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.

Design Method of Vertical Ventilation with Wind Chimney on Roof Driven by Wind and Buoyancy

The calculation system for vertical ventilation with wind chimney on the roof driven by wind and buoyancy is presented and the necessary data is measured. The calculation system is based on the “pressure – airflow rate relationship (Pressure -Volume curve: P-V curve)” and the local velocity and static pressure at the point of chimney top. The P-V curves were measured by wind tunnel test for some typical shapes of wind chimney top. It is turned out that the effect of upper wind velocity can be eliminated by normalization of the pressure at chimney neck and airflow rate through the chimney.

Prediction of Heat Emission Effect at Small Single-sided Openings in Apartment Houses

In this study, we propose a method for forecasting heat emission effect in a small single-sided slit opening. In order to make a heat flux forecasting model, we carried out field measurement, wind tunnel experiment, and CFD analysis. In the field measurement, we measured heat flux and grasped the relationship of heat flux of the opening and airflow around the building surface. In the wind tunnel experiment, we measured airflow around the opening and grasped turbulence characteristics.

Energy Saving Potentials of Dedicated Outdoor Air System in High-rise Apartment Buildings

The main thrust of this paper is to investigate the optimized supply air condition and energy saving potentials of a dedicated outdoor air system (DOAS) applied to a high-rise apartment building. For a typical 132-m2 apartment unit, it was assumed that two different systems, namely, a centralized DOAS integrated with ceiling radiant cooling panel (CRCP) and a decentralized energy recovery ventilator (ERV) operated with packaged air conditioner, were installed.

Development of a heat pump system with the heat source network model using solar, ground and air heat source

In this research, a heat pump system with a heat source network is suggested which utilizes outdoor air heat, solar heat and ground heat as heat source for cooling, heating, hot water and refrigerating. This paper describes the summary of the suggested system and the results of the annual energy simulation. The heating and cooling loads, the electric consumption and the COP were calculated by TRNSYS 16 and evaluated in the cases of different local conditions and different system compositions.

Calculation of Dehumidification Coefficients for Numerical Simulation of Desiccant Wheel

In the previous study, a numerical method which simulates combined heat and moisture transfer process in solid desiccant materials was investigated. The calculation results successfully reproduced the cyclic process of the moisture adsorption and desorption. The validity of the numerical simulation method for the desiccant wheel was examined by the comparison between the experiment and the numerical simulation of the desiccant dehumidifier.

Measured Duct Leakage and Resulting Envelope Pressure Differences

As concern about IAQ has increased, forced-air distribution systems are being viewed as a potentially important factor in preventing the transport of indoor and outdoor pollutants. Duct leakage can be a confounding factor in attempts to use the forced-air system for this purpose. Leakage from outside into the return side of the system brings outdoor air directly into the distribution system through the leak. Supply leakage depressurizes the house which increases infiltration of outdoor air through the envelope.

A Study on Incomplete Ventilation in High-Rise Residential Buildings

Guideline for ventilation to improve indoor air quality in apartment housings in Korea was recently enacted and natural or mechanical ventilation system has become mandatory. Meanwhile, as the height of residential buildings goes up, the performance of ventilation system is influenced by stack effect especially in winter. This study is to review how stack effect influences ventilation system in high-rise residential buildings through simulations.

Case-Control study for the Association Between Indoor Environmental Factors and Children’s Health Problems in Japan – Part 2 Results of Measurements during Rainy Season and Winter

In order to clarify the association between indoor environmental factors and children’s health problems, indoor air quality was investigated during the winter and rainy seasons in Japan. The total of 209 houses was classified into case and control groups whether the child have allergy symptom or not. The number of the houses in case and control groups is 133 and 76, respectively. This survey included measurement of indoor temperature, humidity, the pollution of chemical compound and mite allergen (Der 1). These measurements were conducted in the living room and children’s room.

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