Derives mathematical relationships for the connection between pressure loss and volume flowrate using simple crack models and applying known laws of similarity for flow in pipes or gaps. Demonstrates how these relationships permit more exact determination of the permeability of cracks in normal building structural components than has been possible hitherto with the use of a few approximate average values for crack permeability coefficients and pressure exponents.
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.
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.
Discusses oxygen requirements and moisture emission of individuals and generation of CO2, odours, and aerosols in inhabited rooms. Treats calculation of hygienically necessary air flow rates. Notes characteristics of continuous andintermittent ventilation, whereby additional outside air is discharged into a room at set intervals when continuous airflow rate falls below hygiene requirements. Compares hygienically adequate, continuous ventilation with intermittent ventilation by calculating hygienically-necessary outside air flowrate using a mathematical mode.
Describes new calculation procedure which forms a basis for 1978 draft in German Standard DIN 4701 "Building heat demand calculation". Defines infiltration heat loss. Examines previous German standard calculation procedure. Outlines basis of natural air flows in buildings in some detail including effect of air pressure and stack effects. Treats pressure distributions affected by wind and stack effects. Describes mass flow balances for 2 building types and infiltration heat losses.
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