Heater: Room HVAC

Heater Applied for a Room HVAC — ANSYS Fluent CFD Simulation

Description

This project models heat transfer from a wall-mounted radiator inside a room using ANSYS Fluent. The heater, attached to one sidewall, acts as a heat source with a constant heat flux of 1,886.792 W/m², warming the surrounding air and setting up circulation throughout the room. The study focuses on natural convection and buoyancy-driven flow, capturing how a single wall-mounted radiator distributes heat through an enclosed space. As the opening project of the HVAC Engineering: Beginner CFD Training Package, it introduces the most fundamental indoor scenario — buoyancy-driven airflow and heat distribution in a single heated room — laying the groundwork for the ventilation and heating cases that follow.

Methodology

The three-dimensional geometry is created in SpaceClaim, and meshing is performed in ANSYS Meshing with a structured grid totaling 87,865 elements. The heater is defined as a constant heat-flux source of 1,886.792 W/m². The sidewalls and ceiling are 0.2 m thick wood and exchange heat with the outdoors by convection, with an ambient temperature of 280 K and a heat-transfer coefficient of h = 10 W/m²·K. Gravity is included so that the buoyancy-driven motion of the warm air is captured. The energy model is enabled to resolve the conjugate heat transfer between the heater, the room walls, and the room air, capturing the buoyancy-induced circulation.

Analysis

Post-processing yields 2D and 3D contours of velocity, temperature, and pressure, along with pathlines and velocity vectors. The results show that the radiator elevates the room air temperature, with the strongest heating and velocity increases near the walls, especially in the vicinity of the heater. From these fields you can evaluate how effectively the radiator warms the space, observe the buoyancy-driven circulation pattern it establishes, and identify warmer and cooler regions within the room.