A Modified T-Method Simulation for Multi-fan Duct Systems

Abstract

In this study, we introduce the Modified T-Method which can be applied to the prediction of the flow distribution in multi-fan duct systems. Introduction of individual flow routes enables the division of a complicated multi-fan ductwork into a set of simultaneous single-fan subsystems. The present method was tested on the single-fan duct system presented in the ASHRAE handbook. The test system consisted of several branches and a fan. Our results showed good agreement with those published. Also, we tried another approach, in which the symmetry of a two-fan duct system was investigated. Verification was accomplished successfully by the analysis of a two-fan duct system that yielded physical consistency. In order to evaluate the utility and capability of the title method, a bathroom ventilation system in a 20-storey residential building was selected as an example of an application. Under the typical design conditions, the air flow rate of each exhaust fan at the balance point was predicted