The Kaiser Aluminum plant in Sherman, Texas, improved its annual furnace energy intensity by 11.1% after implementing recommendations from the Save Energy Now assessment. 

Energy Assessment Helps Kaiser Aluminum Save Energy 

and Improve Productivity 

DOE Software Adopted as Standard for Analyzing Plant Process Heating Systems Company-Wide 

Industrial Technologies Program Case Study

Key Findings

•	Opportunities for energy efficiency do not require

large capital expenditures to achieve significant

energy savings.

•	The DOE Process Heating Assessment and Survey

Tool (PHAST) software was important to the success

of the assessment at the Kaiser Aluminum plant in

Sherman, Texas, and is now used to analyze process

heating systems corporate-wide.

•	Adjusting burner controls and repairing a furnace

door sill and jamb resulted in significant energy

	 savings.

•	Energy efficiency measures can lead to improved

production and other benefits such as reduced maintenance and lower emissions.

Applications

Process heating accounts for a large share of the

energy used by the aluminum fabrication industry.

Measures that improve furnace efficiency and reduce

heat loss in the process heating applications of secondary aluminum plants can yield significant energy

savings and better productivity.

Summary

A U.S. Department of Energy-sponsored (DOE) Save

Energy Now assessment was performed at Kaiser

Aluminum’s aluminum extrusion plant in Sherman,

Texas, in 2006. Using DOE’s Process Heating Assessment and Survey Tool (PHAST) software, DOE Energy

Expert Richard Bennett of the Janus Technology Group

worked with plant employees to analyze the plant’s

process heating systems. The assessment identified

opportunities that would result in significant energy

savings in some of the melting furnaces. By implementing these opportunities, plant personnel were

able to achieve significant natural gas savings.

Employees at the Sherman plant wasted no time

moving forward with the opportunities that had the

greatest energy savings potential. First, they adjusted

burner controls on one of the main reverberatory melting furnaces to lower excess oxygen levels. They also

made some repairs to the furnace’s door sill and jamb

to prevent cold air from seeping into it. By implementing these measures the plant achieved annual energy

savings of approximately 45,000 MMBtu and improved

the furnace’s energy intensity by 11.1% between

2006 and 2007. With project costs of approximately

$28,000 and energy cost savings of $360,000, the

simple payback was under 1 month. In addition, Kaiser

Aluminum adopted the PHAST as the corporate tool

for assessing process heating applications. To date,

the company has used the tool to evaluate furnace

efficiency at five other plants with casting operations.

Saved approximately

$360,000 in annual 

natural gas costs 

Achieved annual energy

savings of nearly 

45,000 MMBtu

Improved furnace energy

intensity by 11.1% annually

Achieved a simple payback 

of less than 1 month

Improved productivity

Benefits
Company and Plant Background

Founded in 1946, Kaiser Aluminum is a leading 

producer of fabricated aluminum products for 

aerospace and high-strength, general engineering automotive and custom industrial applications. The company employs 2,000 people in 11 

fabrication plants in North America and typically 

produces and ships more than 500 million pounds 

of aluminum products annually. In 2006, Kaiser’s 

revenues were more than $1.3 billion.

The Sherman, Texas, facility is a fully-integrated 

aluminum extrusion plant manufacturing quality 

fabricated aluminum products including sheet, 

plate, billets, redraw rods, extrusions, forgings, 

and tube products. The plant has two main operations: the cast house, where aluminum scrap and 

ingot are remelted and cast into direct chill billets; 

and the extrusion plant, where a portion of the 

cast house production is converted into aluminum 

extrusions. 

The cast house has two natural gas-fired reverberatory melting furnaces that feed one gas-fired 

holding furnace, from which the billets are cast, 

and one homogenizing furnace where the billets are heated to produce a more uniform alloy 

structure. In the extrusion plant, three extrusion 

press lines are each served by a natural gas-fired 

tunnel-type billet heating furnace, along with three 

gas-fired aging ovens to heat-treat the finished extrusions. Natural gas consumption at the Sherman 

plant was more than 452,000 MMBtu in 2005. 

