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Click here to return to this month's Article Index The Cutting Edge™ - September 2004Workplace ToolsInnovative Energy Efficient Industrial Ventilation Industrial Ventilation is a major part of energy consumption in the woodworking, metalworking, food processing, chemical, pharmaceutical, printing and other industries. This article describes an innovative on-demand industrial ventilation system. The main benefit from system installation is radical energy saving (67% average of all installed systems) in comparison with classical ventilation systems. Events of the recent years, increased prices of oil and gas, and the recent major blackout in the U.S. history which makes using energy-efficient equipment more important than ever before. The Ecogate® system is an excellent choice for a more energy-efficient environment. Validated ResultsSince its first commercial year 2000, the company has shipped over 13,000 gates, over 1,300 small & medium systems and over 65 Master Industrial Systems. A number of systems are already three years in uninterrupted service around the USA at major woodworking companies. The Ecogate® System has already gained industry acceptance. Among other environmental and energy-efficiency awards, Ecogate® won the prestigious Sequoia Award given by the Association of Woodworking® Furnishings Suppliers to organizations that demonstrate environmental innovation and leadership in energy conservation in 2001. The Ecogate® MASTER System was installed for evaluation and training purposes at North Carolina State University, Hodges Lab. The Principle Behind Ecogate® System Savings & DesignThrough extensive data collection, we have discovered that the typical woodworking manufacturer is actually producing sawdust only at 5% to 60% of its workstations at any given time. This percentage varies with first, second, third shift, type of factory (mill, cabinet maker) and by other factors.  Fig. 1: Typical activity of workstations at a major US woodworking producer during the first shift (best workstation 55% of shift time, worst 0%, average 23.5%). Note: red columns are representing comparison between workstations. As you see, only 23% of workstations are cutting material during the first shift, yet the dust collecting system is working all the time, with full power. The Ecogate® System solves this by creating computer controlled on-demand system. When a machine is turned on, a sensor signals the greenBOX® controller to open the appropriate gate. When the machine stops, the gate closes. The greenBOX® MASTER computer monitors the usage of all machines in the shop and, through the Power MASTER™ unit (with variable speed drive), it continually optimizes the amount of power supplied to the collector fan based on the software model of the system (duct system) and the software model of the fan. The System is programmed to keep a certain number of gates open at certain position, even if the machinery is not operating in order to maintain proper airflow through the system.  Fig. 4: Simplified block diagram of the Ecogate® System. Sensors and blast gates are connected to the greenBOX® MASTER unit. The greenBOX® MASTER unit regulates the speed (power) of the collector fan via a Power MASTER™ unit using a serial communication channel. A negative pressure sensor is connected to the greenBOX® MASTER. EMBED Visio.Drawing.6  Fig. 2: green line represents "real air-volume demand" of workstations in the factory; red line represents air-volume of a typically designed system minute by minute. Ecogate® system is designed to supply "demand" air-volume, with the result of average electricity savings of 67%. The next chart will explain how we can achieve high electricity savings (60-80%) - the so-called fan law.  Fig. 3: High energy savings are possible based on a law of physics called "the fan law": 50% reduction of air-flow (by automatically closing dampers on non-operating machinery) fan motor will need only 12.5% of consumption (an 87.5% savings). Thus, reducing air flow just 30% will yield a 66% savings.
To design an on-demand system by using automated gates is not that technically difficult, but the idea is to design a system, which maintains proper air-velocities. Dust collecting systems are transporting sawdust and if air-velocity in some part of ducting drops under a certain value, sawdust will settle in the ducting. Ecogate® solves this problem by using sophisticated software models, sensors, and proper duct system design, which is proprietary know-how covered by patent. Our customers can prove that we have solved the problem: sawdust settling has never happened to us on all running systems over the past three years. Consumption Evaluation Fig. 5: This chart shows the measurements at a furniture manufacturing facility in California, made by a third party (SC Edison): red line represents average consumption of dust collecting system without Ecogate® system (61 kW), green line average consumption with Ecogate® system (13 kW), a 79% reduction. We have similar results at all Ecogate® system installations. The average savings on all installed systems are 67% of electricity used for industrial ventilation. This information has been verified by one or more outside agencies. The typical electrical savings that most manufacturers see with the Ecogate® system have been in the range of 60% to 80%. Additional Benefits Created by Installing the ECOGATE® SystemIn addition to electricity savings, there are other benefits to the Ecogate® System. They include reduced noise, guaranteed air velocity at working drops, radically reduced startup current peak, corrected power factor (0.98 - 0.99), reduced wear & tear of fan motor and belt drive. Also, saved electricity will never have to have been produced in the first place, resulting in CO2 emissions reduction and waste reduction, which is called pollution offset. This fact enhances corporate image. For example, the three ECOGATE® MASTER systems installed at Autumn Milling factories (which won the 2002 ENERGY STAR Award) saved more than 200,000 kWh, which, in addition to significant money savings, will prevent about 248,000 pounds of CO2 emissions per year. Industrial Ventilation
Table 3: Summary of potential annual savings in USA by installation of Ecogate® systems. Ecogate® has measured thousands of air-velocities in drops and hundreds of air-velocities in main ducts. Average air-velocity from thousand of measurements in the drops is much lower than the recommended 4500-5000 FPM. Saw dust is known to cause cancer (as published in the Tenth Report on Carcinogens by the U.S. Department of Health and Human Services), and, according to the Industrial Ventilation Manual (published by American Conference of Governmental Industrial Hygienists), air-velocities below 4,000 FPM are not high enough to capture all the sawdust generated by workstations. Financing Energy Efficiency SystemsIncentive programs for installing energy efficient technology are available through government agencies and power utility companies in the U.S. and other countries. The incentive programs can cover up to 50% of the system cost. For example, companies that save energy with the ECOGATE® system can receive fixed-price incentives (for example, 8.0 cents/kWh saved) for measurable energy savings achieved in the territory of Southern California EDISON, the primary utility in Southern California. Other incentive programs are available from utilities in 20 states. The Ecogate® System represents an opportunity for industrial ventilation companies to offer an upgrade to all of their existing customers and enable maximum savings based upon Ecogate's® new technology. For more information, visit www.ecogate.com or e-mail to info@ecogate.com. Literature:1. The United States 2002 review, International Energy Agency, 9 Rue de la Federation, 75739 Paris, France Table of Contents
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