This paper presents the benefit of natural ventilation of a roof cavity to reduce summer thermal loads ofa factory and, therefore, the cooling load due to air-conditioning systems with respect to various climatezones in Japan. A simulation program was developed to analyze the impact of cavity ventilation on theoperative temperatures of the occupied zones in a factory. Three climate zones in Japan: cold region(Sapporo), temperate hot-humid region (Tokyo), and subtropical region (Naha) were selected forcomparison. In an air-conditioning mode, two calculations of cooling loads were made.

The goal of this work is to investigate the ability of three eddy viscosity turbulent models, the standardk-?, the RNG k-? and the k-?, in predicting the three-dimensional airflow in a room under forcedconvection. The experimental data from Nielsen (1990), which represents a large room where the airenters horizontally at the top of one side and leaves the room at the bottom of the opposite side, wasused to validate the models. The mean velocity and the turbulence intensity profiles for Reynoldsnumber of 5,000 are presented in two planes of the room with two inlet arrangements.

In recent years, the control of airborne ions has become one of the important research items of indoorenvironment. Generally, it is quite difficult to get the sample of airborne ions, because their electriccharge might be discharged if they touch any surface. The authors considered that it would be possibleto evaluate how many of the sampled molecules had existed as ions in air, if the relationship betweenairborne ions concentration and its adsorption rate to the surface was clarified.

A study from 2005-2007 has been undertaken of 18 ‘low-energy’ dwellings in Milton Keynes, UK, originally monitored for temperature and energy consumption from 1989-1991. Results were compared under standardized daily external conditions of 5ºC. The follow

In Korea, there is growing interest in the remodeling of aged apartment buildings. Traditionally, theheating panel in Korea is a wet type floor heating panel that utilizes radiation. But if a wet type floorheating panel is installed in an aged apartment during its remodeling, some problems may occur. Theyinclude failure to secure enough ceiling height, to reduce level of floor impact noise and possibility thatthe load on the existing structure is increased.

This paper first introduces the concept of “exergy”, which quantifies what is consumed by any working systems from man-made systems such as heat engines to biological systems including human body. “Exergy” balance equation for a system can be derived by c

Application of night cooling to educational buildings looks very promising in mild climates. Night coolingstrategy performance in a school building to be realised in Italy during 2008 has been studied by meansof a commercial CFD code.Due to the symmetry of the building, first a 2D numerical model consisting of a vertical section throughthe three-storey building has been developed. The CFD model includes the solid zone describing theconcrete structure.

The objective of this paper is to apply a novel decoupling control method, direct feedback linear (DFL),to VAV air-conditioning system, which is differences from local linear decoupling control method. Amodel of VAV air-condition room is developed by a typical air conditioning system. Using DFL control,decoupling control is realized among multi-control loops in VAV air conditioning system and a linearmulti-inputmulti-output model is obtained. According to the VAV air conditioning model the real-timeDFL control system is designed and simulated based on MATLAB/SIMLINK.

In this study, we evaluated the effectiveness of sorptive building materials in reducing VOCsconcentrations in air using a small test chamber. Air containing a low concentration of VOCs wassupplied and any decrease in the VOCs concentrations was measured at the exhaust. Five differenttypes of building materials were investigated; activated carbon, gypsum board mixed with a givenquantity of activated carbon, board made out of activated carbon, humidity-controlling porous ceramicmaterial and ordinary gypsum board.

The energy penalty associated with the conditioning of large quantities of outdoor air in hot and humidclimates is well known. The problem is even more challenging when the application involved requires100% outdoor air. This is the case in an animal care facility, which houses different species ofanimals that are used for laboratory experiments in the field of life sciences. In such cases, it iscrucial that energy conserving HVAC systems be explored.