Assessment Overview

The assessment at the Sherman plant was conducted by a DOE Energy Expert who is a qualified 

specialist on the use of PHAST, a software tool 

developed by DOE for analyzing process heating applications. The Energy Expert formed an 

assessment team with several plant employees to 

analyze the plant’s furnaces using the PHAST. The 

team combined field test data with corporate energy use and production records on three representative furnaces to determine whether any improvements to equipment or operating conditions would 

improve energy efficiency. 

2

Kaiser Aluminum’s Sherman plant operates three extrusion press lines like the 

one pictured above, which convert aluminum scrap and ingot into aluminum 

extrusions. 

Project Drivers

At Kaiser Aluminum, energy efficiency is a high priority in keeping with the company’s emphasis on Lean Manufacturing and Six

Sigma methodologies. The Save Energy Now assessment revealed

ways that would enable the plant to not only save energy, but also

to improve production. The possibility of productivity improvements,

coupled with significant energy savings, provided a high degree of

motivation for the plant’s employees to implement the most feasible

recommendations from the assessment. Because these energy

efficiency opportunities were cost-effective, the plant was able to

execute them quickly and easily.
Near-term opportunities

• Burner Tuning—The assessment identified excess 

oxygen levels of 5% in the reverberatory furnace. 

This condition occurred during the furnace’s high 

fire period, which lasted for slightly more than 50% 

of every melt cycle. By adjusting the air-to-gas ratio 

in the burner system from 5% to 2%, the assessment 

showed the plant could lower the average energy use 

per hour in the high-fire period by approximately 

16%. This was estimated to yield natural gas savings 

of more than 18,000 MMBtu and approximately 

$218,000 per year. 

• Reduce Furnace Heat Losses—Upon close inspection of the same reverberatory furnace, the assessment team realized that there was some damage to 

the door and surrounding sill and jamb. This damage 

allowed cold air to leak into the furnace during the 

period of each melting cycle when the burners were 

off, causing the furnace to cool. During the next 

melting cycle, the burners needed to operate for a 

longer period of time to bring the furnace up to the 

required temperature. The assessment recommended 

repairing the door sill and jambs to improve the seal 

and keep cool air from infiltrating the furnace. It 

calculated the plant would save more than 19,000 

MMBtu and achieve energy cost savings of more 

than $225,000 annually from implementing this 

measure. 

Medium-term opportunity

• Optimize Furnace Air Flow—Analysis of the 

homogenizing furnace found that it had poor air flow 

uniformity. Because of this condition, some sections 

of the furnace took longer to reach the necessary 

temperature. This increased the holding time and 

resulted in excess energy use and longer production 

cycles. The assessment projected correcting the air 

flow and temperature would yield annual energy 

savings of 1,621 MMBtu and $19,000 per year. More 

significantly, the assessment also calculated this 

opportunity could reduce cycle time by up to 27%, 

thereby increasing the number of loads that could 

pass through the furnace. 

If implemented, the total annual energy cost savings from these measures was estimated at more than 

$462,000

3

Assessment Recommendations

After analyzing the data using the PHAST software, 

the assessment team came up with three energy savings opportunities. They classified these projects based 

on expected energy savings, technical and economic 

feasibility, and payback periods of near- and mediumterm. 

“The Save Energy Now assessment was a tremendous asset in

helping us identify energy savings opportunities. The process

provided insight into new areas we had not previously considered and validated merits of potential projects we previously

identified. We found the experience quite helpful and have

already begun to incorporate ideas from the assessment.”

—David Conrow, Vice President,

Kaiser Aluminum Production System

Kaiser Aluminum’s Sherman plant makes custom parts for end-use 

applications in the transportation market, including trailer components and 

truck parts.
Results

Eager to save energy, employees at the Sherman 

plant tuned the burner controls to adjust the excess 

oxygen levels in the reverberatory furnace. This 

brought the excess oxygen levels down to 2% 

and improved the furnace’s thermal efficiency. 

