Page 39 - spaces4learning, Spring 2021

HVAC Downtime Can Be Avoided
For ventilation to remain adequate for our indoor environ- ments, the HVAC equipment responsible for that ventilation simply cannot break down. HVAC systems have evolved to im- prove efficiency and give us better control over environments, and those systems have multiple components that should be properly cared for to avoid issues—from compressors and coils to variable-speed fans and high-efficiency filters.
Since the COVID-19 pandemic, standards organizations ASHRAE and the CDC have both stressed the importance of in- creasing ventilation to reduce pathogen counts in shared spaces. Their recommendations include discontinuing the use of demand controls that may reduce ventilation and increasing airflow to spaces when occupied. Taking these steps may increase the load on an HVAC system, and a poorly maintained system is less equipped to stay operational and efficient under those conditions.
Guidance on increasing filtration for HVAC systems also notes that increasing filter efficiency can lead to reduced airflow. Compensating can increase energy use as fans and components work harder. A poorly maintained system is also in danger of responding inadequately to those needs.
When the System Is the Problem
A poorly maintained HVAC system can itself be a source of indoor pollutants. Filters, air ducts, cooling coils, and drain pans are all examples of failure points where lack of attention can introduce unwanted contaminants.
Imagine a food safety inspector asking why a restaurant’s kitchen is so filthy, and the owner responding, “Well, we cleaned it when it was built.” The food we eat shouldn’t be produced by a contaminated system, and the air we breathe
PHOTO CREDIT ELNUR
shouldn’t arrive through one.
Poorly maintained cooling coils, drip pans, or cooling
towers have been found to be the cause of respiratory diseases (like legionnaires). According to one estimate, the interior surface area of air ducts is 10% of the floor of office spaces, and dust accumulation there can promote the growth and release of micro-organisms and metabolic products into the air.
Just Open a Window?
When indoor ventilation breaks down, simply opening a window may feel like a great temporary fix. However, not every facility has this option, and the sad truth is that exposure to outdoor air car- ries risks that we’re also continuing to learn about. A Stanford-led study from 2021 found that children’s exposure to outdoor pollut- ants, even for only a single day, led to changes in gene expressions that impacted their long-term chances of heart disease.
Limited access to outdoor air is also a problem during a facility’s response to indoor pathogen spread. In recommen- dations for reducing exposure to SARS-CoV-2, the virus that causes COVID-19, the CDC noted that opening windows could reduce the concentration of viral particles inside. That recommendation is hedged with important caveats, however, such as to use caution in highly polluted areas. In fact, the CDC goes on to recommend, “Ensure ventilation systems operate properly and provide acceptable indoor air quality for the current occupancy level for each space.”
It’s Not All Downside
Studies show that improving indoor air quality has positive effects. A 2015 study found that enhanced ventilation, includ- ing reduction in volatile organic compounds, led to increased cognitive performance scores and improvements in information usage and crisis response. Enhancing ventilation may increase an HVAC system’s load, but a well-maintained and optimized system can help a facility deliver the benefits of improved indoor air quality in a cost-effective manner.
The Time Is Now
Given the health risk that poor indoor air quality poses to the people who share the air in our facilities, it may be time to con- sider HVAC a mission-critical asset. The first step in improving the indoor air quality in our facilities is ensuring that ventilation meets or exceeds the clear guidelines for airflow. Keeping those systems running optimally may be a cost, but when compared to the risks of poor ventilation passed on to the people in our facilities, the benefits of proactive maintenance are clear.
Kevin Brown is the Vice President of Engineering for ABM. He is a member of ABM’s Expert Advisory Council, which is com- posed of leading experts in infectious disease, industrial hygiene, and facility services, and he advises on many aspects of ABM’s business, including the company’s proprietary EnhancedCleanTM and EnhancedFacilityTM programs. He serves on the board of the Energy Management Association (EMA) and several technical and standards committees for the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE).
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