Treat the Building’s Ventilation System Holistically

As part of our ongoing Problem Solved series, Habitat spoke with John Twomey, co-founder and chief executive at Indoor Air Quality Champs.

The problem. It's pretty alarming to see, but in about 95% of the buildings that we enter, the ventilation systems don't work. Which is scary, because these systems are the lungs of your building. They’re designed to keep you safe.

We find that you have to look at the building holistically — at all the components together. The main issue that we find are breaks in the continuity of the system. Everything needs to be sealed tight or else it's not going to work. So while there are not a lot of components, the few that are there need to really be sealed up tight and work together in order for the whole system to function properly.

The components of the system. We have an exhaust fan, a vertical exhaust shaft, and the branch ducts that go into the units and the common areas that need to be ventilated. If the ductwork and the exhaust shaft are not sealed correctly, then the system is not going to work as designed. It's going to pull air from other areas at these unintended leakage locations.

A case study. I'm currently working at a 16-story, postwar co-op in the West Village. We’re actually the seventh ventilation contractor called into the building by the co-op board to try to correct their improper and inadequate airflow.

The previous contractors just weren't thorough enough. They didn't make sure that the unintended leaks were addressed. We’re still finding all sorts of issues that should have been addressed with the first contractor, maybe by the second at the most. But to be the seventh contractor and still be finding some of these issues — it's alarming because it’s not that hard to understand how to correct this. You just need thoroughness. You need to find all the openings where air is being drawn from unintended areas.

This building was built in 1966. It has vertical exhaust shaft risers, what we refer to as discontinuous exhaust shafts. They build them floor by floor, and there’s a cut in the sub-floor between every story. At these areas, the vertical exhaust shafts were not sealed properly to the sub-floors. So the farther you go down, the more air the fans are drawing from these unintended gaps. By the time you get halfway down the building, the air that’s meant to be pulled from these units has already been exhausted through the interstitial spaces to several areas where it shouldn't go. And that's all because of these unintended, unsealed leakage locations.

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The heightened importance of air quality. It's sad but true, but it took a pandemic to bring indoor air quality and ventilation as a whole up to the front of people's minds. But it's always been an issue. There's still a ton of things moving between apartments if the airflow of the building is uncontrolled — mold, asbestos fibers, stuff like that — that are meant to be exhausted from the building. We've been screaming from the top of our lungs, "This needs to be dealt with!" But the pandemic has definitely brought it to the forefront.

To sum up, you’ve got to treat these systems holistically. You need to address it from the exhaust fan on the roof all the way down to all the connections in all the areas you intend to ventilate. If you don’t, the system is never going to work properly.