will necessarily bring unintended consequences around sustainability and occupant safety. However, there are strategies, aided by real-time data and software, to effectively manage these risks.
Running systems longer and harder to bring in more outdoor air is already causing energy costs to go up, undercutting sustainability goals just as it is becoming a key performance indicator for many organizations. While this is an inescapable fact of running systems outside of their designed parameters, and replacing systems is out of the question for properties with already stretched budgets, there are measures that can be taken.
First, digitize preventative maintenance. This may sound unrelated, but the National Center for Energy Management and Building Technologies concluded that effective scheduled maintenance, such as cleaning tubes in centrifugal chillers, ensuring condenser flow rates, maintaining proper refrigerant levels, purging refrigerant of oil contamination, fixing leaks in compressors, repairing broken economizers, measuring airflow, and maintaining thermostats and sensors could decrease energy bills by 15 to 20 percent in commercial buildings.
Combined with other measures like continuously analyzing HVAC schedules and equipment startup and shutdown times using real-time data can more than offset the increases due to COVID-19 prevention.
On the other end of the spectrum, there are real, non-COVID-19 risks coming to light due to the prolonged shutdown of building systems, particularly cooling towers and domestic water systems. In fact, the CDC itself had to close several of its own buildings because of Legionnaire’s disease concerns.
Many commercial real estate operators are aware of this risk and implemented corrective measures early in the pandemic, including:
- Clean hot and cold water coils and condensate drip pans
- Drain, flush and thoroughly sanitize cooling towers
- Run all HVAC pumps each day to maintain circulation of chemical treatment
- Flush domestic hot water systems
But with the continuing uncertainty about occupancy rates, these need to be consistently applied. The best way is to achieve this has been with checklists based in mobile apps. This digitization not only ensures that operators have one screen to manage their work, but their usage can be rolled up into management dashboards.
Conclusion
There have been numerous lessons learned about monitoring indoor air quality since it has come into focus due to COVID-19.
While the disease itself cannot be monitored, there are low-cost and easily implemented strategies that can be deployed to not only significantly improve the indoor environment, but to demonstrate as much to tenants.
As commercial real estate portfolios and technology vendors continue to translate learnings into solutions, indoor air quality will translate directly to financial health of the portfolio.
Enertiv has developed the only comprehensive COVID response solution that combines air quality, air flow and people flow. Schedule a demo today to see how it works!
.webp)
.webp)
