Golden Temple Natural Foods - Northwest Food Processors ...

FIREFoodProcessing
RESOURCE EFFICIENCY THROUGH COLLABORATION
CASE STUDY
GOLDEN TEMPLE
O F O R E G O N
Compiled and edited by Jeff Goby, Oregon
Department of Energy intern January 2005
Expansion of natural
food plant offers a
golden opportunity
Executive summary
FoodProcessing
Industry
R esource
Efficiency
From its meager beginnings in the 1970s, the Golden Temple of Oregon, Inc.
has today become a multi-million dollar food processing business. Its
151,000 square-foot manufacturing facility in Eugene, Oregon produces Yogi
Tea ® , Wha Guru Chew ® nut bars, Sunshine Spa ® body care products, and
more for health food stores and grocery stores nationwide. It also produces
private-label, organic products for major national and specialty retailers.
As Golden Temple of Oregon, Inc. steadily expands, it also deliberates
about its use of available energy resources. When the firm added 26,000
square-foot cereal flake extrusion facility to its existing production space
in May 2003, it turned to its electricity supplier, Eugene Water and Electric
Board (EWEB) for assistance.
Benefits of VFD
•Reduced energy use and costs
•Reduced maintenance
•Reduced wear and tear
Adding 26,000 square feet for a cereal flake extrusion facility allowed Golden Temple of
Oregon, Inc. the opportunity to install energy-efficient equipment that reduces their base energy
use by 30 percent.
Page 1

CASE STUDY
GOLDEN TEMPLE
O F O R E G O N
EWEB suggested Golden Temple install variable frequency drive (VFD)
air compressors and direct expansion refrigerated air dryer in its new
production facility. The new systems serve the existing three production
lines as well as a fourth new line. The existing production lines were
previously served by five isolated compressors. The company now only
uses them for backup.
Benefits of the VFD air compression system installation include:
•Verified energy savings of 157,000 kWh per year (30 percent of base
energy use)
•Verified energy cost savings of $6,800 annually over the alternative
system consisting of a low-unload compressor and standard refrigerated
air dryer
• Less maintenance with only one compressor instead of five
•Reduced compressor and motor wear due to soft starting/stopping and
reduced revolutions
Background
The original mission of Golden Temple of Oregon, Inc. in the 1970s was to
create a company that served both the customer and the employee. Golden
Temple was a pioneer in socially-responsible businesses. It developed a work
environment that focused on the growth of the individual’s potential. Profits
from some of its products, such as its Peace Cereal line, go towards small
non-profit organizations working for world peace.
The mission served the business well. Today, Golden Temple of Oregon, Inc.
has a 151,000 square-foot manufacturing facility and employs 160 full-time
workers. The firm has three shifts working on state-of-the-art equipment.
The future looks bright for plant expansion.
In 2001, the Eugene Water & Electric Board (EWEB) offered to perform a
free lighting audit in Golden Temple’s manufacturing facility. The energy cost
savings from the recommended measures, along with the available tax
credit from the State of Oregon and incentive from EWEB, made the
project a “no brainer” according to Golden Temple Facilities Manager
Dennis Wigham.
Financial Overview
Installation cost:
$41,174
Oregon Business Energy Tax
Credit: $4,439
EWEB incentive:
$10,309
When the company decided to add a 26,000 square-foot cereal flake
extrusion facility to their existing production space in 2003, it again
turned to EWEB to help analyze the potential energy savings of new
equipment and obtain additional incentives.
EWEB suggested replacing the five existing and one proposed compressors
with VFD air-driven compressors and a direct expansion refrigerated air dryer.
Managers at Golden Temple wanted to use a Sullair compressor because
they had prior experience with that brand and felt it delivered excellent
value. EWEB’s free energy study of a 100 horsepower Sullair VFD
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CASE STUDY
GOLDEN TEMPLE
O F O R E G O N
Installation Cost
Air compressor: $32,938
Filters: $1,664
Direct expansion refrigerated
air dryer: $6,572
Total: $41,174
compressor and a Domnick Hunter CRD 500 direct expansion
refrigerated air dryer estimated that energy savings would pay back the
incremental cost of the VFD system in under three years. After
considering the simple payback, an estimated system life from 10 to 30
years, and other factors, the company’s management approved the project.
Chamco, Inc. (now Dickinson Equipment) delivered the compressor and
air dryer. Golden Temple staff designed and installed the system.
