Single Sided Ventilation: Room with a Heater

Single Sided Ventilation in a Room Considering a Heater — ANSYS Fluent CFD Simulation

Description

This project analyzes indoor airflow dynamics and thermal behavior within a heated room using natural single-sided ventilation in ANSYS Fluent. The setup features an aluminum heating radiator producing 23,469 W/m³ of thermal output as the primary heat source, while a side-mounted window serves as the natural ventilation outlet, operating at ambient atmospheric pressure with backflow temperatures matching interior conditions. The aim is to characterize the airflow patterns and thermal distribution that develop when a single opening ventilates a heated space — a configuration typical of everyday residential rooms. Within the HVAC Engineering: Beginner CFD Training Package, this project builds on the basic heated-room case by adding an opening, introducing natural ventilation coupled with an internal heat source.

Methodology

The three-dimensional room model was constructed in Design Modeler, with interior dimensions of 2.15 m × 2.16 m × 3.32 m and a rectangular heating unit positioned along the base of one sidewall to represent a typical residential heating configuration. The computational grid was developed in ANSYS Meshing using an unstructured topology of 987,087 cells, providing sufficient resolution to capture the flow and thermal boundary layers.

The simulation uses a pressure-based solver under steady-state conditions, combining fluid dynamics with thermal analysis and including gravitational effects (9.81 m/s²) to capture buoyancy. Turbulence is modeled with the realizable k-epsilon model using standard wall functions. The boundary conditions define the window as a pressure outlet at atmospheric conditions, the room surfaces as stationary walls with zero heat flux, and the radiator as a volumetric heat-generation source. Pressure–velocity coupling is handled with the SIMPLE algorithm, with high-order discretization schemes for improved accuracy and standard initialization at atmospheric conditions (101,325 Pa, 300 K).

Analysis

The analysis generates comprehensive flow and thermal field data, including pressure, temperature, and velocity distributions in both 2D and 3D. Velocity vector fields reveal the circulation patterns set up by the interaction between the radiator's buoyant plume and the ventilation flow through the window. Cross-sectional analysis is carried out on XY and YZ planes, with multiple YZ sections examined to fully characterize the three-dimensional nature of the heated room's airflow and thermal behavior. From these results you can assess how effectively the single-sided opening ventilates the space, how heat distributes through the room, and where warm or stagnant regions form.