PR1999

The ventilation engineer's plan at the design stage could be influenced by many factors. It may also be different from the requirements for the final users of the spaces. In case of open-space design, which is getting popular due to its flexibility. It is more difficult to provide adequate ventilation to control the indoor air quality. Specially, when partitioning of the space is employed.

Recently well-insulated and well-airtightened houses are increasing in Japan. Those houses havesome problems of air quality because of formaldehyde from construction materials. Ventilationsystems have possibility to solve these problems. The authors have developed a simulation programfor designing building elements, equipment elements to keep balance among comfortabletemperature and humidity, good air quality and energy conservation. The effects of some ventilationsystems in multiple dwellings are revealed by the developed simdation program.

The objectives of thisinvestigation were to examine the dynamic water vapour sorption offurnishing materials and to compare the experimental results withpredictions obtained from the Moisture Admittance Model. Dynamic sorption measurementswere carried out for common building materials. The measurements were made by placingspecimens of the materials in a humidity chamber and varying the ambient humidity between46% and 90% RH at constant 22C. The weight of the specimens was monitored in situduring this procedure.

There is a growing demand for buildings to have a high indoor air quality environment. Twoof the main elements that contribute to this quality are temperature and air distribution withinthe occupied space. In modern office buildings particularly in hot climates, care must be takento design the most economical air distribution system that provides comfort for the occupants.There are many techniques available to predict the air distribution patterns in the space atdesign stage, but these are often not very accurate.

Few detailed comparisons of modeled ad measured pollutant concentrations in multizonebuildings have been published. The COMIS air flow and contaminant transport modelpermits simulation of the effects of building and HVAC operation, as well as the influence ofthe local meteorology, on air flows within the building. We have recently used this model tosimulate the release of a gas-phase tracer in a three-story, multi-room building located atDugway Proving Ground, Utah, USA.

There are often tradeoffs among improving IAQ (Indoor Air Quality), maintaining thethermal comfort, and reducing energy consumption for HVAC (Heating, Ventilating, and Air-Conditioning) systems. A prediction model that can simultaneously treat these factors isrequired to realize good design of sustainable buildings. For this paper, a concept of OccupantContaminant Inhalation is used for long-term assessment of IAQ. A long-term evaluationindicator for other factors such as air temperature is also introduced (Occupancy-weightedAccumulated Deviation from thresholds).

With increasing demand for acceptable indoor environment it is necessary, already in theconstruction phase, to estimate what effect different environmental factors have on theoccupants. Thermal sensation is affected by many factors of the indoor environment.Predictive models are available which describe overall thermal sensation as function of themost important factors. In this work reference environments have been investigated with athermal manikin. The results from these measurements are then compared to CFDpredictions.

Results are presented from a study of the performance of fuzzy, rule-based algorithms for thecontrol of indoor air quality through combined control of natural and forced ventilationstrategies, whilst simultaneously meeting thermal and visual comfort requirements as part of aglobal control strategy aimed at optimizing the indoor environment with minimum energyconsumption.

Parametric studies have often been used for sensitivity analyses in the field of the pharmaceuticaland agricultural sector. All such studies aims at bringing some kind of order out of complicatedrelationships between influencing factors and some response parameter(s). With experimentaldesigns and statistical analysis methods, it is possible to trace and quantify influencesof individual as well as combinations of input factors on the response parameter. Thisprocedure has so far very seldom been used within the building sector.

New thermodynamic energy "water potential" based on the chemical potential of a component of mixture gases is defined as the driving force of gaseous phase water flux. Adhesive power, which is a kind of stress call "capillary attraction" and a part of the water potential, is proved as the driving force of liquid phase water flux. Then numerical model of coupled heat and water transfer using the water potential is introduced and influences of stress such as gravity and stationary pressure on water flux are clarified from the viewpoint of thermodynamics.