The installation went smoothly and did not interfer with production.
Actual energy savings are greater than anticipated. The VFD compressors
and dryer together reduce energy use by 157,000 kiloWatt hours (kWh)
per year, saving about $6,800 annually.
Features
• Sullair LS16V-100 VFD air compressor (100 hp, 480 V); microprocessor
controls allowing fast and accurate pressure control
•Domnick Hunter CRD 500 direct expansion refrigerated air dryer;
saves energy over a standard refrigerated air dryer by using less refrigerant
and smaller scroll-type compressor; the unit can be configured to
cycle under certain conditions.
• Filters to purify incoming air and outgoing compressed air
The new VFD air compressor serves air knives, venturis, and actuators on
the new production line and the three existing production lines. The new
efficient VFD technology replaced the old compressor system consisting of
five less efficient non-VFD compressors that were not linked together.
Golden Temple Facilities Manager Dennis Wigham (right) shows the plant’s new VFD air-driven
compressor to Oregon Department of Energy Program Analyst Bill Drumheller (left) and Senior
Analyst Mark Kendall.
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CASE STUDY
GOLDEN TEMPLE
O F O R E G O N
Many air compressors spend time throttling to vary output, and operate
at partial load. This practice wastes energy. A VFD-controlled (or variable
speed drive – VSD) compressor is more efficient for several reasons:
•Motor speed varies to meet load, thereby directly saving energy from
reduced motor power consumption (see graph)
• Since the mean pressure band on a VFD compressor is 2.9 pounds-persquare-inch
(psi) versus 7.3 psi on a conventional on-off system, the
mean system pressure on a VFD compressor is lower. The lower mean
pressure results in a 2 percent power savings.
Compressed air systems
Over the lifecycle of a compressed air system, the capital cost is about
12 percent, maintenance is 12 percent, and energy costs are 76 percent.
Thus, it always pays to have an energy efficient system. One national
study of air compression, applied to Pacific Northwest loads, found that
the compressed air users could reduce their energy use by 30 to 50
percent if thorough system improvements were made.
Compressed air is often used because it is clean, readily available, and
simple to use, but it is often the most expensive way to deliver power in a
plant. For this reason, users should consider more cost-effective forms of
power before considering compressed air. Inappropriate uses of
compressed air include any application that can be done more effectively
or more efficiently by another method. Some potentially inappropriate
uses of the compressed air and alternatives include:
Inappropriate Use
Open blowing
Personnel cooling
Parts cleaning
More efficient replacement
Fans, blowers, mixers (or use nozzles)
Fans
Brushes, blowers, vacuum pumps
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CASE STUDY
GOLDEN TEMPLE
O F O R E G O N
Resources
Project owner
Golden Temple of Oregon, Inc.
Dennis Wigham, Facilities Manager
www.goldentemple.com
(541) 461-2160
Equipment supplier
Dickinson Equipment Co.
(formerly Chamco Equip.)
(360) 695-4677
www.dickinsonequipment.com/
default.htm
VFD compressor
manufacturer
Sullair, Inc.
1-800-367-6737
Business Energy Tax Credit
Oregon Department of Energy
1-800-221-8035 (inside Oregon)
(503) 378-4040
www.energy.state.or.us
Electric utility
Eugene Water & Electric Board
(EWEB)
(541) 484-1125
www.eweb.org
Air dryers
Dryers remove water vapor from the air, which lowers its dew point — the
temperature that air can be cooled to before water vapor begins to condense.
Refrigerated air dryers remove moisture from the compressed air through a
mechanical refrigeration system to cool the compressed air and condense
water and lubricant vapor. They provide a pressure dew point of between
35˚F and 39˚F. Among refrigeration air dryers, there are two basic types:
direct expansion (non-cycling) and cycling dryers.
Cycling dryers cool the compressed air through an intermediate fluid. Two
heat exchangers, a compressed air chiller and refrigerant evaporator, fit inside
a tank that is filled with a thermal conducting fluid. The fluid is usually a
water and propylene glycol mixture. The refrigeration system removes heat
from the fluid which, in turn, removes heat from the compressed air. Since
the refrigeration system cools only the fluid, the refrigeration compressor is
“cycled off” once the fluid temperature is chilled to the required point. The
cycling feature conserves energy and minimizes dryer freeze-up. Cycling
dryers are best in systems with fluctuating air flow and inlet temperatures.
