This investigation is part of project NATVENT TM, a concerted action of nine institutions of seven European countries under the Joule-3 program. It aims to open barriers that blocks the use of natural ventilation systems in office buildings in cold and moderate climate zones. The choice to apply natural ventilation in office buildings is very arbitrary; it depends very much on the personal preference of the architect or taken for budgetary reasons, even sometimes not considered at all.
Perceived barriers restricting the implementation of natural or simple fan assisted ventilationsystems in the design of new office type buildings and in the refurbishment of existing suchbuildings have been identified in seven central and north European countries with moderate orcold climate: United Kingdom, Belgium, The Netherlands, Switzerland, Norway, Sweden andDenmark.The barriers were identified in an in-depth study with structured interviews based onquestionnaires among leading designers and decision makers: architects, consultant engineers,contractors, developers, owners and governme
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.
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.
The performances of self regulating natural ventilation devices (devices of which the openingsection varies as function of the pressure difference across the device) strongly depend on thetype of building and its leakage characteristics. In like manner, the climatic conditionsstrongly impact on the achieved ventilation rates. As a result, it is not possible to express thepotential benefit of self-regulating natural ventilation devices in an unambiguous way. This isnot contributing to a good understanding of the potential of such devices in daily practice.
There are certain conditions which are of interest when designing for natural ventilation ofcommercial buildings. These are:- summer cooling- indoor air quality in winter- night-time cooling.For the first two conditions it is necessary to determine the distribution of open areas to givethe desired distribution of flow rates. Since one is dealing with openings whose position andbasic geometry are known, the problem is relatively simple compared to general ventilationproblems.
This research is part of project NATVENT (TM), a concerted action of nine institutions ofseven European countries under the Joule-3 program. It aims to open the barriers that blocks theuse of natural ventilation systems in office buildings in cold and moderate climate zones.Natural night-time ventilation cooling is a very effective means to remove the heat,accumulated in the building fabrics during office hours. Moreover, it requires no energy at all.Cooling with natural ventilation has it limits; more than 6 air changes per hour have no morecooling effect.
A difficulty when designing natural ventilation in office buildings is the lack of simple designtools.In order to be able to predict natural ventilation air flow rates and indoor air temperatures atthe design stage, a computer model has been developed within the EU-JOULE projectNatvent (TM). The program is an integrated model with a thermal and an air flow modelcoupled together.
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