Reports tests performed in walls to determine air leakage rates. Lower leakage rates were found with plastered wall than with brick wall and a further reduction in air leakage was obtained by painting the plaster.

Describes tests of air leakage performed on both prime windows and storm windows, separately and in tandem at wind velocities of up to 30.m.p.h. All types of windows were tested and upper and lower ranges for infiltration found.

Describes measurements of heat flow taken in three rooms at different heights in a multi-storey office building. Heat supply, internal to external temperature pressure differences, wind velocity and sunshine were recorded. Gives result that it needs more heat to maintain the same room temperature on lower floors than on upper floors. Difference is that heat needed on 32nd floor is approximately 40% less than that on 8th floor.

Describes measurements taken in eight rooms in a multi-storey office building. Heat supply, internal to external temperature and pressure differences were recorded. Gives preliminary result that wind velocities near building were substantially lower than at nearby weather bureau.

Developes mathematical model of air infiltration based on crack flow equations. Describes measurements made on test house. Shows that actual pressure distributions in walls deviate considerably from values in guidebooks. Finds background leakage area of house by pressurizing house with electric fan and measuring pressures. Suggests two distributions for leakage areas. Measures infiltration rate using helium tracer gas, recording temperature and pressure differences. Concludes that comparison between prediction and experimental results is encouraging.

Reviews qualities desirable in a tracer gas for the measurement of ventilation rates in buildings. Reports experiments in which radioactive argon was used to measure the ventilation rate in a room. Results obtained agreed with simultaneous measurements using hydrogen as tracer. Suggests use of method for measuring ventilation rates in large buildings and use of krypton gas as an alternative to argon.

Suggests energy usage can be reduced by lowering the quantity of ventilation air. Reviews ASHRAE standards for minimum ventilation and air quality. Suggests changes in air conditioning design and the use of air purification equipment. Recommends further research.

Describes the determination of infiltration rates for houses in Seneffe. Gives infiltration rates for individual rooms, found using O2 as tracer gas, and recording wind speed and direction. Determines global air renewal rate using N2O as tracer gas, by injecting gas through ventilators into all rooms and measuring concentration in each room. Calculates global concentration from individual measurements.

Describes how ventilation rates in two houses with recirculating air distribution systems were monitored by injecting CO2 tracer gas into the supply and measuring its concentration in the return air. In one house with solid concrete floor, normal windows and air bricks, ventilation rates were mainly dependent on wind speed. In the other with suspended timber floor and weatherstripped windows ventilation rates were much lower and mainly dependent on internal to external temperature difference.

Refers to previous article treating application of theory of graphical representation in building services of calculating natural ventilation rates in buildings. Illustrates technique using examples of several buildings. Concludes that at themoment this approach is too complex and costly for general application except in specialised cases. Considers simplified methods may be developed suitable for general use.