Toyota Motor Engineering and Manufacturing North America: Fan System Upgrade

Background

Spurred by a successful pilot project at its facility in West Virginia, Toyota implemented a comprehensive heating, ventilation, and air conditioning (HVAC) system upgrade at its Georgetown, Kentucky plant. The company installed variable frequency drives (VFDs) to reduce air-flow during winter and non-production months to generate energy savings while maintaining indoor climate comfort and air quality. The project improves upon an aged, oversized system with constant speed airflow, and is expected to result in over $700,000 a year in energy savings, or about 2.5% of the plant’s total electric spend.

Several years ago, electricity rate increases at Toyota’s West Virginia plant led the company to experiment with installing VFDs on HVAC units to improve energy efficiency and keep energy costs low. HVAC costs represented 16% of total plant electrical costs and since the original system was designed for extreme weather conditions, it was oversized and not running at maximum efficiency. Installing VFDs on HVAC units facility-wide ultimately led to a 30-86% reduction in the HVAC system’s total energy use, depending on the time and season of year.

Employees from the West Virginia plant presented on their VFD project at a company facilities conference, as well as during a monthly internal webinar, and verified a simple payback of less than two years. Toyota’s corporate leadership took note of the results and established a 5-year strategy plan to replicate this project to the other Toyota plants; the Kentucky plant is now the fifth Toyota plant to pursue a similar HVAC VFD retrofit. The Toyota Kentucky plant, which started producing the first American-made Camry in 1988, is the company’s largest vehicle manufacturing plant in North America. The plant is a full vehicle production site involving plastics, stamping, powertrain, weld, paint, and assembly operations. In addition to the Camry, Toyota Kentucky manufactures the Camry Hybrid, Avalon, Avalon Hybrid and Venza, and four-cylinder and V-6 engines. Beginning late 2015, the plant will begin production of the first U.S.-assembled Lexus, adding 50,000 vehicles to its current annual capacity of 500,000 (the plant’s current engine production capacity is 600,000).

Solutions

Toyota installed VFDs on 211 motors throughout the Kentucky plant’s 164 HVAC units, to control fan motor speed, reduce airflow rate, and produce energy savings. With the VFDs in place, airflow can be reduced during non-production and non-summer months while still maintaining the same space temperature on the production floor. The project was completed in March 2015, with a year-long measurement and verification effort commencing in May 2015.

Existing equipment was modified and software was updated in-house as much of the plant’s equipment is no longer supported by the original equipment manufacturer and the plant’s Building Automation System dates back to 1987. Load reactors were also installed to protect the motor winding and limit the number of motor speed changes since most motors were old and not rated for VFD retrofits.

Toyota expects annual electricity savings of about 11,715,000 kWh attributable to this project. This equates to about a 2.6% reduction in the plant’s total electric consumption. The project’s implementation costs were around $1.25 million; about $460,000 were for the VFD purchases, and the remainder went toward installation costs. The project’s expected annual cost savings are $700,000 with a 1.8 year simple payback.

To minimize impact to production and keep costs low, all work—equipment installation, VFD mounting, conduit, terminating wiring at VFD, and building management system programming—was completed before the electrical tie-in at the control panel. The final control panel tie-in only lasted an hour. Building management system programming was completed using in-house labor resources, while all other aspects of project implementation relied on outside contractors. With the plant focusing on production, corporate provides the funding and resources to implement large energy projects at the plants.

Other Benefits

The Kentucky HVAC system retrofit contributes to Toyota’s 5-year energy plan. It is expected to help the plant achieve another ENERGY STAR certification in addition to the certification it received in 2014. It will also help Toyota make progress toward the 20% energy intensity reduction goal it set through the Department of Energy’s Better Plants Challenge.

Toyota worked through a number of technical challenges associated with this project that have resulted in several important lessons learned. For example, the project raised Toyota’s awareness of the required interrupt ratings and Short-Circuit Current Rating (SSCR) needed to safely and effectively operate VFDs; this awareness led the company to change its specifications. During some VFD installations, changes needed to be made to the electrical system to reduce the Prospective Short-Circuit Current to meet the VFD’s SSCR. As a result, Toyota now performs power studies before installing VFDs to identify if electrical system modifications are needed.

Toyota Motor Engineering and Manufacturing North America: Fan System Upgrade

ANNUAL ENERGY USE

ANNUAL ENERGY COST

ANNUAL WATER USE

ANNUAL WATER COST

ANNUAL PLANT ELECTRICITY USE

ANNUAL PLANT ELECTRICITY COST

IN BUILDING ENERGY USE

IN BUILDING ENERGY COST

ACROSS NETWORK USE

ACROSS NETWORK COST

ANNUAL EMISSIONS

HVAC USE

HVAC COST

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Toyota Motor Engineering and Manufacturing North America: Fan System Upgrade

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