Split System: Room HVAC

Split System: Room HVAC — ANSYS Fluent CFD Simulation

Description

This project uses ANSYS Fluent to simulate heated airflow distribution inside a room conditioned by a split air conditioner HVAC system, applying the fan module to model the airflow driven by the unit's two fans alongside natural buoyancy effects. A split system delivers conditioned air to a room through its indoor units, and the way that air circulates determines the comfort and temperature uniformity of the space. The simulation investigates how the heated air moves and distributes through an occupied space containing office equipment. Within the Fan: Beginner CFD Training Package, this project applies the fan module to a real split-system HVAC unit, building on the earlier fan-driven room cases toward a complete air-conditioning setup.

Methodology

The room geometry, including two split AC units and office apparatus, is built in SpaceClaim and meshed in ANSYS Meshing using an unstructured grid of 547,820 elements. The airflow from the units is modeled with the fan module, and turbulent flow is resolved using the realizable k-epsilon model, with the energy equation activated to capture the temperature distribution throughout the domain. The ideal-gas equation is applied to capture the air density variation with temperature, enabling the buoyancy effect to be modeled alongside the fan-driven forced convection.

Analysis

Streamline contours reveal the resulting flow pattern, driven by a combination of forced convection from the fans and free convection from buoyancy. Heated air rises due to its reduced density, gradually cools as it reaches the upper regions of the room, and falls back down — creating the characteristic circulating flow pattern observed in the results. From these results you can evaluate how effectively the split system distributes conditioned air through the room, how temperature and airflow develop around the office equipment, and where warmer or stagnant regions form. By the end of this project, you'll be able to set up a split-system HVAC simulation using the fan module, combine forced and natural convection with the ideal-gas model, and interpret the streamline and temperature fields that describe how conditioned air circulates through an occupied room.