wind

Analyses wind pressure records, taken during 5 different windstorms on 2 levels in a 400ft (122m) high office building in downtown Montreal March 1964 pressure fluctuations on an actual building. Preliminary work done to compare full-scale measurements with wind tunnel measurements indicates that simulation of basic statistical properties of wind pressure fluctuations can be successful when carried out in a boundary layer type of wind tunnel.

Gives the results of measurements of wind and driving rain carried out over a 1-year period on an 18-storey block of flats, and compares these results with calculated and model scale data. The in-situ measurements indicate that the pressure differences between various locations on a facade, exposed to rain are much smaller than the calculated values, and also pressure differences due to wind at a window between the inside and outside are much lower than the theoretical values.

Presents a review of the problem area relating to unintentional ventilation, with special reference to the significance of this phenomenon with regard to the heat balance of buildings. It also contains a list of research tasks which the authors consider to be urgent. Factors which affect unintentional ventilation are discussed, such as wind and temperature conditions outdoors, permeability of the climate envelope of buildings, flow conditions on rooms with known rates of air supply and known temperature conditions, air movements in a flat and in the entire building.

Describes measurements of airtightness and ventilation in prefabricated 'modulent' houses, 25 single-storey with habitable lofts and 8 single-storey, all with mechanical extract systems. Measurements used pressure method and tracer gas in houses with different airtightness, types of window, windproofing and facing materials. Possibility of presetting ventilation terminals and fans to achieve recommended airflows was investigated. Treatsrelationship between wind, temperature and airtightness. Notes number of shortcomings in ventilation system discovered during investigation.

Heat load from passage of cold outside air to building interior is function of wind speed and outdoor air temperature. Analyses meteorological data to determine suitable design conditions for accurate assessment of infiltration heat losses. Terms multiple of wind speed and indoor-to-outdoor air temperature 'wind-temp number' using it as measure of infiltration heat loss caused by wind. Plots these numbers for range of outdoor air temperatures and wind directions.

Reports study of air infiltration through experimental windows installed in a normal office building. Air change rate was measured using carbon dioxide as a tracer gas. Pressure drop across window, wind velocity and direction were recorded . Finds that air leakage measured was generally quite different from that which could be calculated. Postulates reason for this is complex process caused by dynamically varying pressure differential across the window, flow occurring through window in both directions simultaneously and to particular experimental configuration used.

The nomograph estimates air infiltration du to wind and the amount of heat removed by any quantity of heated air. It supplements the September HPAC Data Sheet on air infiltration into buildings due to temperature differences (stack effect)

Points out that difficulty in calculating fortuitous ventilation in buildings caused by infiltration means that energy demand of a building contributed by it is scarcely ever known. Provides equations describing infiltration due to pressure differences, which in turn are caused by wind conditions, inside/ outdoor temperature differences and possible influence of mechanical ventilation systems. Describes computer program developed in Finland to calculate air infiltration. Demonstrates infiltration rates in houses.

Expresses air infiltration rate measured using tracer gas in 2 similar town houses in terms of wind speed, wind direction, indoor-outdoor temperature difference, average rate of boiler firing and fraction of time that doors are open. Method yielded reproducible rates of air infiltration within 0.1 air exchanges per hour in any single one-week run once outside temperature, wind speed and wind direction were allowed for. States results partly reveal set of physical principles determining house air exchange rates which are so far poorly understood.

Sets out simplified analysis of thermal load imposed by infiltration of cold outside air into interior of heated building as function of prevailing wind speed and difference between internal and external temperatures. Treats infiltration loss, structure loss, effect of wind speed on loss. Summarises these values in tables. Concludes incidence of wind speeds in excess of those used for calculation of heat losses at design condition can have a significant effect on internal temperatures. Notes implications for non-attainment of design temperatures in intermittently heated buildings.