English

This paper discusses three methods for measuring interzonal air movements in two zone buildings: 1. initial injection of one tracer into a single room, 2. repeated injection of one tracer in two rooms, 3. initial injection of two tracers in two rooms. The description of these methods includes an outline of the theoretical background, the presentation of suitable injection strategies and algorithms for the evaluation of the concentration profiles.

Sustained efforts to conserve energy during the last 15 years have taken place at the expense of the indoor environmental quality. Ventilation air volume has been reduced to a minimum. The use of new materials, substances and equipment which emit gases, vapours, fibres and other pollutants into indoor air are and additional reason for the increasing frequency of complaints about the indoor environment. If air quality is improved by increasing air volume, the energy demand will increase - and extended initial costs will rise.

As part of the IEA Research Program Annex 18 "Demand Controlled Ventilation Systems" various ventilation systems were examined in a test room. During research, in addition to thermal comfort issues, removal of particles was of importance. In order to assess ventilation systems, besides using pressure - volume current graphs, the air exchange rate was frequently applied as a criterion. The air exchange rate is, however, defined only for gaseous components.

Ventilation performance of a vertical exhaust common-duct installed in a multi-story house was analysed using model experiment and computer simulation. Pressure losses at the flow junctions in the vertical common-duct were investigated using the model experiment. The pressure distributions along the vertical common-duct in three different multi-story houses of 5, 15 and 25 stories, respectively, were calculated by the computer simulation.

Keynote speech describes the difficulties of designing air conditioning system with human comfort in mind. Lists design fundamentals for satisfactory indoor air quality, together with a description of some case studies.

The predominant route for air movements between the floors of two-storey dwellings is via the stairwell. Such air movements are of significance in the assessment of building performance: for instance, it is possible that moisture could be transferred from ground floor areas to rooms on the first floor, resulting in an increase in condensation risk in such rooms. Several domestic heating schemes have been designed such that heating appliances are provided on the ground floor only; the upper floor relying on convective airflows for heating.

A new facility for the study of ventilation in buildings has been recently developed at the University of Basilicata (Potenza, Italy). This facility consists in a Controlled Ventilation Chamber (CVC), with an overall size of 2.4*2.4*3.0 m (the length may be extended to 4.2 m) . The CVC is divisible in two parts with a connecting door and is equipped with four grilles from which air can be immitted or extracted. A variable speed fan can adjust a flow rate of 0 to 10 ach.

The use of computers for data acquisition and analysis in air exchange measurements with tracer gases has become state of the art for the researcher. However, for air exchange measurements in the field, reliable operation of the equipment and the proper reporting of the results are still points of concern. Here, the computer can assist the user in the correct handling of the tracer gas equipment, in dealing with unfavourable measurement conditions, and in the production of a readable report.

This paper describes tests of thermal and ventilation performance of two relatively new occupant-controlled localized thermal distribution (also called task ventilation) systems. The first is a raised-floor distribution system providing air through grilles in the floor panels, and the second is a desk-mounted unit supplying conditioned air at desktop level. These systems have been tested in a mockup of a typical partitioned open-plan office, and the resulting temperature and air velocity distributions are reported for a variety of system and locally controlled conditions.

This paper treats the structure of models for predicting interzonal airflow and contaminant dispersal in buildings. It will discuss the mathematical structure of such models, the use of modem data structures, the application of structured program techniques and the use of object-oriented structures for the development of users interfaces and building description processes.