The paper presents results of ventilation characteristics of a lecture/seminar room obtained by various door-window opening combinations and positions, and the level of comfort and air quality resulted by the given window-ventilating modes. Applying statistical methods, formulae of air change rate for the test room under it's normal operating condition i.e. when all window and external door are shut and when particular windows are opened is also presented and graphs in relation to dominancy factors such as wind and buoyancy effects, are given.
A single whole building pressurisation test using robust and easy to use equipment can, in a very short time, quantify the air-leakiness of the building envelope. However, such measurements do not give a direct measure of the ventilation characteristics of the building which normally requires timeconsuming and specialist tracer gas tests. This paper provides a model which makes the link between leakage measurements and ventilation characteristics and applies it to a large, industrial building constructed according to 1979 UK Building Regulations.
The controllability of room air temperature in different heating systems connected to demand controlled ventilation systems was studied. Studied ventilation systems were exhaust, supply and exhaust and a system with exhaust and an individual supply to each apartment. Studies were made using PIPNET-simulation program package. It is designed to allow detailed simulation of entire building systems: the building shell, heating and ventilating plant and the dynamic thermal interactions among the subsystems. First single zone calculations were performed.
A set of reporting guidelines has been established. The guidelines take into account the need for data concerning airflow within buildings and air exchange between a building and its surroundings. They also deal with issues such as pollutant production and transport, thermal properties and measurements of buildings and comfort related issues. The comprehensive nature of these guidelines should enable a large amount of data to be accrued in a form suitable for computer modelling and validation work.
The paper summarises the IEA, Executive Committee on Energy Conservation in Buildings and Community Systems, Annex 14 work on Condensation and Energy, a joint research effort of the Federal Republic of Germany, Italy, the United Kingdom, the Netherlands and Belgium, finished end of march 1990. First the complex relations between mould+ surface condensation, the outside climate, the building fabric, inhabitants behaviour and energy conservation are discussed. Then follows a short overview of the Annex achievements with mayor emphasis on the guidelines and practice results.
Demand controlled ventilation systems have recently become an interesting opportunity to achieve acceptable indoor air quality while minimizing energy consumption. Although they are usually designed for buildings showing relevant variations of occupancy (e g, office buildings, schools, etc.), there are now examples of applications also in residential buildings. One example is the passive humidity-controlled ventilation system recently developed in France. This type of installation has been tested in a five- storey apartment building located in Torino, Italy, during the winter 1989.
Turbulent flow fields of velocity and diffusion in several types of mechanically ventilated rooms are precisely analyzed both by model experiment and by numerical simulation based on the k-s two-equation turbulence model. The detailed analyses of contaminant diffusion by simulation make it possible to comprehend clearly the structures of velocity and diffusion fields in rooms. The flow fields in such rooms, as analyzed here, are mainly characterized by the inflow jet and the rising streams around it.
The ventilation system described here combines a central air shaft in the hall area with a mechanical waste air extraction system in the bathroom and in the kitchen. If there is a large amount of moisture in the dwelling, the volumetric flow of thewaste air fans is increased, the increase being controlled by means of hygrostats. This ventilation system ensures adequate ventilation of the dwelling. In dwellings without a supply air shaft, this hardly applies any more with the installation of windows with very low joint permeability.
As a consequence of measures required for reducing the heating energy consumption in residential buildings , there have been more and more complaints in the last few years on the appearance of mould in dwellings . In most cases, it is retrofitted or renovated old buildings which are affected [1]. Mould growth is frequently the result of a severe reduction in the natural air change rate in old buildings following the installation of airtight windows, while user habits remain the same as before.
Mechanical ventilation system performance involves the provision of adequate amounts of outdoor air, uniform distribution of ventilation air within the occupied space, and the maintenance of thermal comfort. Standardized measurement techniques exist to evaluate thermal comfort and air exchange rates in mechanically ventilated buildings; field techniques to evaluate air distribution or ventilation effectiveness are still being developed. This paper presents field measurements of air exchange rates and ventilation effectiveness in an officepibra-y building in Washington, DC.
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