Use of Statistical Approach to Design an Optimal Duct System for On-demand Industrial Exhaust Ventilation

This paper elaborates on how to use statistics to calculate optimal parameters (including duct diameters) of energy-efficient industrial ventilation systems. Based on the fan-law, on-demand ventilation can save up to 80% of electricity compared to classical systems. For the purposes of this paper, we consider a classical exhaust ventilation system one that uses constant fan RPM and air velocity in the ducts. There are multiple design and operational challenges to successfully implementing an on-demand system. Several of these challenges and their solutions are described in this paper. The basic idea behind on-demand ventilation is to close ventilation outlets at workstations that are not producing dust (or fumes or mist) and adjust the fan speed accordingly. It is easy to implement such a system if there is no requirement for minimum transport velocities in the ducting, as is the case in fume collection systems (such as welding shops). The task becomes challenging when particulate matter has to be transported in the duct system because minimum air velocities have to be maintained in every part of the ducting in order to prevent settling (which presents a fire and explosion hazard )

Innovative Energy Efficient Industrial Ventilation

This paper was written to describe an innovative “on-demand” industrial ventilation system for woodworking, metalworking, food processing, pharmaceutical, chemical, and other industries. Having analyzed existing industrial ventilation in 130 factories, we found striking dichotomy between the classical “static” design of ventilation systems and constantly changing workflow and business demands. Using data from real factories, we are able to prove that classical industrial ventilation design consumes 70 % more energy than necessary. Total potential electricity saving achieved by using on-demand systems instead of classically designed industrial ventilation in the U.S. could be 26 billion kWh. At the average electricity cost of 7 cents per kWh, this would represent $1.875 billion. Eighty such systems are already installed in the USA and European Union