TO:
Regional Technical Forum
DRAFT 2/4/02
FROM: Ken Saulter, NWPPC1
RE:
Industrial Compressed Air System Efficiency Improvement as a C&RD Program
BPA Leadership in Compressed Air Analysis: BPA has long recognized the potential benefits
to the region due to compressed system air improvements. BPA provided funding for the
development of the AIRMaster 1.4 compressed air system and analysis software tool and
documented the benefits of its use by conducting seven industrial plant case studies. BPA also
funded AIRMaster 2.0, an enhanced version of the software designed in concert with a
compressed air system "technical experts" group. Later, the federal Department of Energy
provided the funding support to create AirMaster+. AirMaster+ is a nationally distributed
stand-alone compressed air system assessment tool, i.e. unlike AIRMaster 2.0; it doesn't require
Microsoft Excel for operation. AirMaster+ is suitable for compressed air system maintenance
planning, system energy use and annual cost benchmarking, efficiency measure energy savings
estimation, financial analysis, and for energy savings evaluation.2
The C&RD Incentive Program is largely a deemed savings program where an energy
efficiency measure receives a fixed incentive payment based on kWh savings resulting from
well-known end use measures. Where measures are less well known but can contribute to kWh
savings under generally well-understood conditions, the C&RD program makes a deemed
calculation option available to program participants. Finally, for relatively large and special
condition situations the deemed savings verification protocol approach is available. It is this
approach that is proposed for the identification of compressed air system electricity savings.
Research on Compressed Air Market: Based on their research on the compressed air energy
services market, the Northwest Energy Efficiency Alliance has found that the potential for
energy savings in operating compressed air systems is significant. In particular, NEEA states:
“The largest source of potential compressed air efficiency opportunities is in
improvements to existing systems. These opportunities differ significantly form site
to site, based on system characteristics. While some opportunities are simple and
inexpensive to identify (e.g., reduce pressure), many require a significant investment
in monitoring to identify the benefits and the appropriate strategy. Technical
opportunities include:
 Improved system operations and maintenance
 Compressor improvements
 Better compressor unit control
 Improved cooling and dehumidification systems
 Controls for sequencing compressors
 Leak reduction
1
Thanks to Gil McCoy, Washington State University, Olympia, WA for past discussions and comments on this draft
proposal and adding substantially to Table 1 He is a key developer of the AIRMaster software.
2
AIRMaster: Compressed Air System Audit and Analysis Software CASE STUDIES: Compressed Air System
Audits Using AIRMaster Version 1.4: BPA Contract #94B131124 TO#95AT64385, Oregon State University, 1995
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Design and mechanical improvements to distribution piping and system configuration
Improved end-use devices (e.g., nozzles)
Improved end-use applications of compressed air.”3
The AIRMaster+ software is designed to assess the energy and cost savings from energy
efficiency measures that are often recommended to improve the energy performance of
compressed air systems. These include:
1. Improve End Use Efficiency (Eliminate Inappropriate Compressed Air Uses)
2. Use Unloading Controls
3. Reduce System Pressure
4. Fix Leaks
5. Sequence or Stage Multiple Compressors
6. Reduce Run Time (Turn compressors off or use an automatic shutdown timer).
AIRMaster+ can be used to determine the energy and power demand savings for each measure
with interactive effects taken into account. Savings from a variety of retrofit actions can be
analyzed, such as installing dew point demand controls on dryers; installing zero-loss drains on
receiver tanks, or installing larger diameter distribution piping to reduce system pressure losses.
The software is also capable of analyzing complex measures such as installing a dedicated
compressor to meet a high-pressure load, installing a small compressor to meet light evening
loads, or incorporating an energy-efficient adjustable speed drive (ASD) trim compressor in the
engine room. The software can model any number of compressors, compressor types, or control
configurations.
Some AIRMaster+ Features:
1. Compressor performance and system airflow requirements are determined from on-site
electric power measurements. Data logger results are used to determine hourly electric
loads for any number of "day types". Generally, it is recommended that data loggers
track system power use over a one-to two-week period. One hour of high-resolution data
is also recommended---with readings taken at each compressor on 10 to 20-second
intervals.
2. Airflow performance can be directly measured with appropriate meters and entered
directly into the AirMaster+ 'Air Profiles' module. Alternatively, AIRMaster+ can
calculate system air requirements. The calculated airflows are based upon the availability
of hourly average kW, or hourly average volt and amperage readings.
