Simulation Study on Indoor Air Distribution and Indoor Humidity Distribution of Three Ventilation Patterns Using Computational Fluid Dynamics

Fangyuan Zhang,Yuji Ryu

doi:10.3390/su13073630

Abstract

Due to recent industrial developments and the COVID-19 pandemic, people are spending more time indoors. Consequently, many researchers have focused on the indoor environment, and indoor air quality is considered more important for human health. Improving indoor air quality depends on effective ventilation and reasonable air distribution. In an air-conditioned room, the form of airflow organization affects air quality, so air distribution is an important aspect of air-conditioning system design. In this study, we used Airpak software by Fluent to perform numerical calculations on the indoor humidity calculation model and study the effects of different ventilation methods on indoor temperature and humidity distribution. The Reynolds averaged Navier–Stokes equation and the RNG (Re-Normalisation Group) k-epsilon model were used to predict the airflow pattern in a room, the effects of ventilation on the dew rate, the effects of different ventilation methods, and the effect of indoor wall condensation. The results of the simulation showed that the ventilation mode significantly affected the distribution of condensation on the indoor wall surface.

Highlights

Nowadays, people spend most of their time (70–90%) indoors [1] and indoor air quality (IAQ) directly affects people’s lives and health
Comparing the condensation conditions under various ventilation modes, we found that when the amount of ventilation was the same but the ventilation mode was different, the condensation on each wall surface was very different
We established a mathematical model and used FLUENT software to simulate the effect of ventilation on indoor humidity and wall condensation

Summary

Introduction

People spend most of their time (70–90%) indoors [1] and indoor air quality (IAQ) directly affects people’s lives and health. Studying the influence of ventilation on the distribution of indoor wall condensation is valuable for the theoretical research of building moisture resistance and condensation prevention, as well as the design of ventilation engineering For compact spaces, such as offices, the impact of different air supply methods on the indoor thermal environment has been rarely studied. We used Airpak software to numerically simulate three common air supply methods in offices, namely, top air supply and return, side down air supply and side up air return, and side up air supply and side down air return, and we analyzed the results to select the optimal airflow organization for the air supply method, providing a theoretical basis for improving the thermal environment design of air-conditioned rooms. Compared to the room air age, the full air age can be seen as an absolute parameter and the full air age in different rooms can be compared

Methods

Post-Processing and Analysis of Simulation Results

Humidity Analysis

Mean Age of Air Analysis

Findings

Conclusions