Next, they fixed the furnace’s door sill and jamb 

and improved the seal. They also used better 

design criteria to prevent the seal from cracking. 

As a result, the burners can bring the furnace to 

its required temperature in a shorter period of 

time. The company determined that correcting the 

airflow uniformity problems in the homogenizing 

furnace would require significant capital expenditures. Therefore, the project was not implemented, 

although it remains under serious consideration.

Despite changes to the product mix since the 

assessment that require additional heat treatment, 

the implemented measures:

• Yielded annual energy savings of approximately 

45,000 MMBtu, representing nearly 33% of the 

furnace’s and 10% of the plant’s 2005 natural 

gas consumption, respectively 

• Improved the furnace’s energy intensity 

by 11.1%

• Made the processes served by the reverberatory 

furnace less sensitive to volume fluctuations, 

which improved the consistency of the energy 

consumption per pound of product and reduced 

some production bottlenecks that were caused 

by volume fluctuations. 

• Cost the company $28,000 and resulted in 

energy cost savings of $360,000, yielding a 

simple payback of less than 1 month.

Kaiser Aluminum Utilizes DOE PHAST 

Software to Analyze Process Heating 

Systems Company-Wide

• Based on the success of the assessment and the 

quality of the DOE training on process heating 

system analysis, Kaiser Aluminum adopted the 

assessment methodology and the PHAST software as their main diagnostic tool for process 

heating applications. 

• The corporate energy manager visited each of 

the company’s North American production facilities to introduce the tool and share the results 

from the Sherman plant.

• Five other Kaiser Aluminum plants with casting 

operations have used the PHAST to evaluate the 

efficiency of their respective process heating applications. As a result, significant opportunities 

have been identified and are going through the 

capital procurement process. 

• The company uses the software tool as a reference instrument to normalize data between 

furnaces in different facilities.

With implementation costs of $28,000 and cost 

savings of $360,000, the simple payback was less 

than 1 month. 

Lessons Learned

Often, industrial process heating applications can 

achieve significant energy savings by implementing measures that do not require large capital 

expenditures. At Kaiser Aluminum’s plant in 

Sherman, Texas, misadjusted burner controls, 

some minor furnace door damage, and improper 

airflow characteristics reduced the efficiency of 

one of the plant’s furnaces, which led to excess 

energy consumption and slower production. A 

Save Energy Now assessment performed using 

DOE’s PHAST software was instrumental in 

bringing these issues to light and calculating the 

energy savings and production benefits that would 

result by taking corrective action. By implementing some of the assessment’s central recommendations, the plant was able reduce energy usage and 

improve productivity. 

In addition to the PHAST, other DOE software 

tools can similarly be used to analyze industrial 

systems and processes and generate significant 

energy savings opportunities. These include: 

AIRMaster+, the Fan System Assessment Tool 

(FSAT), MotorMaster+, the Steam System Assessment Tool (SSAT), the Pumping System Assessment Tool (PSAT), and 3E Plus®. 

About Save Energy Now

Through Save Energy Now, DOE’s Industrial Technologies Program (ITP) helps industrial plants operate more

efficiently and profitably by identifying ways to reduce

energy use in key industrial process systems.

Visit www.eere.energy.gov/industry/saveenergynow 

for more information.

A Strong Energy Portfolio for a Strong America

Energy efficiency and clean, renewable energy will mean a stronger economy, a cleaner environment, and greater energy independence

for America. Working with a wide array of state, community, industry, and university partners, the U.S. Department of Energy’s Office of

Energy Efficiency and Renewable Energy invests in a diverse portfolio of energy technologies.

For more information, contact the EERE Information Center, 1-877-EERE-INF (1-877-337-3463), www.eere.energy.gov

And visit the DOE Industrial Technologies Program home page: www. eere.energy.gov/industry

DOE/GO-102008-2561

July 2008 4

The Sherman plant manufactures custom industrial 

electronic parts and water 

heater components.