California Hospital Uses Aeroseal Duct Sealing, Per Engineer SuggestionAndrew at Aeroseal
The UCSF Medical Center at Mount Zion has a pharmacy with two ventilating hoods that require sufficient exhaust or else a fail-safe system will register a malfunction and equipment will automatically shut off. This pharmaceutical facility is where chemotherapy chemicals are prepared, so it is critical that all airborne particles be exhausted from inside the hoods via connecting ductwork that leads outside the building. Even after meticulous construction with manual duct sealant (e.g. mastic, tape) applied to all 300 feet of twisting ductwork, the exhaust system was simply not providing enough pull to meet duct leakage specification or to keep the HVAC system running properly.
- Building: UCSF Medical Center at Mount Zion
- Location: San Francisco, California
- Engineer of Record: Interface Engineering
- General Contractor: TCB Builders
- Aeroseal Contractor: Coast Environmental
- Goal: Meet sufficient exhaust for two ventilating hoods (ductwork) in the hospital pharmacy and improve HVAC system performance
- Before Aeroseal: 580 CFM of leakage
- After Aeroseal: 23 CFM of leakage
- Results: Sealed ductwork to 96% reduction in leakage; Met duct leakage specification for pharmacy to have proper functioning of the ventilation hoods
Over a two-month period, the contracting team could not find the source of the leakage. The exhaust ductwork, covered in fire insulation, was unwrapped, manually resealed and rewrapped. With the building’s scheduled opening fast approaching, the design engineers assisted the contractor in identifying the area of potential leakage. Working collaboratively, the contractor and design engineer performed several tests that narrowed the largest source of leakage to a particular section of ductwork. The challenge with this section is that it was above the congested ceiling of an occupied section of the hospital making it difficult to manually seal. When the contractor described the challenges associated with the particular section of ductwork, Interface Engineering had suggested using Aeroseal as a method to seal the leaks without having to work in the congested ceiling area. Interface Engineering was confident that the Aeroseal process would seal the leaks better than trying to find the leaks in the congested area. At first there was a fair amount of pushback against the Aeroseal method to sealing air ducts (a.k.a. “fix-a-flat” for ductwork).
With no time left for a test run, hospital administrators gave Coast Environmental, a duct and IAQ specialist, the green light to clean and seal the air duct system using Aeroseal. The Aeroseal sealing process took just forty minutes to complete (20 minutes for each of the two sections of ductwork being sealed), and the entire process was conducted without interruption to the hospital’s regular 24/7 operations.
Using Aeroseal, the contractor could actually watch holes and cracks in the ductwork getting sealed in real-time. A computer-generated chart showed a plunging line on the Aeroseal computer screen representing the real-time decrease in leakage. After two months of trying to find the leaks and seal them by hand, the contractors had their leaks sealed using Aeroseal in only 40 minutes. Best of all, the new pharmacy opened on schedule.
Robert Gaderlund, Project Manager, UCSF Medical Center at Mt. Zion: “We were hesitant to use Aeroseal. We didn’t know if it would work or not. We weren’t even sure that leaks were the issue. All we knew was that the new ventilation hoods weren’t functioning properly and we were running out of time. So we proceeded on the advice of a trusted consultant familiar with the technology…and it worked beautifully. It quickly sealed the leaks and fixed the problem.”
Rick Schaffel, General Contractor, TCB Builders, San Francisco, California: “We tried adjusting the fans, resealing the ductwork and various other solutions. Duct leakage kept us from getting sign-off on the project. In the end, it took twenty minutes to seal the outside ductwork and another twenty minutes to do the rest. Aeroseal worked. It was a real project saver.”
Adrian Welsh, Duct Specialist, Coast Environmental, Carlsbad, California: “It turned out to be a perfect solution to finding and easily sealing all of the holes and leaks throughout the entire duct system. I love how you can actually see the progress and know it’s working.”