This case deals with intelligent process cooling utilizing closed-loop
systems, point-of-use chillers and ambient air managed with efficient motors and
fans. Eliminating the traditional cooling tower with a closed-circuit fluid
cooler, the Frigel Ecodry System is designed to provide clean water at the right
temperature to process machines year round.
The case is a plastics manufacturer operating 22 injection molding machines.
Support equipment: 150 ton cooling tower for hydraulics with central chiller
utilized for HVAC and integrated to manufacturing floor to provide 60 tons of
mold cooling. The chiller is required to operate at 44°F and pump throughout the
The energy saving from Ecodry originated from a decentralized system saving on
energy from pumping, operating at proper chilled water temperatures (50 to
80°F), and supporting processes cooling temperature control versus managing
suboptimal temperatures from a central location with distributed thermal losses.
The ability to automatically provide ambient cooling utilizing the Ecodry in
lieu of chiller for cooling molds when dry bulb is below 71°F was an additional
savings factor. Table 2 shows the potential energy savings from this measure.
But what about the improvements obtained from cycle time improvements utilizing
smaller point-of-use chiller/temperature control systems providing higher flow
and pressure at the mold with 20 percent reduction in mold cooling times,
reduced mold changeovers with mold drain kits and improved product quality?
To measure the financial benefits from operations we used the Transformation
Planner financial benchmarking tool. Restating, the process is two steps.
1. Input the current manufacturing performance.
2. Model the expected or desired changes in percentages or dollars.
The model recalculates benefits in annual cash flow and balance sheet.
Calculating the improved state, we held the improvements in operational
performance to 5 percent although productivity improvements from cycle times
based on customer interviews achieved 20 percent and reduction in scrap and
rework by better control over mold temperatures would be reduced by 10 percent
or more over the current state .
The performance chart (Chart 2) shows the input/outputs from modeling with
manufacturing changes held to 5 percent in relative improvement or absolute
dollars with the target improvements ranging from 2-15 percentiles from this
The following charts show the computed savings in dollars accruing from a
broader range of savings not customarily computed based on annual revenue of
$243,000,000.This project moved from good to exceptional as these additional
savings were calculated.
Finally, annual water savings were 1,847,814 gallons (existing tower 1,981,076
minus upgrade at 137,262). Water Treatment pre-Ecodry equals $15,000 annually
and is reduced to $1,200 annually following installation. Total project savings
from water is $15,001 but raises a question about this resource: what are the
embedded electric costs with moving and treating all this water?
In conclusion, it is important to understand your process cooling system design
and the costs associated with operating it versus your plastic processing
requirements. Evaluate your process temperature and chiller loads. Understand
the cost of integrating chilled process water for plant manufacturing with
HVAC/comfort air. This can be a huge loss in energy and productivity.
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1) Extracted from Church, G. 2009: ACEEE Summer Study of Energy Efficiency
in Industry, “Energy Financial Project Analysis, What Have We Been Missing?”
2009 Summer Study Program in Industry, American Council for an Energy Efficient
Economy, Washington, DC, aceee.org.
2) A discussion about the relationship between calculating changes in
manufacturing performance and energy savings can be found at; La Palme, Glen, et
al: 2007, “Generating and Calculating Energy Intensity Savings from
Manufacturing Productivity Improvements”, 2007 ACEEE Summer Study of Energy
Efficiency in Industry, American Council for an 3) Energy Efficient Economy,
Washington, DC, aceee.org.
United States Environmental Protection Agency, Lean and Energy Toolkit, Revised
October 2007, EPA-100-K-07-003, www.epa.gov/lean.