In newly built well insulated houses, a wind of 4 m/s will produce an air change rate of almost 0.3 h-1. However it is considered necessary to obtain air change rates of 0.7 h-1.
A steady state multi-cell calculation model has been developed in order to predict the interconnection between airtightness and ventilation rates. The model has been tested with measured leakage data of a detached house.
Undertakes a comparison of full scale and model scale internal velocities of naturally ventilated rooms. The FSEC Passive Cooling Lab, an experimental building with a fixed roof supported by columns, whose floor plan and ceilings are reconfigurable, located at Cape Canaveral in Florida, is the building used in this study. The full scale tests were conducted during evening and early night to provide an almost thermally neutral atmosphere, during February and March 1982.
Reviews the literature on wind tunnel modelling of natural ventilation. Lists advantages of using wind tunnels. Discusses strategies for utilizing natural ventilation. Describes the mean windspeed coefficient method and the wind discharge coefficient method of estimating natural ventilation for design of buildings in hot climates, and gives their advantages and disadvantages. Gives criteria for constructing wind tunnel models.
Ventilation and air exchange in buildings and industrial plants can be induced by external winds and by buoyancy forces. The dependence of the air exchange and heat transfer on a large number of factors, including the detailed configuration of the building and surroundings makes an analytical or numerical analysis of practical design problems impractical, particularly when both the buoyancy and the wind-induced pressures are of the same order of magnitude.
For optimum building design it is of importance to investigate the comfort and the energy conservation obtained with different types of ventilation systems and levels of airtightness of buildings. This could be achieved by aid of computer models based on full-scale and model measurements. In order to obtain experimental data as input data to such a computer model, an experimental, detached one-family house has been built near to Gothenburg on the Swedish west coast.
Measurements in a test room of 28.4 m3 located at the top of a 3-storey building have been made to determine ventilation rates of different natural ventilation systems. The systems under consideration were windows which are typical for residential buildings in Germany and various adjustable natural ventilation systems for installation in walls or window frames. The measurements take into account parameters such as inside/outside temperature differences, wind velocity and direction, opening position and location of thedifferent systems.
This paper discusses the potential for achieving an "energy-efficient" ventilation system by improving design procedures for natural ventilation. It considers ventilation requirements and the meaning of the term energy-efficient ventilation. Both of these topics are of fundamental importance to any design procedure. Natural and mechanical ventilation systems are discussed. This is done because natural ventilation is often compared unfavourably with purpose-built mechanical systems. It is argued that such comparisons can be misleading, unless all aspects are considered.
Natural and forced ventilation are directly and indirectly influenced by the pressure distribution around a building. Results of full-scale pressure measurements on a typical Swedish timber house are presented. The rate of air infiltration has been calculated by employing the values obtained from full-scale pressure distribution, air leakage characteristics and temperature differences. The results are compared with the actual ventilation obtained from tracer gas measurements.
Discusses insulation of lofts, roofs, walls, windows and floors, natural ventilation of dwellings and mechanical ventilation with heat recovery in dwellings. Considers cost benefits of weatherstripping and constant-flow ventilators for naturally ventilated houses. Concludes that installation of mechanical ventilation with heat recovery is uneconomic, but adding a heatexchanger to an existing mechanical ventilation system has economic benefits.
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