3. Leak detection is normally done with an ultrasonic leak detector used during downtime
such as a weekend no-shift period, when production and noise levels are minimal. Leak
detection and elimination is recognized as an industry Best Practice that should be
undertaken part of a normal preventive maintenance program. Since leak identification
and repair is a constant and recurring activity with a short measure life, it should not be
eligible for C&RD incentives.
4. Pre-installation Measurement: Power meter and data logger information would be
entered into AirMaster+ to "baseline" the compressed air system annual energy use and
3
Compressed Air Efficiency: Northwest Energy Efficiency Alliance (NEEA) Market Research Report #00-58,
August 2000, p.iii, Executive Summary; NEEA, Portland, OR 97204
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operating cost. This would include overall plant production normalization of the system
load profile. This serves as the “before” energy use baseline.
5. Post-installation Measurement: After installation of the cost-effective energy efficiency
measures identified in the AirMaster+ assessment, data loggers are again used to gather at
least one weeks worth of hourly average airflow or power readings for each compressor.
This information is entered into AirMaster+ to determine post-installation facility annual
compressed air system energy use. Compressed air measure energy savings are
"verified" by taking the difference between the pre and post-installation estimates of
annual energy use.
An Important C&RD Issue: The Measure Life of Compressed Air System Changes:
The nature of existing CA system changes under the AIRMaster+ framework allows for both
labor-time O&M and capital equipment retrofit improvements to CA systems. In the former
case, labor time is used for leak detection and is likely to be the principal O&M or labor time
activity. In addition, normal maintenance on the compressor itself could include air filter
changes and equipment lubrication as appropriate. In the area of system management the main
activity involves, typically, improvements in run-time and system pressure and may involve the
installation of system loading and unloading controls with automation and storage capacity A
third area of activity is CA equipment selection in terms of matching compressor capacity or size
with the facility loads or the addition of ASD’s for rotary screw compressors, if indicated by the
AIRMaster+ analysis. Taken together these three kinds of system improvements can be used as a
framework for gathering expert opinion on appropriate assumptions to be used for the measure
life of CA system improvements. These categories amount to a three-part measure life table, an
initial version of which appears as Table 1.
The table summarizes the key efficiency measures that are often used as part of a CA system
improvement strategy. The effects of these retrofit changes can be modeled with the
AIRMaster+ software.
Furthermore, the differences in measure life can be accommodated within C&RD’s ProCost
model within which periodic short-term measure replacement can be included in the calculation
of the C&RD credit.
Using AIRMaster+ as a Program Evaluation Tool: As indicated above the capabilities of this
tool span both the technical and economic aspects of a CA system and provide a convenient
framework for collecting and analyzing site information with appropriate input data about the
site facility and about compressor technical performance from compressor manufacturers. These
features make this an attractive tool but, even more important is the parallel capability of preand-post installation performance measurement which provides a foundation for project and
program evaluation in an area judged to be essential from the perspective of calculating energy
savings potential.
Timeliness for C&RD: Bonneville Power has already served as a supporter of the initial Excelbased AIRMaster 1.4 and AIRMaster 2.0 and has sponsored the case studies performed and
published (cf. Footnote 1). The Northwest Energy Efficiency Alliance has conducted a market
assessment of the CA system energy efficiency services in the northwest region. Some of the
findings (circa 1998) relevant to this tool include:4
4
Ibid, pp. ii-iii.
3
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“There are significant opportunities to save energy in the compressed air marketplace
Most customers and contractors are not currently acting to optimize the efficiency of
compressed air systems.
Many contractors are considering becoming more active in compressed air system
efficiency, but will not move forward until they see changes in customer interest.
Most customers spend little time thinking about compressed air system efficiency,
and have limited faith in their existing contractors to address the issue.
A combination of recruitment, training, and demonstration could lead to significant
market transformation among large systems (over about 500 HP). In this case, market
transformation means sustainable, increased levels of system retrofit activity
independent of any subsidy.
However, large systems constitute only about half of the horsepower of compressed
air systems in the region. The potential for market transformation among smaller
systems is less certain and will take larger efforts.”5
Table 1. Measure Life of Compressed Air System Improvements
System Improvements:
O&M (Labor
Intensive)
Standard Maintenance Repair
Leaks, change filters, etc.
