wind

Discusses the possible effects of wind, stack effect, vents and fans on air leakage, and the influence of air leakage openings and the location on the pattern of air flow through buildings. Considers the possible extent and location of condensation in relation to these patterns, as well as methods of controlling moisture entry and removal of accumulated moisture.

States that comparison of different methods of calculating the volumes of outdoor air entering a building through the window shows that the chief deficiency of the standardised method of calculation is neglect of the importance of the relation between building dimensions, the wind profile andthe resulting pressure distribution at the building. Proposes an approximation method which significantly improves the accuracy of the calculation and also permits the calculation of flow through buildings for each possible combination of the factors determining the flow.

Describes a study to map the ground wind conditions in the housing area Kroksback in Malmo, and to study the effect of various proposed measures to improve the wind environment. Studies local ground wind conditions by field measurements using the Swedish Institute for Building Research (SIB) mobile measuring unit and by comparative model tests in the SIB wind tunnel laboratory. Estimates wind speed and direction by means of a simple indicator device.

Measures air change rates in a 2-storey detached house with operation of various types of mechanical fresh air ventilation systems. Studies 4 systems, including 2 balanced systems and 2 exhaust-only systems. The forced ventilation rate is controlled at 0.15, 0.25, 0.4, or 0.5 ach. Develops expressions for the test house relating the house air change rate under winter conditions to the forced ventilation rate and the infiltration rate due to wind and temperature difference.

Correlates hourly infiltration in 3 adjacent unoccupied test houses to determine the relative contribution of wind and stack effects. The database, obtained using tracer gas techniques over 2000 hourly readings in each house, is sorted to a single 45 degree sector. Different weather sealing techniques give mean infiltration rates of 0.19, 0.45, and 0.59 ach for the 3 houses. Addition of independent wind and temperature induced pressures correlate only part of the weather induced data variability leaving a residual RMS scatter of about 0.004 ach.

Describes a test method for determining the overall heat loss coefficient of a house. Bases method on the statistical correlation of measured heat consumption with outdoor weather data. Derives a regression equation from the heat balance giving the relation between indoor air temperature, internal heat production and the outdoor weather data. Continuously monitors the power consumption (from electrical heaters) in an unoccupied house, together with indoor air temperatures and outdoor weather data, as solar radiation, outdoor air temperature and wind velocity.

Gives a survey of the weather parameters used for the "Danish test reference year TRY" and the corresponding set of data from meteorological observations made during a 15 year period. Describes the measuring methods used for the most important weather parameters, and presents selected tables and diagrams with some of the most important weather data. Gives possible fields of application for the test reference year.

Describes the major features of air flow around buildings, indicating how wind characteristics and building geometry interact to determine airflow round a house. Outlines work being done by Watson House in this area, mainly concerned with ventilation, flue performance and dispersal of combustion products.

Describes the relationship between wind flow round a building and heat loss from it. The relative merits of numerical and wind tunnel models are discussed and various numerical techniques, including the vortex method and the control volume method, are examined.

Briefly reviews the study of wind flow around buildings. Shows that fundamental theoretical and experimental studies are beginning to produce simple descriptive and mathematical models of flows round buildings. These should enable designers to predict the general features of wind around a proposed building or group of buildings at an early stage in the design. Gives some examples of these models.