Describes a diagram from which heat losses due to infiltration according to German standard DIN 4701 can be obtained, as well as rate of air infiltration per unit length of crack. By considering several factors the method can be generalised for the case of several windows and doors of varying quality of fit. The method is therefore useful for both the approximate and the accurate calculation of infiltration heat losses.
Points out importance of ventilation heat losses in calculating total heat requirements of a building, and necessity of its analysis for multi-storey buildings. Describes bases and possible fields of application of a quick and efficient calculation method. Calculations demonstrate that ventilation heat loss varies considerably from storey to storey, and that a standard storey should not be used when calculating the heating surfaces required for individual rooms.
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.
One cause of these discomfort zones is cold air infiltration through window joints. This can be deflected using a warm air curtain. Describes tests showing that the degree of deflection depends to a large extent on the pulse ratio of the intermixing air flows. Describes chart compiled when experimental results were evaluated permitting determination of volume of air to bedischarged by nozzle convectors sufficient to diminish discomfort zone.
Describes experimental method of determining air leakage characteristics of exterior walls of a building. Method involves pressurising the building with the supply air system and measuring flow rates of outside supply air and resultant pressure differentials across building enclosure. Uses results to obtain flow coefficient and exponent for exterior walls. Checks method by results of computer simulation of a building, finding good agreement.
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.
Reports measurements in title. House was contained in environmental chamber with control over inside and outside temperature with essentially no wind velocity. Observes familiar correlation between inside-outside temperature difference andinfiltration rate, and effect of sealing doors and ducts underconditions of negligible wind velocity. Compares different methods of collecting air samples for analysis and compares SF6 measurements with air exchange rates imposed on the house by means of a centrifugal blower.
Reports results of series of tests on 6 single-family houses to determine rates of overall leakage through windows, doors, walls and ceilings. Uses vane- axial fan to reduce pressures inside house and measure flowrate and resultant pressure differences across house enclosure. Purpose of tests was to assist in eliminating rates of air infiltration in houses.
Detailed analysis of actual space heating requirements shows a much higher consumption in mild weather than predicted. Attributes this mainly to casual window opening, which accounts for 30% of total energy used. This factor will be greater in well-insulated houses where ventilation loss is proportionately greater. Examination of motives for window opening suggests high humidity levels are most likely. The trend to man-made fibres in soft furnishings with low moisture storage capacity accentuates humidity problem.
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)
Login