BROOKFIELD, ILL. — The Chicago Zoological Park — better known as Brookfield Zoo — has been in business since 1934. The 216-acre campus sponsors numerous research and conservation efforts around the globe, and is home to more than 2,300 animals of more than 450 species.
In the past decade, the zoo has undergone significant capital upgrades. New construction has included a wolf habitat and a butterfly tent, while older buildings have been reconfigured into immersion exhibits, with animal collections grouped around ecosystems.
Hansen Mechanical has been in business since 1998, and Joe Hansen, as owner-operator, has cultivated a productive working relationship with Weil-McLain. They are one of the manufacturer’s go-to contractors in the area for unresolved issues, and Hansen has visited the company’s North Carolina facility to give feedback on new products and services.
“Mike Gambol, their commercial specialist called me up,” said Hansen. “He said that they were donating a couple of boilers to the Brookfield Zoo, and asked if I would be interested in installing them. I said we’d be happy to, that we could use the exposure, and it turned out great.”
Work by Hansen and his three- to four-man crews started in October of 2009 and finished in December. For both exhibits, Hansen Mechanical installed Weil-McLain’s Ultra 3 boiler, a new, commercial model of the company’s popular high-efficiency unit. In both cases, Hansen connected the new boilers to existing piping while leaving the original boilers in place.
“In the Living Coast exhibit,” Hansen explained, “they had about 4 million Btuh being delivered by three LBGs … in the summer time, they would be running just one of those guys on low-fire and it would be short cycling. We piped in the Ultra which has no problem handling the low-load times, which is about six or seven months out of the year.”
In The Swamp exhibit, the unit to be replaced was a gigantic cast-iron sectional boiler rated at 3 million Btuh.
“They were running that in the summer for domestic water only,” said Hansen, “and the heat exchanger was rated at just 600,000 Btuh, so they were firing this big radiator in the summer just to keep up their domestic water.”
Hansen expects the changeover to reap huge energy savings over the coming year. The biggest issue during the installation was the venting, which in each case was done with 8-in. PVC pipe.
“In one case we were able to sleeve it up through a chase and then out through a glass-block window,” said Hansen. “In the other we were in a room with an outside wall, and that pipe simply went up with the intake and the exhaust right above the boiler.”
Working in a zoo presented its own challenges. Access was at times limited; driving almost anywhere within the zoo perimeter required an escort, meaning the technicians couldn’t simply come and go as they pleased. Also, temperature tolerances were very exacting.
“It’s a critical environment,” said Hansen. “When you shut down a boiler, as soon as you lose 1½°F-2°F, the alarms go off. So the shutdowns had to be very quick and efficient. We had to do a lot of prep work before shutting down and draining the original system.”
On the upside, controls were a snap.
“They have quite an elaborate set-up,” said Hansen. “We just tied right in to the existing building automation center.”
Hansen is hoping that the energy savings the new boiler deliver will mean more work for him and his shop.
“They have a replacement schedule this year for about 20% of their boilers – and they have somewhere between 50 and 60 boilers at the zoo.”
Hansen has already placed two bids for the work.