English

In order to be validated, the computer programs simulating the air flows in multizone buildings need several measured data sets to be compared with. Such a set was measured on the LESO, a mid-sized administrative building. This set contains: a) The permeability coefficients (C,n) of the building obtained by guarded zone pressurization b) Pressure coefficients Cp measured in windtunnel and on the real building c) Tracer gas air flows measurements d) Corresponding weather data for two periods of 10 days on the non inhabited building.

Ventilation, infiltration, indoor air flows and air exchanges determine two aspects of fast growing interest: the energy balance of buildings and the indoor environment. Whilst in the wages of the energy crisis RD (research and development) & D (demonstration) in the different areas had been focused on rational energy use now with view on the public awareness of the environmental situation (outdoors and indoors) also the aspect of indoor air quali ty stimulates widespread RD&D activities.

VAV - air conditioning system makes it possible to control indoor conditions even when the heat loads are changing. But this is possible only when each part of the system works as it is intended to work. When the air flow varies in a large range, it can cause situations, where pressure loss of some flow dampers are out of their operating range. This is possible especially whenthe system is large and the velocities are high. This means that the air flow is not correct. Also increasing noise levels may appear.

This paper describes a simulation program which was developed for the modelling of air-conditioning systems and conditioned spaces in industrial buildings. The program can be used for a design of systems for new buildings and for analysis of existing ones. By viewing the building as a dynamic entity, it is possible to investigate how thermal capacity of the building elements acts on both the conditioned space and the performance of the air-conditioning system. The program simulates three important aspects of a building.

The use of passive perfluorocarbon technique for air flow measurements has been developed and tested. The building and testing of the system took approximately one year. The reproducibility of the analysis was tested during the period. The results show that the relative standard deviation of the analysis for parallel samples is less than 7 % for each tracer in most of the cases. A drift of calibration was noticed, but it can be allowed for by using reference samples with known amounts of tracers. The accuracy of the method was tested in controlled laboratory conditions.

The indoor climate and ventilation were measured in 50 dwellings with various ventilation systems. The health and comfort of people living in the dwellings were studied with a simultaneous questionnaire. The ventilation rates measured with a tracer gas using the decay method varied from 0.1 to 1.2 m³/hm³, with an average of 0.5 m³/hm³. The ventilation rate in the bedroom was usually lower than the mean ventilation rate of the dwelling. The ventilation rates measured in a two-week period with the passive perfluorocarbon method varied from 0.2 to 1.9 m³/hm³, with an average of 0.8 m³/hm³.

A new visual method is yielded by a particular application of Mollier's h,x-diagram. Point fields (temperature and humidity) lead to a significant improvement upon previous graphic methods. Flats with mechanical balanced ventilation are drier and more influenced by the exterior climate than are with shaft ventilation system ventilated flats ("Berlin ventilation"). The evaluation of the graphic representation of the experimental results in the form of curves permits rapid assessment of the experimental results.

This paper presents a new technique for supply of outdoor air directly through external walls into a dwelling room without any draught problems. A new type of air inlet unit has been developed based on the experience from the study of indoor climate in the " Stockholm Project" . This Swedish experiment including six new residential buildings, where the indoor climate together with different solutions for ventilation is evaluated, shows that draught from air inlets is one of the greatest problems with bad indoor climate.

This paper presents and evaluates a new method, based upon tracer gas techniques, for determining interzonal airflows and effective volumes in a multizone enclosure. Presently used tracer gas techniques have a number of drawbacks including the need for multiple tracers when analyzing a multizone structure. Also, traditional techniques cannot be used to independently determine flows and volumes in the multizone case. The method described in this paper eliminates some of the problems introduced by multiple tracers and allows the independent determination of both flows and volumes.

Moisture and mould in buildings have become fairly common problems in Italy, particularly since regulations aimed at energy conservation have been enforced in the seventies. Results of a case study conducted within IEA Annex XIV are presented in this paper. Two flats belonging to the same building (one with and the other without moisture problems) have been monitored during the winter 1987-88. Indoor temperature and air humidity, wall surface temperature and weather parameters were recorded for several weeks using two automatic data loggers.