Hartford Plaza
TRANE’S HYBRID HVAC SYSTEM PUTS BUILDING’S NEW OWNERS IN A BETTER SPOT
TRANE IMPROVES TENANT COMFORT AND OWNER’S INVESTMENT WITH SMART CHOICES
When a partnership between Lincoln Properties and Carlyle Realty bought the Hartford Plaza in downtown Chicago, they knew exactly what they were getting – the 31-story Building 150 built in 1970, and the 21-story Building 100 constructed in 1960…and location, location, location. They also knew they were getting an outdated, inefficient HVAC system and immediately began looking at options for upgrading or replacing it. The owners considered alternatives either to receive chilled water service from Exelon Thermal Energy, the local district cooling company, or to upgrade the chiller plants. They chose to upgrade and they decided to fast track it. “We obviously focused on the numbers and looked at it from an economic payback and equipment design standpoint. A new efficient chiller plant translates into higher net rents and improved tenant comfort,” said Tim Incerto, Lincoln Property’s General Building Manager. That’s where Trane comes in.
The new owners found that advances in technology and efficiency meant they wouldn’t have to construct two separate chiller plants; they could simply design one that would serve both buildings. The plant they specified consisted of two TRANE CenTraVac™ model CVHG multistage electric centrifugal chillers (one 1,250-ton, one 750-ton). The 750-ton machine is equipped with an Adaptive Frequency Drive to allow it to handle low-level cooling loads during colder months. A Trane single-stage absorption chiller rated at 1,000 tons was also included to utilize Building 150’s three existing steam boilers, which were in very good shape. All three chillers take advantage of existing permits to use the Chicago River for condenser cooling. The new chiller plant is also equipped with a TRANE UCP2 unit control panel which allows careful load monitoring, and takes extensive advantage of the system’s variable speed drives.
The new chiller plant has been a huge success on many levels. For the tenants, the drop in chilled water temperature from 48 degrees F to 42 degrees F provided better comfort and more effective dehumidification. The building’s managers gained better control over utility expenses. “Typically Norm (Norm DeSousa, Chief Engineer) makes the economic decision daily on how to load the chillers,” says Incerto. “Our new system gives us a lot of flexibility. Some days you only need one of the machines.” During warm summer days, they can choose to base load the large electric unit or the absorption unit and then bring the others on line as needed. “There’s no doubt that this combination chiller plant improves our negotiating position with energy suppliers,” said Incerto. “…the idea to go with a hybrid plant was clearly a winner….This solution gives us energy choices that other downtown buildings don’t enjoy.” There is something for the owners as well; Bill Denton from Trane Chicago summed it up well, “The efficiency benefit and the energy choice flexibility improved value for the building’s owners.” And that, as anyone can tell you, makes a smart investment.
|