A+ to Nerva Duct Seal technology from Jadwin Hall at Princeton University

Duct sealing technology proved effected even on old unlined masonry shafts where leaks were responsible for exhaust issues and high energy bills.


98% leak reduction


Jadwin Hall


Princeton University


Reduce leakage in two exhaust shafts

Before Sealing

533 CFM leakage

After Sealing

8 CFM leakage

A five year, $70 million dollar renovation of the University’s Department of Physics building focused primarily on upgrading the 6-story structure’s 50-year-old HVAC system. While most of the ductwork was replaced, this was not an option for two of the main exhaust shafts, which were part of the building’s structure itself. Significant leaks in these shafts were making proper air system balancing impossible. That, in turn, caused exhaust issues and added substantially to the building’s energy consumption. University engineers knew that Nerva Duct Seal was highly effective at sealing metal ductwork, but could it actually seal leaks in old brick masonry shafts?

The only other option would be to take out sections of the masonry to access the leaks and then rebuild the structure – a process that would have been extremely expensive and disruptive to the daily operation of the institution’s department of physics. Classes were in session and the labs were filled daily with students and University personnel engaged in activities.

University engineers did some initial prep work for the sealing project before a aerosol sealing team came in the morning to begin sealing.

As we looked at options for Jadwin Hall we decided the building was still viable and worth investing in rather than going to the expense of constructing a completely new facilities… It worked quickly and effectively to solve a potentially project-derailing obstacle. I imagine there are other campus projects that could use this technology as well.

– Aric Duvalla, Assistant Facilities Supervisor Princeton University.

The entire project took two and a half days to complete; setup, sealing two shafts and pack up. The results were immediate. The incredible sealing reduced the masonry shaft leakage by 98% – from 533 cubic feet per minute (CFM) to 8 CFM. As a result, exhaust issues were resolved, energy usage was reduced and system balancing was accomplished – all without interruption to the building’s day-to-day function.

I took a special trip to the project site to see this new technology at work for myself. It was exactly as described in our research reports. It worked well. No glitches. No Issues. I would definitely consider using this in future projects where we can’t get access to the ductwork.

– Dan Sabatino Contract Manager Irwin Leighton Inc.