English

This study reports on the introduction of air infiltration and mechanical ventilationin a model for energy consumption estimation. The model applies to air conditionned nonresidential building and is developped to need few inputs. Existing air infiltration models arecompared and three equivalent leakage area (ELA) databases are tested on the same casestudy. Calculations of air input throught opened-doors are made to compare flows due to airinfiltration and due to natural ventilation. Simulations are made considering mean airinfiltration value and hourly values.

Many post-war residential buildings in the Netherlands have collective heating systems with poor energy efficiency. Also ventilation and DHW systems usually do not comply with current requirements. In Heerlen, the Netherlands, a demonstration was carried out in the framework of the EC-THERMIE programme in a residential building where the collective heating, DHW and ventilation systems are replaced by individual multi-functional appliances. These appliances are a recent development in the Netherlands, integrating different service functions.

This paper considers the role of passive stack chimneys in controlling indoor thermalconditions in the vernmlar houses on the volcanic island of Santorini . The quality of theenvironment within these dwellings is disputable, mainly because of the high humidity levels.A monitoring study was carried out in four actual dwellings in Santorini, two built on thesurface and two excavated into the soft volcanic rock. The temperature and relative humidztyof their main space and their chimneys were monitored and compared to the simultaneousexternal conditions.

This paper identifies the significance of pollution at five sites amongst the worst on the British mainland hence indicative of other polluted areas within Europe. Three sites are located in London and one each in Birmingham and Cardiff. The pollutants examined are NO2, SO2, O3 and PM10. Newly proposed DOE figures defining poor air quality have been used to re-examine the frequency of excess pollution episodes between 1992-1995. The results identify the most appropriate periods for natural ventilation of offices in urban areas in terms of the hour in a day and time of year.

Within the EU project NATVENT, which deals with the application of natural ventilation in office type buildings, one of the items to be studied was controlled air flow inlets. Natural air supply is a key part in the design of natural ventilation in offices. In cases these air supplies are designed in the wrong way one may expect complaints in terms of draft and stuffiness. Size and controls on inlets are vital elements in design. Controlled air inlets may help to overcome the problems of draft and stuffiness, and may contribute to an energy efficient design of the building.

An extensive experimental program on single sided natural ventilation was carried out within the frame of PASCOOL EC research project. Within the frame of these activities, four single sided natural ventilation experiments were carried out in a cell test, a full scale outdoor facility. Experimental data were used as input for numerical simulations that were carried out using air flow calculation tools based on network modeling as well as computational fluid dynamics (CFD). Finally, fuzzy logic techniques were used to predict the air velocity profile in the middle of the opening.

In the framework of the Flemish Impulse Programme on Energy Technology (VLIET), the project called SENVIVV is running from January 1995 till September 1997. The major objective is to obtain a detailed picture of various characteristics of dwellings constructed during the period 1990-1995. To achieve this, a representative sample of 200 dwellings is analysed in detail. The final report of this project is expected to be available at the end of 1997.

A model for the application of probabilistic methods is the estimation of heat loss caused by convection and heat conduction through the material is developed. Temperature difference (delta T) between inside and outside of a building, air change rate (ACH) and coefficient of thermal transmittance (U-value) of the building structure are treated as random variables. The mean value and standard deviation of heat loss are estimated for different parameters of distribution for temperature difference, air change rate and thermal transmittance.

This study aimed to research the airtightness of the building envelope in apartments before and after renovation. Measurements were carried out in three apartment buildings. One to four apartments were examined in each building. Typical renovation measures included changing the windows and refurbishing the interior surfaces. In some cases the ventilation system was renovated as well. No special emphasis was placed on the sealing of the envelope. The airtightness of the apartments increased in most cases. There were, however, apartments that became leakier during the renovation.

This paper discusses summer cooling of buildings by means of natural ventilation. Computational fluid dynamics is used to predict the ventilation rate in a room with a Trombe wall. The effect of Trombe wall insulation on the room thermal environment is investigated. It is shown that to maximise the effect of ventilation cooling, the interior surface of a Trombe wall should be installed.