English

Gives method for calculating infiltration of a building due to wind and stack effect. Uses equations from ASHRAE guide of 1958, but resolves wind vector into horizontal and vertical components and takes the angle between wind and ground into effect. Method is used to calculate infiltration due to wind for a given building of height h at a distance d from the nearest building with height c and a sample calculation is given

Compares methods of calculating ventilation rates in mechanically ventilated animal houses. Ventilation rates in several occupied animal houses were found by 1) measurement of internal to external temperature and moisture differences using a psychrometer;2) measuring decay rates of radioactive krypton as a tracer gas;3) estimating from manufactures rating of fans. Concludes that different methods agree to within the order of 5 or 10% and suggests the use of psychrometer techniques for simplicity.

Summarises data on air flow characteristics of walls from U.S.A. and Norway. Reports laboratory measurements on four test walls and identifies main sources of leakage for the different test facades. Average air leakage at 200 Pa varied from 5m3/h/m2 to 50m3/h/m2. Shows that wall leakage rate could provide 30% or more of the total leakage rate.

Examines air flow into air-conditioned buildings caused by opened external doors in summer. Firstly the wind velocity through open doorways was measured using puffs of smoke inentrance hallways, finding that velocities varied from 104 ft/min to 350 ft/min with a mean of 265 ft/mins. Then tests were made on the air inflow when a swing door was opened and closed. Finally tests were made of the air flow due to operating revolving doors. Results for various types of entrances are displayed in a table.

Discusses theoretical pattern of pressure differences inside a tall building and describes measurement of pressure made on anine-storey building in Ottawa. Pressure differences were measured across external walls, vertical shafts, stairwell doors and elevator doors with the mechanical ventilation system both on and off. Concludes that pressure differences across external walls depend on the distribution of openings in the exterior wall and of the ratio of resistance to air flow inside the building to that across the exterior wall.

Gives measurements of air infiltration made in ten houses in Indiana using helium as a tracer gas. Assumes linear dependence of infiltration rate on temperature difference and wind velocity and calculates infiltration rate per unit crack length. Change rates ranged from about 0.6 to 1.5 changes per hour.

Gives equations and charts for the calculation of heat and moisture flow due to natural convection through openings in vertical partitions separating spaces at different air conditions. Finds that heat and moisture transfer coefficients depend on the Grashof number and to some extent on the ratio of opening height to thickness. Also gives chart and equations for flow across an opening in a horizontal partition when the higher density air is above the opening.

Reports measurements of infiltration rates in two research houses in Minnesota under different wind, temperature and inside operating conditions using helium as a tracer gas. Suggests linear dependence of infiltration rate on temperature difference and wind velocity. Found infiltration rates varied from 0.1 to 0. 4 changes per hour

Describes typical town centre developments in which a problem of wind environment has arisen, and gives a brief account of the investigation of specific cases. Summarises broad conclusions of 20 special cases. Describes series of investigations intoair-flow around small groups of idealised model buildings and compares model with full-scale measurements. Outlines design method for use in planning layout of small groups of buildings. Discusses future research needs.

Reviews methods of measuring infiltration rates. Describes tests made on a mobile home using carbon monoxide as a tracer gas and measuring the rate of decay. Concludes that infiltration rates depend primarily on whether or not the blowers for air conditioning or heating are turned on. Without blower the infiltration rate was of the order of 0.8 changes per hour, with the blowers it was 1.2 to 1.7. Reported linear dependence of infiltration rate on temperature difference but did not identifya dependable trend on the effects of wind.