Discusses the sources of radiation exposure for the population of the UK. Radon is the most important natural element. Presents results of national and regional surveys. Remedies and preventive measures are outlined and protection standards are suggested.
Describes experiments to measure the ventilation rates of two small open-plan factories, one typical of current design and one designed to be more energy efficient, with increased levels of insulation and a tighter method of construction. Air leakage rates were measured using the Watson House Leakage Tester, and ventilation rates were monitored by the Watson House Autovent System. The problems involved are described, and how they were overcome in this case.
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 ventilation requirements to achieve acceptable air quality. In many cases, this would lead to unacceptable energy costs, so instead recommends setting standards for heat-exchanger systems, for filters that can control particulates, hydrocarbons and radon gas, and for details such as flow direction and system maintenance. Also standards for 'pollustat' systems should be encouraged by which four surrogate pollutant levels would be kept below suggested threshold levels in all conditions of building use and occupancy.
Discusses methods of preventing condensation: dehumidification, ventilation, controlling vapour flow; insulation and heating. Particular attention is paid to interstitial condensation and condensation in roofs
Discomfort due to stuffiness and adverse temperature gradients may occur in well insulated rooms with low levels of natural ventilation. Using methods previously applied to studies of convection in the atmosphere, a model of the room air movement
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.
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