Implementation of measurement and quality frameworks in the French regulation for achieving airtight envelopes

It is foreseen that the 2012 version of the French regulation will include a minimum requirement for the envelope airtightness of residential buildings, with two options to justify its treatment: a) measurement at commissioning or b) adoption of an approved quality management approach. This paper describes the qualification process for authorizing technicians to conduct airtightness measurement when the result is to be used in the EP-calculation method. It also discusses the requirements set for approved quality management approaches.

Influence of natural ventilation usage on cooling energy consumption and cooling capacity of an air conditioner

In Japan, natural ventilation through large openings has been used for cooling in summer and medium season. However, air conditioner has become popular recently, because it is hot and humid in summer in most parts of Japan. It causes cooling energy consumption to rise continuously. Nowadays, as global warming has become a serious problem, natural ventilation has been considered as a key method for cooling energy conservation. However, there is insufficient knowledge of natural ventilation effectiveness on cooling energy conservation quantitatively.

The influence of stochastic modeling of window actions on simulated summer comfort in office buildings

In this study, an attempt is made to define building design variables for a medium-sized office building with individual office cells in order to provide sufficient summer comfort without active cooling in a moderate climate.
Firstly, an approach to take realistic window-opening behavior into account is proposed based on observational data in literature. A stochastic model is defined for an active and a passive user, representing the variability between individuals.

Fungal Growth Prediction on Building Materials by Reaction-Diffusion Model Coupled with Heat and Moisture transfer

A mathematical model that reproduces fungal proliferation and morphological colony formation was developed on the basis of a reaction diffusion modeling approach. In this modeling, fungus was separated into two states, active and inactive, and it was assumed that active fungus moves by diffusion and reaction while generating and producing inactive fungus. The effects of temperature and humidity on fungal growth were explicitly incorporated in the reaction term of nutrient consumption/generation of active fungus in this governing equation.

Modularizing and Validating CFD Parts of Four-way Cassette Type Outlets

In this paper, we created the CFD parts of four-way cassette type outlets for predicting easily the thermal environment of an office with packaged unit air-conditioning systems. At first we measured detail distributions of wind velocity around the cassette type outlets in two cases of angles of flap in an experiment room with particle image velocimetry (PIV).

Solar Greenhouse and natural ventilation

The paper presents a study on the thermal behavior of a solar greenhouse set against one apartment of a residential eco-sustainable building in a temperate climate. Particular attention was given to the analysis of the contribution of solar radiation in winter heating in relation to natural ventilation. This study makes use of a transient energy simulation system named ESP-r (Environmentals System Performance - research).

Modelling wind driven airflow rate with CFD and verification of approximation formulas based on wind pressure coefficients

An isothermal CFD study was made of a building perpendicular to the wind direction. The building was modelled with a closed façade, and consecutively with one and multiple openings. The sensitivity was investigated for different turbulence models, meshes and near wall treatments, both in 2D and 3D. A large sensitivity was found to the modelling options with regard to the predicted wind pressure coefficients (Cp) distribution, but less with regard to the predicted flow rate through the openings.

Development of Zonal Model for Predicting Temperature Distribution inside an Office Room with Hybrid Air-conditioning System

Recently, the hybrid air-conditioning system that used natural ventilation together with a mechanical air-conditioning was proposed. Hybrid air conditioning system is expected to be saving energy and maintain keep indoor thermal environment comfort.

Effect of Intermittent Operation of Ventilation System on Indoor Air Quality in Apartments

This study analyzed the effect of intermittent operation of ventilation system on changes of indoor air pollutants' levels through field measurements. The changes of indoor air pollutants' levels, such as, CO2, PM10, TVOCs, and HCHO were monitored during 24 hours at each ventilation condition. One group was the operation time: 2 hours, 8hours, and 24 hours. The other group was the changes of start time of ventilation, before noon, after noon, and night, while the ventilation was operated only two hours.

Influence of the Configuration of Consecutive Street Canyons and Atmospheric Stability

This research, based on Computational Fluid Dynamics (CFD) analysis, focuses on the wind characteristics and the ventilation performance in the consecutive street canyons produced by various building complex configurations. In this research, the buildings in the street canyon space were distributed in either staggered or normal arrangements and, in consideration of the varying distribution and height of different buildings, high-rise buildings, middle-rise buildings and low-rise buildings were all included.