When taking measures to increase energy effectiveness it is important not to deteriorate theindoor climate. In the present study a Computational Fluid Dynamic (CFD) model was builtto investigate temperature and airflow patterns in a Swedish low-energy building. A full-scalemodel of the house has been generated in the commercial code Icepak 4.1. The commercialCFD code Fluent 6.2.16 is used for the numerical solution. The RNG k-e model is used asturbulence model.

To properly evaluate the performance of ventilation system, the interaction among ventilation rate, indoor air-quality, and cooling/heating load should be analyzed. In this study, an integrated simulation tool based on TRNSYS will be suggested to analyze the performance of ventilation system. Some modules to calculate the changes in indoor concentration of pollutants with ventilation system and to decide the operation mode of ventilation system were newly developed. In addition, the developed modules were coupled with building load and heating/cooling simulation modules.

Air handling unit (AHU) is defined as a self-contained unit that the conditions of air vary while passingthrough it and reach to the desired temperature and humidity. To perform variations in weatherconditions various processes such as heating, cooling, humidification, dehumidification and mixing are applied. In this research thermodynamic modeling and mathematical optimization of air handling units approaching minimum energy consumption is achieved. The objective function for optimization is pressure drop of air crossing coil per cooling and heating load of the system.

In modern apartment buildings with good insulation and heat recovery, often having large windows and high internal heat gains, overheating may be a serious problem not only in summer season, but also during heating season. This study determined the design curves for the assessment of room temperatures and cooling demand in apartments. The design curves are based on many simulations and they show the effects of window airing, solar protection glasses, window size and orientation, cooled supply air and room conditioning.

Field tests of a proposed efficient air flow model calibration method were performed on twoclassroom/office buildings. Models developed using CONTAM multizone software were tuned via an iterative procedure that sought to maximize the fraction of correctly predicted interzonal flow directions. Site measurements during a concentrated period of testing, including HVAC air flows, envelope leakage, and site weather data were used to update the multizone models.

Due to high-rise residential buildings and extension of balcony, to resolve discomfort ofindoor-environment and the problem which energy consumption increases, high-riseresidential buildings, coming natural ventilation and decreasing expense of an airconditioningsystem., enable envelope system to be developed.The object of this study is to present the improvement on envelope of high-rise residentialbuildings to reduce heating and cooling load.

Field survey in the M-Office which installed Task/ambient conditioning systems (hereinafterreferred to as the TAC) was conducted in 2005 and 2006. It was intended to investigate theinfluence of the worker's behavior and task-conditioning to workers comfort sensation. Inthis survey, immediately thermal environment and workers behavior were measured, andquestionnaire to occupants who worked as usual were conducted. We found that both activitylevel of occupant and exposed thermal environment is greatly different one by one.

A subjective experiment was conducted using 15 college-aged subjects of both genders in order to evaluate their physiological and psychological reactions, performance and fatigue under the different combinations of indoor humidity, local air velocity and illuminance.

The purpose of this study is to evaluate the relevance of household characteristics on exposure time to CO2 in houses with balanced ventilation. Statistical tests were conducted to measure the significance of household differences on time indoors. Household scenarios and ventilation scenarios were constructed to determine the level of CO2 indoors. The production of CO2 was calculated with the metabolic rate per age of the members of the household. Households are exposed to levels of CO2 higher than 1000 ppm in houses with low infiltration rate.

Due to criteria for building energy efficiency today’s buildings are better insulated and the envelope is more air tight. These improvements have led to a more comfortable buildings and lower running costs. However, the new indoor environments are more de