rebate was critical not only to reduce
the cost of the project, but also as a
validation of the technical approach
from an objective third party. ComEd
provided a rebate of 50 percent of the
project cost, based on projected HVAC
energy savings of 26 percent.
The resulting net cost to ZRG was just
under $400,000, with an expected
payback period of about 22 months.
Given these economics, the team did
not have much trouble securing the
necessary capital approval. The installation work started in December 2014,
and 944 thermostats on all 65 floors
were retrofitted in about six weeks.
After two years of operation, the retrofit
has actually delivered better efficiency
than projected, reducing HVAC energy
use by 30 percent rather than the originally estimated 26 percent. The payback period was reduced to 19 months.
Hot and cold calls from tenants were
reduced by 20 percent.
Sharing the News
Given this success, ZRG’s operations
team is already working to replicate
this effort at other buildings within
the firm’s portfolio. Because of the
company’s overall commitment to
conserving energy and improving the
environment, ZRG also made it a
priority to share its experience at 311
South Wacker with other real estate
professionals. About 70 percent of the
office buildings in Chicago still use
the same pneumatic thermostats that
this building used to have, and they
can realize similar benefits in energy
savings and tenant comfort.
In February 2017, ZRG invited over
130 asset managers and building managers to 311 South Wacker so they could
see firsthand the ease of implementation and the benefits of this solution.
ZRG believes that Chicago can soon
become the smartest city in the U.S. for
energy retrofits of existing buildings. n
By Consolato Gattuso, senior vice president,
Zeller Realty Group
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