It’s simple – HVAC units that are under constant stress fail.
The ongoing COVID-19 pandemic has caused facility management personnel of commercial and education buildings across the nation to make a lot of adjustments to their HVAC systems. But what some may not realize is that if their HVAC systems were already strained due to deferred maintenance, the COVID-19 adjustments could cause system failure.
At the recommendation of the USA’s CDC, many facilities managers brought more outdoor air in to keep CO2 levels down, therefore improving filtration in their systems. While intended to dilute the concentration of the virus in the air, this process often increases PM2.5 pollutants, reduces air flow, and puts a tremendous strain on the system itself.
Introducing more outside air can dilute the concentration of the airborne COVID-19 virus that would otherwise accumulate due to the exhaled air of people with the virus. Diluting infected air is a good thing, which is why so many facilities managers are doing it. Unfortunately, though, bringing in more outside air also greatly increases humidity and particulate matter PM2.5. Increased moisture means more mold. More particulate matter — including dust, pollen and other contaminants —clogs filters and fouls coils, and can also create breathing problems for those with respiratory issues.
The other half of this equation is filtration. In an effort to reduce the circulation of the COVID-19 virus, building managers have increased the MERV of their filters. It is true that more virus molecules would be trapped by the more restrictive filter, but less airflow means it takes longer for the amount of air in a room to be exchanged for clean, filtered air. Also, HVAC systems need a minimum amount of airflow to remain effective at controlling temperature and humidity. In the end, their efforts may lead to increased humidity and mold, and higher concentrations of virus-laden air than before.
As if that wasn’t bad enough, try layering these issues on top of a system with deferred maintenance, meaning important maintenance activities have been delayed or skipped altogether. Most often this is done to cut costs, but in reality, seemingly harmless omissions like not changing filters or cleaning the air handling unit, coils and ducts, can seriously reduce the efficiency of an HVAC system and weaken it altogether. A lack of maintenance can result in restricted airflow and increased coil static pressure. Gaps in the filter housing or worse, holes in the cabinet itself, can follow.
Holes and gaps in an HVAC system allow particulate matter to enter the air handlers and build up on internal components — the walls, blower motor housing, drain pan, and especially the evaporator coils. When coils get dirty, airflow and static pressure are again compromised, making it harder to regulate the temperature and humidity in the building.
The buildup on internal parts causes dampness, which becomes a food source for bacteria and fungi. When microbes spread, so do foul odors, mold spores and allergens. In those conditions, building occupants could suffer from headaches, sinus congestion and eye irritation. It is not surprising that recent studies from Harvard University and the State University of New York found a correlation between indoor air quality (IAQ) and cognitive functions. This adds up to losses in productivity and an increase in sick days.
Something else to consider is that HVAC systems affected in this way are going to be running more hours of the day to try to control increased temperature and humidity. This means mechanical parts will wear out and break down faster, and a lot more electricity is going to be used to run them – both results can immediately increase costs for a building owner. However, increased energy consumption also expands a facility’s carbon footprint, which is harmful for the environment in the long run.
It’s simple – HVAC units that are under constant stress fail. Motors running longer wear out belts, bearings and bushings. Clogged drain pans overflow and cause structural damage. Wiring might overheat or short circuit which could result in fires. Cooling lines crack and leak. This causes flooding with a chilled water system. In a condenser system, cracked lines cause refrigerant leaks that present a safety issue to occupants.
Each of these scenarios create major disruptions to operations, not to mention the steady stream of work orders and additional costs to fix them. In the end, combining the results of COVID-19 adjustments with HVAC systems that have delayed their maintenance can be a double blow that some systems will fail to recover from.
The first thing to do is get your HVAC system and building assessed by a certified and credible IAQ professional. Find out the environmental and mechanical condition of your facility’s HVAC system now. The same professional can recommend what to do to help your system recover and then maintain it.
Next, ask them how to handle increased outside air and increased filtration recommended by the CDC to combat COVID-19 conditions. The HVAC professional will know the limits and capacity of your system and will be able to optimize its performance with methods that might include steam cleaning the evaporator coils. Other prescriptive suggestions may include supplemental technology like UVC, needlepoint bi-polar ionization or strategically placed air purification units that can reduce the concentration of virus-laden air without overtaxing the system.
Utilizing data-driven science, a certified and credible IAQ/HVAC professional will be able to help you reduce costs, fight the COVID-19 virus, and make your facility a healthy and productive work environment.