Barb Checket-Hanks

Several weeks ago, the small community I live in experienced what some might call an extraordinary event. An accident and fire resulted in the release of toxic chemicals in an area with multi-family housing, schools, single-family houses, and small businesses. The American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) has a specific definition for extraordinary events, but they really boil down to unexpected occurrences that can cause the quality of outdoor air to worsen rather quickly and dramatically. These events can include fires (and the resulting smoke), chemical releases, and chemical and biological attacks. The society has spelled out how to manipulate ventilation systems in such cases.

These guidelines were developed shortly after the terrorist events surrounding 9-11, including airborne contaminants and anthrax contamination. Their broader usage, however, offers very practical information for events that can occur by accident, such as the case in my own hometown. Fortunately, I wasn’t close enough to the chemical release to be required to evacuate. We had concerns, however, because we own birds; the “canary in a coal mine” analogy came to mind. That afternoon I also had time to ponder just how drafty my home really is.


Luck was on our side that day. The winds were not blowing in our direction, and in fact they were not particularly strong (which would have made the fire harder to fight and spread the contaminants farther and more heavily). Despite the intense heat, our fire department (with assistance from a neighboring community) was able to put out the blaze before more storage tanks ruptured. But I realized just how vulnerable many communities are to accidents like this, especially in densely populated regions like Southeast Michigan.

I need to give credit to our fire department. They were obviously well prepared for such an emergency scenario. It was obvious to me that they had a plan, and thank goodness for that. Perhaps it was even a part of our community’s Homeland Defense preparedness. The one thing missing, from my observation, was information in the community on what they should do to decrease their air intake.

Common sense should let people know that they should shut their windows and doors, but how many people knew enough to shut off their house fans or air conditioners? How common is common sense? I saw children playing outside that afternoon; even though the wind was not blowing in our direction, I know that their size would make them more susceptible to ill effects if winds shifted and the chemicals blew our way.

My husband and I know where our leaky spots are. We did the best we could with tape and towels until the imminent danger was declared to be over. We also shut down the house fan. But as little as that may have done for us, it was still much more than our neighbors were aware that they could do to protect themselves.


Is there an opportunity for the HVAC community here? I think there could be. Of course we don’t want to be fear mongers, but offering advice on preparation for extraordinary events might be something that sets your company apart from others. The information might prove useful for local newspapers if you are looking to become a reliable media resource.

Some of today’s ventilation systems offer options that can give building owners even more options in the case of such extraordinary events. The Multi-Aire balanced ventilation system, for instance (featured in the Sept. 28 issue ofThe NEWS) can introduce fresh, filtered air into the home, balance air pressure, and pull air out of the house.

Two models can be used for either positive or negative air pressurization. For those customers whose thermostats can be accessed remotely, either by phone or online, they could shut down the ventilation system if one of these events occurs while they are away from home.

Even if your customers don’t have more advanced IAQ systems, you could still advise them on the basic steps to take to minimize the amount of contaminated outdoor air entering the home. Don’t be afraid to be too basic: Tell them to shut their doors and windows. Then include information on how to shut their HVAC systems. Check out the information on extraordinary events at

If an event involves the air that enters the building, it’s not out of line for you to offer information on how the system affects it. You could be doing a real service to your community and customers. At least, you might help calm a neighbor’s fears.

Publication date:10/26/2009