Aeroseal Keeps The Peace – And Air Flowing At St. Alban’s
There are always three sides to an argument, or so the saying goes: your side, the other side, and the right side. As it turned out for the various contractors involved in the renovation of St. Alban’s Anglican Church, the right side proved to be Aeroseal duct sealing.
To look at it from the street, you wouldn’t believe that St. Alban’s Church, resting majestically on a small hillside in downtown Ottawa, actually offers the area’s homeless a warm and comfortable respite from cold Canadian nights. But within the structure’s 2-foot thick stone exterior, you’ll find a recently renovated facility that offers a host of modern comforts, from newly installed bathrooms and showers to kitchen facilities, daycare and sleeping rooms. Perhaps most importantly, the church now offers visitors the warmth and comfort generated by a newly installed energy efficient heating system – a significant upgrade for the 147-year-old-building.
Before the renovation took place, St. Alban’s 4,000 sq. ft. basement was used primarily for storage. A boiler system ran hot water to the upstairs where radiators generated heat for the entire building. As part of the modern overhaul, the basement was transformed into a community shelter and the boiler system was updated and augmented with an ERV (energy recovery ventilations) unit.
“The church decided that if they were going to update the heating system, they ought to do so with energy efficiency in mind,” said Dan Carley, project manager, Dolyn Developments Inc. “The ERV system takes the heated air that is already inside the building and combines it with treated outside air and distributes it through new ductwork we assembled and placed along the basement ceiling. The ERV is also connected to the exhaust system, which is used to keep the upstairs and downstairs bathrooms and shower areas ventilating properly.”
On paper, everything looked right. The ERV was specified to provide 1,000 CFM of output, more than enough to heat the building and ventilate the kitchen and bathrooms. But when all the components of the system were put in place, and the power switch to the ERV was turned on, clearly something wasn’t working right. The ERV wasn’t doing its job and ventilation was still poor at best.
“From the balancing reports I saw, it was clear that the ERV wasn’t drawing in enough air or blowing out enough on the other side,” said Bert Lelievre, duct specialist, AWS Remediation Technologies. “Even when the ERV was turned up as far as it could go, there was simply not enough air on either end.”
That began the year-long head scratching, testing, and tweaking process to figure out what wasn’t working right.
One obvious possibility was that the ERV system wasn’t functioning properly. Over a period of several months, the system was examined, adjusted and tested. The system was rebalanced and retested. The supply handlers were examined and tuned. And the ERV system was retested again. Nothing. The project had stalled. Without the ERV working properly, the building wouldn’t get the ventilation or heat that was needed and the entire renovation project was heading to failure. The contractors were baffled. The suppliers were exasperated. The church administrators were frustrated.
“There was a lot of finger pointing and lots of conjecture as to who was to blame for the problem,” said Carley, “And while the issue of duct leakage was raised during discussions, no one believed that simple leaks could have such a dramatic impact on results, so for a long time, it was ignored by everyone.”
At wits end, Carley and his crew at Dolyn decided to see what duct sealing would do. They spent several days manually sealing what they could reach using tape and mastic and then retested the system. There was little if any substantive change.
“I knew that the manual duct sealing would only address a small portion of the entire duct system. Most of the ductwork was very close to the ceiling or behind newly constructed drywall where we couldn’t reach it,” said Carley. “If we wanted to properly seal the duct system, we would have to tear down the walls and pull off the ductwork completely – basically start from the beginning – a prospect that was devastating on a number of levels. Then someone from the team mentioned Aeroseal.”
Several of the contractors had heard about aeroseal technology but no one had first- hand experience with this new approach to duct sealing. After researching the technology, Carley thought it was worth trying.
“There was an awful lot of skepticism to go around,” said Carley. “I reviewed a number of case studies where the technology was used in hospitals and laboratories so I knew it was safe. But it was hard for me to imagine that aerosealing would make all that much difference.”
Still, at this point, aerosealing was the fastest, least expensive option left to pursue. After discussions with the engineering team and others, Dolyn Developments called in Lelievre and the folks at AWS.
“We came down to the church and reviewed the problem,” said Lelievre, “and after reviewing the various reports, we were confident that Aeroseal was the answer. We see this type of problem all the time and know how effective aerosealing can be. Most people simply don’t realize the impact that duct leakage can have on either ventilation or the proper balancing and operations of an HVAC system.”
With the paperwork completed and system schematics reviewed, AWS came in at noon on a Tuesday, had the Aeroseal hose connected to the ductwork by 3pm and were wrapped up and on their way home by 8pm that same evening. Once they finished, a tester came in behind to balance the system. The airflow to the ERV was clearly much stronger than before, so he turned the unit down to a more appropriate level and went home for the night.
Anxious to see the results, Carley and the other contractors arrived in the morning to test the system. You can imagine their reaction when they couldn’t get the ERV unit to function properly.
“The system just wouldn’t turn on and operate as it should,” said Carley. “We began to make calls – to the tester, to the ERV manufacturer, to anyone we could think might have a clue. It was then that we figured out the problem. With such a significant increase in airflow to the unit, the tester had turned down the ERV so low that it wasn’t kicking on by itself. We just needed to turn it up a bit and then everything was running like a clock.”
Now the church is providing energy-efficient heating to its congregation and effective ventilation for its bathrooms and kitchen. It would never have been possible without proper duct sealing – and that required Aeroseal.
“I’m a believer,” said Carley. “The numbers speak for themselves. Before aeroseal, we were loosing about 665 CFM of air through duct leaks – that’s about 2/3rds of where we needed to be for proper system functioning. Aeroseal reduced that leakage rate 93%, giving us well over the amount of air needed. Before Aeroseal, we were operating the ERV at full force and not getting enough airflow. After Aeroseal, we set the ERV to about ½ its operating power and still got about 20% more air than we needed. That’s a huge difference – in both system functionality and in energy cost savings.”
It’s been about three months since St. Alban’s Church has opened its newly renovated facilities to the public. The new daycare facility is full of children and the shelter is providing room and board to some of the city’s most needy. With the help of Aeroseal, the church is saving money on energy costs, the kitchen and bathrooms are fresh as can be, and at night, everyone is sleeping warm and comfortably.