Direct expansion dryers cool the compressed air in an air-to-refrigerant heat
exchanger, called an evaporator. The warm compressed air flows into one
side of the evaporator while low pressure, liquid refrigerant is metered into
another side. The heat from the compressed air “boils” the refrigerant,
reducing the temperature of the compressed air. Operation of the
refrigeration compressor is continuous and therefore requires a combination
of control valves to regulate refrigerant flow as the heat load from the
compressed air changes. Since the unit operates continuously, a non-cycling
dryer should be selected for systems with a constant air flow. (The Domnick
Hunter CRD series of air dryers save energy by using less refrigerant and
using smaller scroll-type compressors. CRD models can be configured to
cycle under certain conditions.)
Recently, VFD control of refrigeration compressors has become available on
refrigerated air dryers. Most units can vary capacity from 50 to 100 percent.
However, some of the newest ones combine a cycling feature that allows the
unit to shut down completely below 50 percent capacity.
Transferability
Keep the following in mind when deciding to install a VFD compressor system:
•VFD compressors are most appropriate in systems in which the compressor
runs for long periods at partial load and energy prices are high.
•Energy savings will likely result in a one to three-year simple payback on
the incremental cost of a VFD compressor system.
•The simplest use of a VFD is for controlling a single compressor with
variable loads.
•With multiple compressors, the most efficient arrangement is to have
standard compressors turn on and off to satisfy the bulk of the load and
have one VFD controlled compressor satisfy the remaining variable load.
Page 5

FIRE
FoodProcessing Industry Resource Efficiency
Through collaboration,
the nation sustains the
most resource efficient
and globally competitive
food industry.
Northwest Food Processors
Association
California League of Food
Processors
California Energy Commission
Del Monte Foods
Idaho Energy Division
Lawrence Berkeley National
Laboratories
Northwest Energy Efficiency
Alliance
Oregon Department of Energy
U.S. Department of Energy
Washington State University
Energy Program
In 2005 the Northwest Food
Processors Association and
the California League of
Food Processors will deliver
additional expert information
and services to their members,
helping them make continuous
improvements in energy and
resource efficiency. The work
is funded under contract to
the National Association of
State Energy Officials, recipient
of a U.S. Department of
Energy grant.
www.nwfpa.org.
•VFD compressors should not be used to satisfy base loads. Because some
power is lost in the variable frequency control electronics, VFD compressors
at full load are less efficient than compressors with standard controls.
• It is possible to retrofit an existing compressor with a VFD, but inadequate
motor cooling and lubrication may result. Also, the price-per-kW
of compressor power will likely be higher when purchasing a separate
VFD since overall system price will be higher.
• Installing a VFD compressor is not the only way to reduce compressor
system energy use (and some of these measures should be done before
you install a VFD). Other measures include:
1. Eliminate unnecessary uses of compressed air.
2. Adjust end-use devices to reduce compressed air consumption.
3. Repair air leaks. Oone estimate found that a one-eighth inch leak in
an air compression system leads to about $2,000 in additional energy
costs per year.
4. Reduce system pressure. A rule-of-thumb is that overall compressor
energy consumption is reduced by 1 percent for every 2 psi decrease in
outlet pressure. With a fully loaded 100-hp compressor operating 8,000
hours per year, and electrical energy priced at $0.05/kWh, you would save
about $320 annually for each 2 psi reduction in outlet pressure.
5. Install controls for compressor sequencing (sequencing refers to the
order in which compressors are brought on and off line to satisfy
system air demand).
6. The coolest, cleanest, and lowest humidity air should be the source air
for the compressor to reduce energy requirements for drying and
increase filter life
7. Review the entire air compression system to eliminate flow restrictions
(such as undersized filters and regulators)
8. Install dedicated air compressors or booster compressors for isolated
loads that require high pressures
9. Install air storage or receiver tanks near large intermittent loads
Lessons Learned
If you decide to install a VFD compressor system, keep the following tips in mind:
•Before purchasing VFD compressor, discuss control requirements and
design the system
•Eliminate unnecessary uses of compressed air (such as open blowing and
parts cleaning)
•Reduce use of compressed air consumption by end-use devices
•Reduce system pressure
•Repair air leaks
•Eliminate flow restrictions (such as clogged filters or excessively restrictive
piping)
•Take advantage of all available financial incentives
Page 6