English

Cross-ventilation is regarded to be beneficial control method to obtain thermal comfort in a hot summer without using mechanical devices. Since it is complicated flow phenomenon, details of flow characteristics have not been sufficiently known. The final goal of this work is to establish a new prediction method of flow rate based on energy balance within the stream tube passing through or around the building. To validate numerical results obtained by CFD, they need to be compared with experimental results.

Korean government established a target to reduce greenhouse gas (“GHG”) emissions to 30% by 2020 to cope with the United Nations Framework Convention on Climate Change (UNFCCC) and secure its national competitiveness, and prepared a roadmap to develop this project. Especially, the government set up the objective of Zero Energy Consumption for the newly constructed multi-family housings by 2025 to reduce CO2 in the building sector.

Reduction of infiltration in the Equinox House, a residence under construction in Urbana Illinois, has been characterized through a series of blower tests as different joints and seams in the building were sealed. Equinox House is constructed with 30 cm thick SIPs (Structural Insulation Panels) wall and roof panels consisting of a Styrofoam core and oriented strand board sheathing on interior and exterior surfaces. Blower door tests were performed as each type of seam in the house was sealed.

The objective of this paper is to present a new method for estimating effective flow areas not only in the external wall of a house but also in the internal walls between rooms using only one type of tracer gas. The discharge coefficient of each wall and the pressure in each room—which are unknown variables—are determined using nonlinear simultaneous equations, which consist of balance equations for the air mass and tracer-gas concentration in the rooms. To verify the validity of this method, we performed a numerical experiment.

Museum showcases represent a peculiar confined space were ventilation and indoor climate conditions play an important role. Conservation of the works of arts, in fact, requires a control of the environmental parameters, with a tolerance usually far tighter than that required for assuring the comfort of people.

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.

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.

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.

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.

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).