BIM (Building Information Modelling) has been revolutionising construction for several years. For the HVAC commissioning engineer, the digital model is a valuable source of information that changes the way site work is prepared and carried out.
What is BIM in HVAC?
HVAC BIM is the 3D modelling of all heating, ventilation and air conditioning systems in a shared digital model. Every object (AHU, duct, valve, diffuser) carries technical data: flow rate, output, diameter, manufacturer reference. The standard exchange format is IFC (Industry Foundation Classes).
What BIM brings to the commissioning engineer
- • Site preparation: view the systems in 3D before arriving on site and identify measurement points.
- • Access to technical data: design flow rates, outputs and pump curves directly in the model.
- • Clash detection: clashes between packages (HVAC vs structure, HVAC vs plumbing) are picked up early.
- • Digital O&M file: the as-built documentation (DOE) is integrated into the model and accessible from a tablet on site.
- • Digital twin: in operation, a BIM model connected to the BMS enables real-time monitoring.
Levels of detail (LOD)
- • LOD 200: approximate geometry, suitable for preliminary design.
- • LOD 300: precise geometry with actual dimensions — the standard level for commissioning.
- • LOD 400: fabrication level, with installation details.
- • LOD 500: as-built, the model as constructed, the basis of the digital twin.
FIELD TIP
Even if you do not model yourself, learn to navigate an IFC model with a free viewer (BIMvision, Solibri Anywhere). It saves a considerable amount of time when preparing site work.