Discusses the need for shelterbelts over farmland and gives expression for drag force exerted by a barrier in terms of air density, wind speed, barrier height and ratio of wind speed in the shelter to that in the open. Describes field study to determine the effect of a shelterbelt on vertical wind profiles. Presents two-dimensional wind reduction patterns in the lea of the shelterbelt. Calculates drag coefficients for the shelterbelt. Concludes that a shelterbelt can be very effectivein a very short period after planting.

Discusses ways of increasing accuracy and thoroughness of energy audits of buildings by use of specialized instruments and improved audit techniques. States air infiltration measurements are key item in audit procedure. Describes 'house doctor' kitwhich with records of past energy usage, knowledge of prevailing weather and a questionnaire are used to establish the energy signature of a house. The kit includes blower door, infrared camera, temperature probes and appliance consumption meter. Describes simple tracer gas method using sulphur hexafluoride collected in sample bottles.

Describes a simple pressure method for measuring the air tightness of small buildings. It measures the leakage rate from all apertures in the external envelope simultaneously, from which total leakage area of openings could be inferred. Site measurements have shown that obvious sources of leakage like doors and windows account for only the minor part of total leakage area in the average dwelling. Results from 25 dwellings show no trend of leakage area per unit of gross floor area.

A supply of fresh air is necessary in any dwelling to ensure a comfortable, safe and hygienic environment, but the heat loss to this air, during the heating season, may represent a substantial proportion of the total heat loss. This points to the need forgreater control of domestic ventilation, either by using a mechanical system or by better design for natural ventilation. This paper touches upon both of these possibilities. Gives simple method for assessing approximately the possible reduction in heat loss achieved by the use of a mechanical ventilation system.

Gives state-of-the-art review of ventilation needed to control carbon dioxide, odours, cigarette smoke and moisture mentioning main results. Gives sketch graphs illustrating these results. Outlines the effect of opening windows on air -change-rates andgives tables showing average window opening, the moisture generation from various activities and the solar radiation falling on vertical surfaces.

Describes detailed study of infiltration rates measured with a tracer gas and air leakage rates obtained from fan pressurization in small, 3 - bedroom California house as part of a larger study. Finds surface pressure measurements are an essential step in process of finding a correlation between natural air infiltration and air leakage by pressurization. Measurements also show significant duct leakage and air flow between attic, living space and crawl space.

Treats odour penetration from garages etc. into connected room, caused by wind pressure on windward side openings. Discusses measures to prevent overpressure e.g. by a leeward side grill oran exhausting ventilator. Explains with mollier diagrams.

With improved thermal protection of buildings proportion of ventilation heat loss has grown until it now accounts for 50% and more of total building heat losses. Since ventilation cannot be reduced below certain limits for comfort and hygenic reasons, selection of appropriate type of ventilation system is increasingly important to control heat losses. Describes characteristics and consequences for heat energy consumption and hygiene of constant ventilation and abruptly increased ventilation such as window opening etc.

Treats development of generalised model of hourly air infiltration in residences. Describes its testing. Uses tracer gas measurements of infiltration in 9 research residences inColumbus, Ohio, under widely varying weather conditions. Estimates various linear and physical models against 7000 measurements. Measures and correlates weather parameters. Correlation coefficients ranged around 0.9 with an error between 0.1 to 0.36 air changes. presents Fortran algorithm.

Known principles for the prevention of rain penetration and air leakage are not being applied in practice. States that rain penetration requires the simultaneous presence of water, openings and a force ; the two-stage weathertightening or "open rain screen" separates the control of these factors and allows the production of a weathertight joint under practical conditions. Outlines the causes of air infiltration and gives brief case histories to illustrate the serious problems that can arise from air leakage.