Characteristics of the air velocity were measured at 500 points in the occupied zone of 20 typically ventilated spaces. A relationship between the mean velocity and the standard deviation was found at four heights above the floor. The turbulence intensity varied from 10 to 70% at ankle level (0.1 m) and from 20 to 55% at head level. This is similar to the experimental conditions under which the draught chart by Fanger and Christensen was established.
Discusses guidelines produced for the Nordic Ventilation Group. Explains how the designer can select an effective ventilation system on the basis of information on ventilation rates and ventilation efficiency.
Investigates the effects of five different ventilation strategies on the annual energy consumption for heating and warm water of residential (family) homes. The strategies are: (1) natural ventilation, (2) mechanical ventilation and three forms of exhaust plants. Uses weather data from Portland, Oregon and Great Falls, Montana as examples of very different climatic conditions and heating/cooling requirements. The University of Wisconsin TRNSYS program was used for numerical simulation.
Measurements of the radioactive subsoil inside a closed and air conditioned room were made to establish how far the concentration of radon and the radon daughters may be changed by means of ventilation. Whereas the radioactive subsoil in a building cannot be influenced due to the given cosmic radiation and the radio-active isotopes, it is generally assumed that the radio-activity originated by Radon 222 may be removed from the room air by ventilators. The radon diffusing from the brickwork disintegrates into several intermediate radio-active products and finally into stable lead.
To make an evaluation of ventilation systems, numerical computation was carried out for three dimensional, isothermal, and turbulent flow schemes. It was found that there exists an optimum position for an inlet in relation to an outlet whereby the most effective ventilation can be attained. In addition, similar to the results for the two dimensional computation, the slope of the concentration decay is virtually constant and independent of the position in the room, so the mixing factor derived from this slope can be used as an index of the ventilation efficiency.
Describes a demonstration project to show that, in well sealed houses, trickle ventilators can provide an opening large enough to reduce condensation and odour problems, but small enough to avoid any significant increase in energy use.
Discusses methods of preventing condensation: dehumidification, ventilation, controlling vapour flow; insulation and heating. Particular attention is paid to interstitial condensation and condensation in roofs
The advantages and disadvantages of various ventilation systems have been assessed in Germany over the past four years. The programme covered research in unoccupied test rooms as well as in occupied buildings. Results are presented, and the possibilities and limits for energy saving while meeting comfort requirements are discussed.
In order to determine ventilation performances in hot arid regions a transient program was simulated for a single room with glass windows. The calculations were done on climatic data of a typical city close to the central desert of Iran. Results indicate that the incident solar radiation to the room has a high influence on the room air temperature.
Evaluates results of the 'Ventilation in Residential Buildings' research programme of the German Federal Ministry for Research and Technology. It was found that conventional ventilation methods based on infiltration and window opening cannot secure proper air quality and at the same time provide energy conservation and user comfort, nor can intelligent ventilation habits be expected of the average user, for subjective and objective reasons. All ventilation systems evaluated had shortcomings.
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