PR1999

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.

Until now, there is no widely accepted way to express any index for this purpose and takinginto account the large variety of possible pollutants. Things can be simptied if the aim k tocompare different systems and strategies rather than to give an absolute value of quality.For the study of a pollutant source, the main important point for comparison is the pattern ofits production, whatever this pollutant is. The detailed data for each inhabitant is the curve ofthe number of hours above a pollutant level concentration.

House-dust mite antigens are a major contributor to allergic sensitisation. Since temperatureand humidity are crucial to house-dust mite physiology, there is considerable interest inreducing mite populations by controlling the indoor environment.

The energy saving practice of stopping ventilation systems at night may reduce the daytimeair quality. Sorption phenomena where pollutants absorbed at night are reemitted during theday and the general slower removal of pollutants at the reduced average ventilation rates willcontribute to the deterioration of air quality at intermittent running systems. The purpose ofthe study was to investigate the impact on construction product emission during the day fromreduced ventilation rates at night. Experiments were performed in three small-scale chambersof Climpaq type with dilution systems.

The Netherlands Agency for Energy and the Environment(NOVEM) is conducting a program for the implementation of Low Temperature Heating (LTH) systems in buildings. The primary goal is to enable the use of Low Talued Energy as a heating source. Major savings in enery consumption can be realised by fully utilising the potential of Low Valued Enery. Besides the argument of savings in energy supply, there are additiond benefits in the fields of. Indoor Air Quality (particles, mites, lower air temperature, annoyance and dust);.

In a cold climate such as of Montreal the air infiltration through the exterior envelope of a house has a significant impact on the heating energy consumption and cost. Although the reduction of the air infiltration rate to the level of new well-built houses can lead to the reduction of heating energy cost, the present cost-effectiveness of its implementation in the existing houses is low. The evaluation of the environmental impact of this energy conservation measure is performed using the GWP (Global Warming Potential) index.