Load & Unload Controls
ASD’s for rotary screw
Matching compressor capacity
and load/install designated
compressor
Reduce System Pressure
Reduce Run Time
Every few
months
Sequence or Staging of
Multiple Compressors /Install
Automatic Sequencer
Eliminate Inappropriate
Uses/Install air knives,
engineered nozzles, blowers,
electric mixers
Desiccant Dryer Controls/Dew
Point Demand, Heat Recovery
Install Cycling Refrigerate
Dryers
System
Management
CA Equipment
Selection and
Controls
Several months+
Several years
Several years
Several years
Several months+
Several months+
Several months+
Several years
Several years
Several years
Several years
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Of the 300,000+ businesses in the Northwest, approximately 16, 000 are manufacturing establishments. Of these,
about 3,500 are classified as small-medium manufacturers with 20-499 employees. The vast majority of the
remaining manufacturing establishments (12,500) have less than 20 employees. The seven BPA Case Studies sited
(footnote 1) were small-medium manufacturers with an aggregate yearly consumption of 8 million kWh.
Compressed air energy use was 17.4% of plant total energy use. Total estimated compressed air system energy
savings for the seven audits was 4.05 million kWh or 49.2% of the compressor energy use.
4
Air Distribution System
Improvements/Increase pipe
diameter, install cross-connects
Several years
Expansion of the DOE Compressed Air Challenge Program: It is also noteworthy that the US
Department of Energy has supported a national Compressed Air Challenge program that will
soon launch a series of AirMaster+ training classes. The program includes certification of
technical persons in the use of AIRMaster+ as a CA system audit and analysis tool. Future
certified AirMaster+ users are expected to come from equipment distributors, ESCOs, large CA
end users, utility energy conservation program personnel and college and university staff.6
Proposed Compressed Air Protocol for the C&RD Program:
1) Recommend to BPA that Compressed Air Systems Energy Savings be included in the
C&RD program as a Site Specific Protocol for Compressed Air Systems.
This proposed CA System program would be a modified Site Specific Protocol No. 2, where the
later is intended for energy savings improvements in industrial processes.7 The protocol guidance
for compressed air efficiency improvements would include the recommendation that the
AIRMaster+ tool be the “required tool” for energy savings verification.
2) Recommend to BPA that energy savings projects that use AIRMaster+ as a Compressed
Air System analysis tool be eligible as an RD&D project under the Guidelines set forth by
the C&RD Implementation Manual (Sections 4.8 and 4.9).
In addition to a formal proposal to be submitted to RTF the underlying project must demonstrate
a high probability of widespread kWh savings and the demonstration of the AIRMaster+ tool for
Compressed Air energy savings verification analysis. The following objectives of Compressed
Air RD&D projects would be of interest as part of appropriate RD&D projects:
a) Demonstrate the utility of AIRMaster+ as a pre-and post-installation evaluation tool as
well as a system audit and analysis tool. Determine the role of auditor training in reliable
tool findings and assess the benefits of Compressed Air Challenge training and
certification.
b) Incorporate Compressed Air System measure life analysis as part of the project including
expanding the discussion of measure life estimation. One approach here would be to poll
known CA experts on an appropriate measure life for the EE measures most often
recommended as compressed air system improvements.
c) To reduce outcome uncertainty and lower cost risk, conduct studies of post-installation
results and compare actual results versus projected results and identify the factors that led
to large variances in projected results.
6
7
For information on this program visit its website at www.oit.doe.gov/bestpractices/software/airmaster_cert/shtml
See Appendix P, Energy Savings Verification Protocols, C&RD Implementation Manual, pp.21P-22P, Oct 1, 2001.
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3) Recommend that, within BPA and RTF, that discussion and analysis of how to achieve
verifiable and sustainable CA System efficiency improvements be encouraged.8
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c:\documents and settings\saulter\my documents\air compressors\compressed air system as c&rd 2-5-02.doc (Ken Saulter)
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For example: a) become familiar with Washington State University Energy Program regarding AIRMaster+
technical support and the Compressed Air Challenge program in the region. b) identify regional Compressed Air
Challenge members and those that are trained and certified as AIRMaster+ Specialists. Discuss training and
certification issues with Compressed Air Challenge technical support staff c) determine role of marketing CA
improvement programs and expanding the number of trained compressor air system specialists.
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