The maintenance of Heating Ventilation and Air Conditioning (HVAC) systems is one of the fundamental activities in facilities management groups. HVAC systems are configured from basic types of components, such as dampers, fans, valves and coils, and there are usually multiple instances of the same type of components performing different functions in an HVAC system. For example, in relation to dampers, an HVAC system can contain an outside air damper, a discharge air damper, a return air damper, a mixed air damper, and multiple variable air volume dampers. It is also a similar case for other components such as valves, coils and fans. When HVAC mechanics perform maintenance activities, they usually need to check HVAC components with specific functions, and know information about such components, such as "where is the outside air damper?" The information related with different HVAC components can be represented and exchanged using Building Information Models (BIM). Among BIM data standards, IFC represents more information in relation to HVAC for Facilities Management (FM) purpose. However, the bottleneck of using IFC to provide information support for HVAC maintenance is that current IFC standard does not differentiate functions of HVAC components of the same type, and thus it is not possible to identify HVAC components with specific functions and retrieve their information from an IFC file directly. This study presents the need for an approach to deduce the functionalities of HVAC components from their existing topological information represented in IFC files. This approach, once formalized, can be used as a basis to automatically retrieve required information from IFC-based BIM for HVAC mechanics during maintenance tasks.