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Commercial HVAC, Preventive Maintenance Agreements

IAQ Alert: Is Your HVAC System Contaminated?


When you think about the potential dangers that could threaten your building and its occupants, your HVAC system may not immediately come to mind. Many companies are prepared for natural disasters and terrorist threats, which, although potentially devastating, are statistically unlikely to happen. Yet companies fail to consider the much more likely threat of indoor air quality (IAQ) problems such as an accidental chemical or biological contamination spread through the building’s HVAC system.

With some advance planning and regular maintenance of your HVAC system, you can prevent many IAQ threats entirely and avoid the worst outcome from accidents.

What IAQ contaminants could your HVAC system spread in your building?

Because your HVAC system circulates air throughout the building, it has the potential to spread many types of contaminants as well, including:

  • Viruses and bacteria
  • Mold and mildew
  • Fumes from chemicals being used in the building
  • VOCs that are released from many modern building materials
  • Smoke
  • Carbon monoxide
  • Asbestos
  • Refrigerant gas

The most common IAQ threats come from biological agents, which are almost certainly present in your HVAC system if you haven’t kept up with regular cleaning and maintenance.

Viruses and bacteria can cause outbreaks of colds but also more serious illnesses such as measles, influenza, tuberculosis, Legionella, and most recently, Covid-19.

Mold and mildew growth, which are common when a building’s humidity is not properly controlled, will cause breathing difficulties in people with allergies and asthma, and can also cause skin problems. The growth of microorganisms in a building’s ventilation system can even spread a potentially serious respiratory illness called “humidifier fever.”

Contamination from chemical agents, including carbon monoxide and asbestos, are less common IAQ threats but often deadly when they do occur. If your air conditioning system develops a major leak, the release of refrigerant can cause skin damage, frostbite, and blindness and asphyxiation.

How do IAQ contaminants get in there?

Contaminants can be introduced into your system from a variety of sources:

  • Negligence and poor maintenance of your heating, air conditioning and ventilation systems
  • Droppings from rodents, cockroaches and other pests
  • Accidental chemical spills inside the building (a major threat in factories and laboratories)
  • Airborne contaminants from the surrounding area, possibly resulting from a roadway or rail accident, plant malfunction, or fire.
  • Natural disasters
  • And yes, even deliberate criminal or terrorist activity.

7 steps to eliminate HVAC contamination

With so many potential threats, how can you keep your building, and more importantly, its occupants, safe and secure?

Fortunately, there are some simple steps you can take to avoid contamination of your HVAC system. By properly planning your system’s design, and being vigilant about regular maintenance, you can mitigate IAQ risks and prevent many dangers entirely.

1. HVAC system maintenance

Start with the easiest solution and the one with a guaranteed impact: regular cleaning and preventative maintenance of your HVAC system. When you establish a service contract with an HVAC service professional, they will regularly clean your equipment, change filters, clean ducts and grates, and calibrate controls and devices that detect gas leaks. These simple actions prevent the accumulation and spread of biological and chemical contaminants in your system.

2. Improve filtration

Install higher efficiency filters, which prevent the spread of contaminants by trapping particles and keeping them out of the ventilation system.

3. Monitor contaminant levels with IAQ testing

Install monitors with visual and audible alarms to alert you to high levels of toxic substances in the air, including carbon monoxide, VOCs, and other chemicals.

4. Review ventilation design

Ventilation design controls airflow within your space, and the right design can help remove microbes, VOCs and more to improve IAQ. Especially if toxic chemicals are used in your building, ask your HVAC contractor how the ventilation system can be engineered to help contain fumes in the event of a spill.

5. Prioritize vulnerable occupants

Consider who is in your building, and where the most vulnerable occupants are located. For example, if you have children or seniors in the building, who are more quickly harmed by contaminants, pay special attention to the design and maintenance of the ventilation in those areas.

6. Take advantage of automation

If you have a building automation system that controls the systems and air flow in your building, make sure it is programmed to shut down parts or all of the ventilation system in the event of a chemical or infectious disease contamination.

7. Don’t overlook HVAC security

Determine where your system might be vulnerable to a deliberate attack, and take steps to secure those areas. For example, restrict access to the roof and wherever air intakes are accessible. Try to avoid air intakes at ground level whenever possible. Secure any areas of your building where HVAC equipment is located.

None of us likes to think about the dangers we might face, so we often neglect preparation for the most likely threats of all. How many of us worry about dying in a plane crash, but then fail to wear a seat belt in a car? It’s those small actions we do day in and day out, like buckling up even in the back seat, that keep us safe and prevent disaster.

Keeping your building safe from HVAC contamination is no different. The planning and safeguards you put into place can improve IAQ and help minimize damage in the event that the worst does happen. But the easy steps you take on a regular basis, such as cleaning and maintaining your system, have the biggest impact. Not only do these steps protect your building’s occupants from illness and discomfort, but they also give you the peace of mind that comes from knowing that you’re safe from the most common IAQ threats.

Interested in learning how investing in a service contract for preventative maintenance can keep your building healthy and also save you money? Download our guide to HVAC Preventative Maintenance Contracts.

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