Alexandra Hospital Meets Codes, Saves Energy with Duct SealingVicki
When administrators at Alexandra Hospital received testing and balancing (TAB) reports indicating that the building’s HVAC system was not providing sufficient rates of air exchange, they called in Nerva Duct Sealing for recommendations. With duct leakage at the heart of the problem, Nerva found options limited: either upgrade the entire system or manually seal the ductwork. Both operations were prohibitively expensive and disruptive. With much of the ductwork hidden behind walls and covered in insulation, the cost of manual sealing was estimated at more than $1 million. And that didn’t even include the cost of the demolition and reconstruction necessary to access the ducts. Then Nerva – a building efficiency company always on the lookout for industry innovations – suggested the hospital consider using a new duct sealing technology that works from inside the ducts to find and seal leaks. The unique inside/out approach of aeroseal duct sealing would provide easy access without demolition and was a fraction of the cost of other options. Best of all, it was highly effective. Nerva also found the technology had been successfully used at other hospitals in Canada, the U.S. and around the world.
- Building: Alexandra Hospital
- Location: Ingersoll, Ontario, Canada
- Aeroseal Contractor: Nerva Duct Sealing
- Goal: Increase HVAC air exchange rate
- Before Aeroseal: 18,550 CFM of leakage
- After Aeroseal: 1,484 CFM of leakage; 92% reduction
- Results: Increased air exchange rate to meet regulations while reducing fan speeds and other energy-consuming HVAC functions by an average of 30%; $59,000+ annual savings from reduced energy usage; $29,000 in utility rebates
Alexandra Hospital in Ingersoll, Ontario, Canada uses duct sealing to meet codes and increase energy savings.
Given the go ahead to aeroseal the ducts, Nerva first conducted a full audit of the HVAC system. The amount of air coming out of each register was measured, and the energy required to operate the three main air handling units and the one exhaust system included in the first phase of the project was calculated. In less than two weeks, sealing was completed, and post-testing found that aerosealing the ducts increased CFM output by an average of 27%.
With the higher rate of air flow, Nerva is able to replace the constant fans with variable frequency drives (VFD) and other equipment that will reduce overall energy usage. Post-seal measurements show that VFDs will cut fan energy usage almost in half. Chilled and hot water usage through the coils will be reduced by 27%, which reduces the load on every air handling unit by 27%. The steam boiler’s output for each air handler will also be reduced by an equal amount. Detailed modeling reveals an annual energy savings of $59,321.
The administrators at Alexandra Hospital approved the sealing project to resolve test and balance issues, but, with the help of aeroseal technology, found a way to cut their energy bill by more than 30% – enough to pay for the entire project in less than five years. As a bonus, the project generated $29,000 in utility rebates.
“Within the first night of sealing, the CFMs that were leaking out of the system were restored, and the leaks were 90-95% sealed, so we were able to move all that extra volume of air throughout the departments the way the system was designed. Going in (with aeroseal) was less invasive, and the time it took to seal was cut to 1/3 of the projected time it would have taken to seal manually. Using aeroseal was a ‘no brainer.'”
Head of Maintenance
“Nerva is all about employing the newest and greatest innovations that allow us to improve the efficiency of our clients’ buildings. Whenever you can tell a hospital administrator that you are going to reduce their chiller and boiler operations by 25%, you will be golden. This represents 30% of a hospital’s overall operating costs.”
Nerva Duct Sealing
About Aeroseal Technology
- Developed at Lawrence Berkeley National Laboratory in 1994.
- Research for aeroseal technology was partially funded by the U.S. Department of Energy.
- Aeroseal is the only duct sealant technology that is applied from the inside of the duct system. It is delivered as a non-toxic aerosol mist that seeks out and plugs leaks.
- Aeroseal has proven to be 95% effective at sealing air duct leaks.