Del Monte Foods Achieves Major Energy Savings with DOE Compressed‑Air Assessment

Del Monte Foods is one of America’s largest producers, distributors and marketers of premium‑quality food and pet products. In fiscal 2010 the company generated more than $3.7 billion in net sales, with brands such as Del Monte, S&W, Contadina, College Inn, Meow Mix, Kibbles ’n Bits, 9Lives, Milk‑Bone, Pup‑Peroni, Gravy Train, Nature’s Recipe and Canine Carry‑Outs. Del Monte’s products are found in 80 % of U.S. households and the company also produces private‑label lines.

The U.S. Department of Energy’s “Save Energy Now” program completed an Energy Savings Assessment (ESA) at Del Monte’s Plant No. 24 in Hanford, California. The assessment was led by Kyle Harris of Accurate Air Engineering Inc., a qualified DOE specialist in compressed‑air systems.

Hanford’s compressed‑air system relies on three 150‑horsepower rotary‑screw air compressors. Two units are water‑cooled, one is air‑cooled and has been retrofitted with a variable‑speed drive (VFD). Production runs for 12 weeks per year at full 24/7 operation during peak tomato harvest, and for nine months off‑peak at five days a week, 12‑24 hours a day. The plant typically runs all three compressors during peak periods and the VFD unit alone during off‑peak. Peak airflow exceeds 1,550 cfm; off‑peak drops below 450 cfm. The system consumes more than 980,000 kWh per year, accounting for over 5 % of total plant electricity.

ESA objectives

• Identify improvement opportunities for the compressed‑air supply, distribution and end‑uses.
• Train plant personnel to model the current system accurately.
• Project potential savings with DOE’s AIRMaster+ software.

Assessment approach

Data collection began over a week before the on‑site visit. Three air‑flow loggers and two pressure loggers were deployed, and historical data from a prior study was used to characterize off‑peak periods. The DOE expert and plant staff used LogTool V2 to process the data and import it into AIRMaster+, where a baseline compressed‑air profile was built.

During the assessment, a comprehensive survey of supply and demand was completed. Plant personnel, guided by the DOE specialist, developed a series of energy‑efficient measures, prioritized them, and presented the findings in a closeout meeting with key stakeholders.

Opportunity classification

• Near‑term – actions that can be implemented through operating practice changes, maintenance or low‑cost equipment purchases.
• Medium‑term – opportunities requiring new equipment or system modifications, supported by engineering and ROI analysis.
• Long‑term – initiatives that involve testing new technology under plant conditions and demonstrating economic viability.

Near‑term and medium‑term opportunities

• Reduce system pressure – The plant currently operates at 105 psig, while many end‑uses need less. Lowering the VFD set‑point to 95 psig and reducing its speed from 30 Hz to 27 Hz yielded an immediate 99,000 kWh (≈$9,400) annual savings, with a payback in a single month.
• Eliminate air leaks – Leaks account for more than 10 % of total demand. Observed 200 cfm of leaks at 95 psig, primarily on de‑palletizers. Tightening these leaks could save 73,000 kWh (≈$6,900) per year, with a payback of under four months.
• Remove open‑blowing (Line 4) – The plant uses compressed air to blow cans before coding. Replacing the quarter‑inch blow‑off fixture with a low‑pressure blower (3 psi) increases delivered energy by 28 % and eliminates 27 cfm of compressor‑room capacity. This change would save 6,800 kWh (≈$648) annually.
• Remove open‑blowing (pre‑coders) – Re‑routing coders to follow washers eliminates the need for pre‑blowing. Implementing this on all lines could yield 23,000 kWh (≈$2,300) per year, with a three‑month payback.
• Optimize compressor sequencing – The VFD unit’s minimum speed may be lowered to 616 rpm, allowing it to run within its turndown range during peak production. Reviewing control strategy and adding power and pressure monitoring could produce an additional 24,483 kWh (≈$2,400) in savings.

Management support

Richard Koch, the site lead and project engineer, fully backed the ESA. As a member of the Hanford plant’s Energy Team, he is committed to improving compressed‑air efficiency across all facilities.

For more details on DOE Energy Savings Assessments, visit the Industrial Technologies Program at DOE ITP.