Submitted by Maria.Kapsalaki on Mon, 03/21/2016 - 10:26
The trend toward minimizing ventilation of houses in order to reduce energy consumption for heating and cooling leads to an increase in indoor air pollution. The deterioration of indoor air quality (IAQ) negatively affects human health, safety, productivity and comfort. In order to evaluate the scale of this influence IAQ assessment has to be performed. However, the IAQ itself is not well defined and a number of parameters are considered as its indicators. In this work we compared carbon dioxide and volatile organic compounds as indicators of indoor air quality.
A field study was carried out to evaluate the effectiveness of air leakage sealing techniques for reducing air infiltration in houses. Presealing and postsealing air leakage tests were performed upon 82 single detached houses inWinnipeg or southern Manitoba. All houses were placed under a negative pressure, and leakage sites were identified using smoke pencils. Windows and doors were weather-stripped and other unintentional openings caulked and sealed using specified materials and techniques.
Several empirical models of house air infiltration, available from the literature, were reviewed and evaluated. Without exception, the limitations, inherent in these models, were found to stem from inadequate accounting of the interactive forces controlling air infiltration. In general, each of the available models was found to accurately reflect the specific real case used for verification, but extension of the model to other structures and situations was found to be totally inadequate.
The effect of ventilation in the space between a main wall and an exterior siding is examined with respect to reducing the building's cooling load. The buoyant force of the air in the space is considered as the motive force of air flow and the effect is treated as a problem of simultaneous heat and mass-transfer. A simulation program of heat and air flows in a wall has been developed using laminar flow theory, and its validity is examined by thecomparison of the simulation results with a weather exposed full-scale model test.
Use of spectral analysis as a tool in identifying correlations of annual and diurnal patterns of weather data is presented. Results obtained with the application of this technique to the 10-yr hourly data for six variables of Fresno, Calif., in the 1952-1963 period indicate significant correlations in the annual and diurnal patterns of the variables. A method is introduced for estimating coincident diurnal patterns, which can be used in load and energy studies. Considerations in selection of representative periods of weather data for standard usage are found to require further research.
A comprehensive computer program for the prediction of air flow and smoke migration in the building was applied to the 11 story administration building of the National Bureau of Standards. Natural air leakage rates under various climatic conditions for several ventilation system operations were obtained. The computed results were compared with measured air leakage rate by using the sulphur hexafluoride tracer gas technique. Smoke migration was simulated for the selected pressurization conditions.
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.