McKenney's, Inc. Energy Efficiency Case Study. For more visit http://mckenneys.com.

1. Case Study
McKenney’s impact on
hospital energy savings Project Team
žž Owner: Chief Engineer,
is felt immediately
major Atlanta, Georgia
medical center
žž Engineer/Contractor:
W
hen it was installed in 1975,
Beginning in the summer of 2009, a team McKenney’s Healthcare Group
the air handler unit (AHU)
of McKenney’s Energy Services engineers McKenney’s Energy Services
at a major Atlanta, Georgia,
began to measure the HVAC system energy
medical center was a state-of-the-art usage. For several months, McKenney’s The Challenge
technological breakthrough. It cycled fresh
gathered nearly 250,000 energy usage data žž Enhance energy efficiency of
outside air and provided heating and cooling
points from the main AHU and chiller plant vintage air handler unit (AHU)
for nearly 60 percent of the hospital. as part of its comprehensive analysis. This
žž Measure energy usage data
extended measurement and benchmark against
period gave an accurate proposed energy savings
“ hough the scope of the project
T picture of energy usage
was greater than imagined, it didn’t during a wide range of The Solution
outside air temperatures.
interfere with operations at all. In žž Conducted an energy audit
According to the hospital’s using McKenney’s compre­
fact, the hospital’s chief engineer hensive processes and cutting-
chief engineer, McKenney’s
noted the hospital staff didn’t even worked around-the-clock edge equipment
know McKenney’s was there.” to gather the necessary žž Compiled data and
data. The goal was to developed clear, concise
identify some cost-saving energy usage reports
A lot changes over 35-plus years. For the options, so everything from the supply air
žž Upgraded AHU chilled water
more than 400-bed facility, the massive temperature, coils and exhaust air tempera- coil control and reset condenser
piece of equipment had become more of ture was analyzed. water supply temp
a “dinosaur” than an innovator. There was
no way to efficiently modulate the cooling
Gathering from actual versus extrapolated žž Reduced the number of chillers
data, McKenney’s presented a current state and pumps required to meet
capacity. As a result, heating and cooling
energy usage report (along with backup data) chilled water flow requirements
was inefficient and expensive. Facing a
and a proposed future state energy usage
s
­ ignificant cost to replace the AHU, hospital The Results
report to hospital officials. It also offered
officials turned to McKenney’s for recom-
comprehensive recommendations to improve žž Positioned hospital to reduce
mendations on how to improve energy effi-
energy savings. central plant energy costs by
ciency by modifying the existing equipment.
16% for investment pay back
The findings revealed that the single plenum
McKenney’s was already familiar with in fewer than 18 months
design of the AHU severely limited facility-
many of the hospital’s mechanical systems.
wide temperature control. When one area žž Potential $98,000 annual
It had conducted design/assist and contract net savings (1.4 million kWh
of the hospital (e.g., operating rooms)
work for the hospital’s HVAC, plumbing, at $0.07/kWh)
service and building controls since 1994. continued on reverse
žž Reduced chilled water flow,
reheat flow and condensed water
For more information contact McKenney’s at 404-622-5000.
supply temperature requirements
info@mckenneys.com  www.mckenneys.com

2. Case Study
Central Energy Plant Power Usage – Original/Proposed/Actual
2000
1800
Central Energy Plant (CEP)
1600
Kilowatt (kW) Usage
1400
1200
1000
800
600
400
200
0
50-55 55-60 60-65 65-70 70-75 75-80 80-85 85-90 90-95
Outside Temperature Ranges
 Original State  Proposed State  Actual State
A follow-up energy usage report compiled by McKenney’s Energy Services team indicated even greater savings than the proposed future state savings.
wanted cooler temperatures, the antiquated facility could run a single chiller at higher findings and implement on-going HVAC
system lowered the temperature in other parts water temperatures and run the variable- system modifications to improve efficiency.
of the building as well. As a result, all of this speed pumps slower when necessary for The improvements are also enabling the
air had to be reheated, causing a massive big energy and cost savings. hospital to meet certain parameters for
waste of energy. healthcare facility guidelines. Now, the onsite
With the variable controls, the pumps can
engineering team is working with hospital
To alleviate this, McKenney’s recommended be run more efficiently using as little as
staff to establish “set points” throughout
that the hospital decrease chilled water flow 40 percent of the energy previously needed.
the facility, an initiative that should save the
requirements by adding new chilled water In addition, the control valves enabled the
hospital even more in cost and energy usage.
control valves. McKenney’s also recommended hospital to customize temperature settings
the addition of a variable-speed drive pump for specific areas throughout the facility. According to the chief engineer, McKenney’s
for the chilled water. exceeded expectations. Though the scope
The facility can now see how the sweeping
of the project was greater than imagined, it
The hospital’s chief engineer noted that once changes are improving efficiency via an
didn’t interfere with operations at all. In fact,
the recommendations were implemented energy management reporting system from
the chief engineer noted the hospital staff
they had an immediate impact. Previously, McKenney’s. The chief engineer monitors
didn’t even know McKenney’s was there.
the hospital was running two or three chillers usage and savings in real-time and meets
at once to handle the workload. Now, the with the McKenney’s team regularly to review
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