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

Abstract

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 ).