Reliable surface pressure and indoor wind speed data from model buildings in boundary layer wind tunnels can only be expected if appropriate modeling parameters are considered carefully. Modeling parameters to examine when planning boundary layer wind tunnel studies of indoor airflow and external surface pressures due to wind are identified, and criteria for assessment are suggested.
Two techniques for estimating natural wind airflow through buildings for comfort cooling utilizing data derived from boundary layer wind tunnel studies are presented. One method is based on pressure and discharge coefficients. The other uses wind speed coefficients determined from model studies in a boundary layer wind tunnel.
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.
Reports a case study dealing with the relation between ventilating and airing behaviour and the outside climate. Also the significance of other variables such as preferences with respect to the indoor climate are considered. Wind speed is found to correlate, but outside temperature (varying from -3 to +9 degrees C) does not correlate with the length of time the windows in the bedrooms and bathrooms are opened. Rainfall and sunshine also seem to have some influence. The main reasons for airing are that the bedrooms are too warm and not fresh.
This paper reports a case study dealing with the relation between ventilating and airing behaviour and the outside climate. Also the significance of other variables such as preferences with respect to the indoor climate are considered. An indication is found that wind speed correlates, but outside temperature (varying from -3 to +9 degrees C) does not correlate with the length of time the windows in the bedrooms and bathrooms are opened. Rainfall and sunshine also seem to have some influence. The main reason for airing is the opinion that the bedrooms are too warm and not fresh.
To update the National Association of Home Builders Thermal Performance Guidelines, models were developed, representative of the new houses being constructed in each American state. The models define the number and types of windows and doors,
Studies the direct coupling of ventilation heat and solar gains to increase the performance of passive solar systems. Examples of particularly suitable buildings are described. The thermal model FRED, based on a thermal resistance network representing a three-zone building, is modified to include a simple airflow model driven by wind speed and temperature difference. The simulated building is ascribed symmetric permeabilities, then asymmetric permeabilities.
Wind pressures on three Navy buildings at the Kanehoe Marine Corp Air Station, Hawaii were measured. Indoor and outdoor variables were also measured including temperature, dry bulb, wet bulb, relative humidity, wind speed, and wind direction. Pressure measurements were carried out using Validyne DP103 pressure transducers, and a static pressure probe. Natural ventilation is estimated 1. by combining window areas and pressure coefficients with wind speed and 2. using the LBL infiltration model.
Discusses the importance of local wind and temperature conditions and their effect on the air change rate between a building and its environment. Provides a descriptive model of air change rates and a building's microclimate. Describes methods which illustrate average wind velocity and effect of height and characterises wind spectra and turbulence intensity caused by velocity fluctuations. Discusses mechanisms which affect air change rates and climate comfort and gives an analysis of a simple model for random air leakage. Lists important and urgent research requirements.
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