Gives theoretical discussion of the neutral zone in ventilation. Shows that the pressure difference tending to cause flow at any opening is proportional to the vertical distance of that opening from the neutral zone and that the amount of air that may be passed by a given opening is proportional to the square root of the vertical distance of that opening from the neutral zone.Discusses the position of the neutral zone in a building which is governed by the relative amount of opening at top and bottom and by the inside to outside temperature difference at different levels.

Reports investigation of air change rates in two residences using helium as a tracer gas. Gives results of measured air change rates, wind speed and direction and internal to external temperature difference. Uses statistical method to compare results from the two residences and concludes that temperature coefficients were statistically different but that wind coefficients were not. Finds high dependence of infiltration rates on indoor to outdoor temperature difference and that values for air leakage obtained from current methods of estimation were lower than those actually experienced.

Ventilation rates in two test home were measured using helium as a tracer gas. Pressure differences across the exterior walls of the house were recorded using pressure taps. Gives results for air infiltration tests and the calculated air infiltration. Finds that during summer air infiltration rates varied approximately linearly with wind velocity. During the winter, the pattern and extent of air infiltration were influenced by both house stack action and furnace operation.

Describes retrofitting a wood-frame residence in three stages to reduce its energy requirements for heating and cooling. The three retrofit stages comprised reducing air leaks; adding storm windows; and installing insulation in the floor ceiling andwalls. The house was extensively insulated to evaluate energy savings and changes in air infiltration rates. Concludes that retrofits produced only marginal reduction in air infiltration rates and attributes this to the original tight construction of the house.

Compares wind pressures measured on a single-family dwelling with results obtained from a 1:50 scale model in a turbulent boundary layer. Shows that fluctuating components of surface pressures far exceeded mean or steady pressures and are well correlated over sizeable roof areas. Suggests that certain current provisions are marginal for tributary areas and excessive for localised area such as ridges, eaves and corners. Describes procedure for expressing loads on both localised and extended roof areas in terms of mean pressure coefficients and a peak factor.

Gives general data about windows in the experimental dwellings and the transport of air through small openings. Describes method for calculating the rate of air infiltration through windows as a function of the pressure difference between both sides of the construction. Presents results for each type of window graphically in several ways. Gives figures for cracks between movable construction parts.

States direct observations of wind effects on real buildings are necessary for the development of reliable information for wind load estimation. Their essential role is to provide data for the guidance of systematic wind-tunnel investigations. Briefly reviews instrumentation used in a particular tall building and the methods employed to interpret the measurements. The review illustrates the potential, as well as some of the problems of field measurements in providing practical information about wind loading phenomena. Summarizes results and discusses their implications for design.

Refers to earlier work by Mattingly, Peters, Harrje and Heisler which indicated the possibility of reducing air infiltration by using sheltering devices such as fences, neighbouring buildings and trees. Reports use of wind tunnel air infiltration model to explore the effect of trees in a windbreak on a model home. Presents results of tests determining the effect on wind-induced air infiltration of the variation of various windbreak layout parameters. Introduces concept of turbulence generation as the mechanism of tree wind sheltering.

Describes the influence on heat resistance of an insulated wall of workmanship and forced convection. Compares experimental investigations on cross-bar walls with calculated values. Examples show the influence on heat resistance of insulation installation, air-flow along the insulation and air-flow through the insulation. Concludes that air-tightness of the vapour barrier and partly of the inside board are of great importance.

Describes pressure method for testing whole houses for air leakage. States main advantages compared to tracer gas technique are that equipment is inexpensive, easy to handle and so well adapted to routine tests. The house is pressurized using a powerful fan and the flow through the fan is equivalent to the leakage through the building envelope at given pressure. Summarizes measurements made on test houses. and shows use of thermography to detect leaks. suggests use of pressure test to estimate the natural ventilation of a house.