Measurements of air flow and microorganism concentration have been made in the stair shafts of a hospital, using a diving bell-type of pressure-recording instrument, and a sampler for the microorganisms, respectively. Results of experiments were used to calculate the flow rate of microorganisms between the floors of the hospital. A mathematical model based on simplified transport equations is proposed, which would allow the prediction of the flow field and the distribution of microorganisms in the stair shaft.
A multi-cell calculation model was developed for calculation of the interconnections between airtightness, air change rates, pressure conditions and energy consumption. The flow equation used in the model is quadratic, which can be used as well for a single leakage path as for a whole building envelope. For energy calculation the area of wind directions is divided into12 sectors (each 30 degrees) plus one sector for calm wind conditions. The mean values of wind speed and outside temperature applied to each wind sector are calculated from weather data of several years period.
Discusses the requirements of air supply installations in high-occupancy spaces. Describes the characteristics of different systems of air diffusion, illustrates them and their operation in diagrams and photographs and demonstrates the nature of the room air flows created by them. Lists and discusses the advantages and drawbacks of air introduction from chairs and desks, from pivoting nozzles in walls of galleries and from ceiling or floor diffusers.
Describes factors to be taken into account for air conditioning and heating in a theatre. Nature and purpose of the building call for an adequate supply of conditioned outdoor air, with a total supply air rate up to 69,000 m3/h. Economical use of energy was stressed. Detailed description of the problems involved with the auditorium and stage shaft are given.
A study was made of one hundred subjects who were exposed to air flow with a turbulence as occuring in typically ventilated spaces. Turbulent air flow is seen as more uncomfortable than laminar flow. Each subject participated in three experiments at air temperatures of 20, 23, and 26 degrees C, withvarying air velocity and turbulence intensity. Recommends a reduction of velocity limits specified in existing standards.
The introduction describes the principle of SVP (Solar Ventilation Pre-heating) and then reviews a number of current related topics. Heat recovery is considered. Work on other devices which produce solar heated air is reviewed. The main driving forces of natural ventilation are wind pressure and thermal buoyancy. One of the problems is that the magnitude of these forces is very variable. The basis of SVP demands a thorough knowledge of airflow through buildings.
Describes the network procedure for calculating the most energy-conserving and economical form of natural ventilation of a building. Provides application examples in the form of the determination of mass air flows through doors and windows and cracks in industrial work sheds. Provides the results of a calculation of crack ventilation in winter with mechanical ventilation with positive pressure, plus optimisation of air flow through a cooling bed for hot rolled steel sections.
There is no patent solution. Discusses duties of ventilation system: to create a satisfactory indoor climate in a cost-effective manner while considering the demands of three intimately associated factors - well-being, health, working efficiency, risk. Notes the various criteria to be complied with to provide satisfactory ventilation: thermal requirements, air quality requirements, noise/safety, flexibility and economy.
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