English

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.

In this paper, analysis of the ventilation requirements of enclosed vehicular parking facilities is discussed. First, a compilation of existing U.S. and international standards and codes pertinent to the ventilation of enclosed parking facilities is presented. Then, the results of a field testing study are summarised to determine the actual ventilation rates and the contaminant levels in seven U. S. enclosed parking garages. Finally, this paper presents a new design method that provides the minimum ventilation rate requirements for enclosed parking facilities.

In this paper, a zonal model used to predict the air movement, temperature distribution and airquality in a room is presented. It is based on a rough partitioning of the room: it is anintermediate approach between one-node models (that consider an homogeneous temperaturein each room, and, for that reason, do not permit to predict the thermal comfort in a room) andCFD models (that require great amount of simulation time). Where plumes, jets or thermallayers occur, air flow is described by empirical laws.

In the beginning of 1998 the European project, AIRLESS, was started to develop strategies,principles and protocols to improve and control the petiormance of HVAC-systems and itscomponents for the incorporation in codes and guidelines. The project is divided in 6 tasks.The Hermann-Rietschel-Institute deals with the second task of the project, the maintenance ofHVAC-systems. People stay approximately 90% of their lifetime in enclosed rooms. Theserooms are often served by HVAC systems. In recent years poor indoor climate has causedhealth problems in buildings.

The pattern of airflow influences the propagation of airborne pollutants, the thermalenvironment and general comfort conditions. In designing a good HVAC system, it isideal to determine the airflow distribution in the occupied zone to ensure good quality ofair and comfort condition are provided to the occupants. In most instances, it may not befeasible to conduct such study experimentally. This paper presents an investigation on thepredictions of air movement within a room and compared them with the physicalmeasurements.This study is carried out in a seminar room at a University.

During the last decade, an increasing interest in Underfloor Air-Conditioning (UFAC) systems has emerged. This is due mainly to an increased demand from employees for a greater control over their working environment. And the building and its engineering systems not only have to be designed to achieve the high standards of environmental control at economical cost, but also thermal comfort is an important factor that influences occupants' satisfaction with the indoor office environment.