Fan Heater: HVAC System

Fan Heater for HVAC System — ANSYS Fluent CFD Simulation

Description

This project examines the performance of a fan heater and the resulting movement of heated air within a room, using ANSYS Fluent under steady-state, pressure-based solver conditions with gravity effects included. A fan heater combines two mechanisms: a heater warms the air, and a fan drives that heated air out into the room, so the flow is shaped by both forced convection (from the fan) and natural convection (from the buoyant warm air). The study captures how the heated air circulates and distributes through the space. Within the Fan: Beginner CFD Training Package, this project opens the fan-driven HVAC applications, combining a fan's airflow with heat transfer in a single room.

Methodology

The geometry was created in Design Modeler and meshed in ANSYS Meshing using an unstructured mesh, resulting in a total of 207,707 elements. Air circulating through the room passes over a heater positioned on one side, while the fan drives the heated air into the space. Turbulent flow is modeled with the RNG k-epsilon model, and the energy equation captures the temperature distribution throughout the domain. The ideal-gas equation is used to account for the variations in air density resulting from the temperature changes, so the buoyancy of the warm air is captured alongside the forced flow from the fan.

Analysis

The simulation yields contours of pressure, velocity, and temperature, among other parameters. The pressure contour shows a reduction in pressure near the heater, driven by the rise of the heated air, which moves upward through a combination of forced and natural convection. The streamline contour illustrates this flow pattern in more detail: as the air heats up, its density decreases and it rises toward the upper regions of the room; as it travels upward, it gradually loses heat, becomes denser, and eventually descends — establishing a recurring circulation pattern within the space. By the end of this project, you'll be able to set up a fan-heater simulation combining forced and natural convection, apply the ideal-gas model to capture buoyancy, and interpret the pressure, velocity, and temperature fields that describe how heated air circulates through a room.