IFC-based performance data checking for ventilation system design

Abstract

ABSTRACT With the development of Building information modelling (BIM) tools, the non-geometric attributes of duct elements, such as size, flow rate, and pressure loss, can be exported directly. BIM has been used in numerous building projects. However, there is no clarity in checking the performance data in mechanical, electrical, and plumbing design using the Industry Foundation Classes (IFC) data. In this study, the IFC definitions for duct system, element, distribution port, and user-defined IFC-property set (Pset) according to the IFC2x3 specification are introduced. Based on the design criteria for ventilation system, three checking rules for friction loss, duct velocity, and the diffuser’s neck velocity are extracted. A sorting algorithm for duct elements in the ventilation system is proposed by searching the connections between duct elements and the related distribution ports. Furthermore, the critical path is determined by comparing path lengths from different diffusers to the AHU. Therefore, the IFC-based performance data checking for the duct design is proposed. A case study is also presented. The results show that the performance data of the duct elements in the critical path meet the design criteria, and the total pressure loss of the ventilation system is calculated.