Analysis of Natural Ventilation Performance Gap between Design Stage and Actual Operation of Office Buildings

Xiuzhang Fu,Mingzhu Han,J Kurnitski,T Kalamees

doi:10.1051/e3sconf/202017209010

Abstract

Suitable natural ventilation in office buildings can not only reduce energy consumption of air conditioning, but also improve indoor air quality. In the architectural design stage, the effect of natural ventilation design is mainly simulated by CFD simulation software for indoor air speed, pressure, and age of air, etc.. However, during the actual building operation, the indoor natural ventilation effect will be affected by many factors, such as surrounding buildings, indoor layout, window position and open-close status, human behavior, etc., and the natural ventilation performance between design stage and actual operation is often different. In this paper, a typical office building was selected and FloVENT software was used to quantitatively analyse the influence of surrounding buildings, indoor layout, door/window opening conditions on indoor natural ventilation. Field measurement of indoor air flow rates in typical positions in office were carried out under different circumstances. In order to reduce the instantiate influence of outdoor wind speeds, a new index named Wind Speed Ratio(WSR) is put forward.Through comparative analysis of simulated data and measured data. the gap degree in natural ventilation performance between design stage and operation operation is discussed, and results show that the relative errors of the WSR, which could be considered to reflect the performance gap, are about 78.0%, 28.7% and 150% respectively, under corresponding condition settings of surrounding buildings, indoor layout, and door/window opening.

Highlights

People live in buildings 90% of their life, maintaining good indoor air quality is very important for people's health, comfort and high-quality life
Nomura and Hiyama [3] summarized the literatures on the field study of natural ventilation office buildings, the results show that the natural ventilation performance depends on the architectural design to a large extent
Based on the data of indoor temperature, airflow patterns, wind speed, energy consumption, internal heat gain, number of personnel obtained from 16 months of actual building field measurement, the parameters of the scaled building modelÿs experiments were used as inputs into a CFD simulation model to compare predicted and measured airflow patterns, temperatures and velocity distributions

Summary

Introduction

People live in buildings 90% of their life, maintaining good indoor air quality is very important for people's health, comfort and high-quality life. Natural ventilation is an important means to guarantee good indoor air quality, reduce indoor temperature in summer and control humid environment by introducing outdoor air. It has a great impact on building energy consumption. Scholars have found the natural ventilation performance gap between design stage and actual operation through field measurement and CFD numerical simulation. Based on the data of indoor temperature, airflow patterns, wind speed, energy consumption, internal heat gain, number of personnel obtained from 16 months of actual building field measurement, the parameters of the scaled building modelÿs experiments were used as inputs into a CFD simulation model to compare predicted and measured airflow patterns, temperatures and velocity distributions. Building simulation tools can theoretically provide main flow fields of buildings through simple formulas

Methods

Results

Discussion

Conclusion